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32X
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6
GEOLOGY OF THE YUKON GOLD DISTRICT, ALASKA,
BY
JOSIAH EDWARD SPTJRR;
WITH
AN INTRODUCTORY CHAPTER ON THE HISTORY AND CONDITION
OF THE DISTRICT TO 1897,
BY
H^VROLX) BEA.CH CrOOUrMCH.
87
]
I
llQ^c&
CO NTH NTS.
Pagp.
Introduction li*l
Chaiteh I.— History and condition of the Yukon gold district to 1897, by
Harold B. Goodrich - 103
Early explorations... . - 103
Prospecting of Yukon district up to IHST ^ 107
Discovery of Fortymilo district and subsequent history to 1893. 115
Discovery of Birch Creek district and subseciuent history to 1897 118
Mission Creek -- 119
MynookCreck 120
Condition of Fortymile district 121
Condition of Bircli Creek district 121
Proposed hydraulicking 122
The Upper Yukon 123
Klondike district 123
Difficulties of development 125
Qovennncnt - - 127
Miners' meeting 137
Mining laws 128
Population 129
Production . 130
Table of production (Alaska and Northwest Territory) 132
Table of production (British Columbia) 133
Chai'TEH II.— The geological column . . 134
The basal granite. - 134
Microscopic descrii)tion. . - 135
Age of the Fortymile granite. 137
Extent of the gi-anite area 139
Correlation - 140
The Birch Creek series - 140
General characteristics . . 140
Composition of rocks 140
Correspondence of schistosity and stratification 140
Quartz veins 141
Summary 141
Distribution of Birch Creek schist 142
Thickness of the Birch Creek series 143
Microscopic study of Birch Creek rocks 144
The Fortymile series 145
General description ." 145
Dikes.. 140
Quartz veins 147
Schistosity. .. .. 148
Folding and faulting 148
Joints 150
"«r
90
CONTENTS.
CUAPTER II. — The geological column— Coutinned. Page,
Tho Fortyinilc scrios — Continued.
Composition of FortjTnilo rocks. ' IHO
Marble. .. ISO
Quartzito - - loO
Q>]artz-mic,'i-sc'liist 151
Qiiiirtz-hornblende-sclii.st 151
Epidotic^ schist 151
(TarnetiferoUH schist - 152
Garnet-mnscovito-schist 153
(iraphitic schist 153
Cyanite-schist . l.'iS
Schistose igneous rocks 153
Original natnre of Fortyniilo rocks 153
Distribution of Fortymilo series 153
Thickness of FortjTnilo rocks _ 154
Resume . . 155
The Rampart series _ 155
Preliminary statement _ 155
Distrilmtion and general description _ 156
Fortymile Creek, South Fork 156
Between Fortymile Creek and Mission Creek 156
Mission Creek 157
Betw oen Mission Creek and Circle City 158
On Birch Creek 159
Fort Hamlin to Mynook Creek 1.59
Mynook Creek 160
Between Mynook Creek and the Tanana _ . 160
Megascopic characteristics of the rocks of the Rampart series 101
Classification of the rocks of the Rampart series 161
Diabase loi
Quartz-diabase _ . 163
Olivine-diabase 103
Quartz-olivine-diabase _ 103
Qabbroid olivine-diabase. 163
Serpentine-tuffs igg
Diabasic tuffs 163
Indeterminable tuffs 103
Clay-slate 1(53
Carbonaceous slate _ 103
Impure sandstone 104
Impure limestone. 104
Fine-grained quartzite, or novaculite. 164
Jasperoid i(j4
Schistose rocks . _ jgg
Dikes in the Rampart series iqq
Folding igg
Joints. .. j(j7
Shearzones jg7
Veins -
- - 167
Age of tlio Rampart series jg7
Economic importance jgg
Previous noto.s
I
i
I
1
109
TheTahkandit series. jqq
Preliminary .statement 1A9
CONTENTS.
91
I
Chapter II.— Tho goological column— Cuntinucd. Psko.
The Tahkandit sorips— Contimien.
Distribution anil goneral iloscrii)tioti - - 109
On the Yukon alMvo Circle City 109
Below Mynook Creek 1*1
Near the Melozikakat River 17.3
Correlation ami nomenclature 173
Other areas niaiipeJ as Tahkandit rocks 174
The Missiou Creek series - 175
Preliminary statement - • • 175
Distribution and general description 175
Napoleon and Chicken creeks 175
JUcroscopic characters - 176
Below Fortymilo Creek - 170
Microscopic characters 177
Mission Creek and below. 178
Kandik River and vicinity 180
Correlation - l'?l
Age of tho Mission Creek series 183
Definition of the Slission Creek series - 183
Corresponding strata i" other localities 183
The Kenai series - 184
Preliminary statement - 184
Distribution and general description 185
Below Mission Creek 185
Above Kandik River - 180
Coal Creek -- --- 180
Above Mynook Creek .-- - - 180
Above the Tanana 188
Below the Melozikakat . 189
Between the Koyukuk and the sea --.- 191
The Koyukuk River 191
Correlation and age 193
ThicknessB of the Kenai series 104
Report on a collection of fossil plants from the Yukon River, Alaska,
obtained by Mr. J. E. Spurr and party during tho summer of 1896,
byF. H. Knowlton 194
Description - - 194
Discussion of age of rocks as indicated by plants 195
The Nulato sandstones.. -- 190
The Twelvemile and Porcupine beds 190
Twelvemilo beds - - 196
Porcupine beds - 197
Correlation 198
The Palisades conglomerates - 199
The Yukon silts --- 200
YukonFlats 200
Fort Hamlin to Mynook Creek 200
Junction of Tanana and Yuko-> 200
Above Twin Mountains 208
BelowtheKoyuktik --. 209
Silts between Lake Lindeman and the Five Finger Rapids 210
Interior plateau region of British Columbia 218
Pelly River - 218
Teslin (Hootalinqua) River 210
92
CONTEXTS.
C'HAPlEn II.— The geolofficiil coUiinn— ContiniKMl. V»S»-
The Yiikon silts— Continued.
Kowak chivs and gronnd-ico f (jrnmtion 219
Corrchition - - 210
Age of the Yukon silts 320
The anciont gravels 221
Ancient rolled gravels 231
Ancient gulch gravels - 222
Volcanic ash -' 223
Ci!.\ I'TKK III.— Igneous rocks 224
Basal granite - 284
Dike rocks 225
Dikes in the Fortymile district - - 225
Earlier schistose dikes 225
Quartz-diorite-schist ' 226
Diorite- or syenite-schist • - - - - 226
Diorito-porphyry-schist 226
Later nnsheared dikes - 227
Extremel}' basic rocks 227
Pyroxenite - - - 227
Hornblendite - --- 227
Pegiiiiititic hornblende-diallaite-biotite rock ... . . 338
Intermediate rocks 328
Porphyritic hornblende-syenite 338
Quartz-hornblende-diorite 328
Hornblende-granite. .... 328
Fine-grained hornblende-granite (porphyritic facies).. 328
Porjihyry 239
Quartz-diorite, or granodiorite 339
Acid rocks 339
(traniticaplite. 339
Peguiatoid aplite 339
Dioritic aplite .... 330
Ordinary aplite 330
Porphyritic aplite _ 330
Pegmatite 330
Quartz veins 331
Relation of different varieties 331
Relative age of Fortymile dikes 333
Relative abundance of different dike rocks 335
Dikes of Birch Creek district 335
Sheared granite or granitic schist . 335
Unsheared granite 235
Quartz-feldspar dikes 236
Aplite 236
Dikes on American Creek 236
Aplite 236
Mica-lamproi)hyre. . . 236
Relation of dikes to schistosity 237
Dikes on the Yukon below Fortymile Creek 237
Dikes in the Lower Ramparts _ _ . 237
Quartz-mica-diorite 238
Granite or granodiorite 238
Dioritic aplite 238
<
i
CONTEXTS. yO
CllAiTEn in.— Ih'iicmis roclis— CiintiiiuiMl. "'■'''
Dike rocks— CiiiitiuntMl.
Or.loroi:.lik..ro,-k« ^^^
AiIiM.f (likes -■ - -^
V<)kaiii<; or etlnsivo rocks . . - *^°
Paleozoic— Rampart series ( ilial lases) »oO
Geiieral description ^
Conditions of formation ^J^
Structure and comjiosition of rocks ••- S-*"
Nomenclature - ^^^
Tertiary basalts "■•*
Junction of the Pelly and Lewes •- •■'
Miles Canyon . _ ' [^
Occurrence - "'
Struc'turo and composition ^"^^
Chicken and Napoleon creeks - "44
( )ccnrrence - "
Structure and cpnipoaition j 244
Koyukuk Mountain and below - - 244
At Koyukuk Moimtain - 244
Occurrence and description 244
Strui'ture and composition 245
Between Koyukuk Mountain and Andreaf ski 240
St. Micliael Island 246
Occurrence and general description. 248
247
Craters - - *"
Strnctiire and composition of lava - 248
Porcupine River 248
White River - ■•"
Pelly River ^*^
Resume of composition and structure of basalt 249
A«e of basalts - 240
CUAITKU IV.— Movements in the earth's crust 2.51
Sunuuary of geological records in the rocks 251
(Geological map- - - - ■ _
Division of rocks according to dynamic disturbances 2.^i4
History of rocks to the end of the Rampart series 255
Birch Creek and Forty mile series 255
Rampart series --- - -- ^^^'l
History from Rampart series to end of Kenai series 2oT
Tlie post- Kenai revolution - 2.)i)
Neocene movements - -- '■ '
Mammoth Mountains - - 20i)
Drainage system - - 201
Neocene elevation - 20v
Period of elevation 20.3
Volcanic activity - 203
Minor folding - - ^"■^
Pleistocene movements - - - """
oft",
Submergence - --«■- _
Terraces in the vicinity of the Lower Yukon 805
Terraces on islands in the sea - 200
Terraces on the Upper Yukon and neighboring regions of Brit-
ish Columbia 26S
;i4 CONTKXT8.
CiiAi'Tnt IV.— Mi)vemeiits in the oarth's cniHt— Continued. Pbko.
Pk'i.stoc'cnt' niDVcniciitH— Clint inufil.
.Subnic'iK<'i"'P — Ciintiniii'cl.
Terraces on till' rorciipinc 2fiH
HubnierKenco iniiiciiled by terraces 26!)
Period of ilepression 2""
Absence cif .1,'laciation and rock decay 270
Recent eU'Vdt ion 270
l-;viilen(es of recent elevation in the interior 271
Evidences of recent elevation along the coast 272
St. Micliail 272
Unalaska 272
UnKa 272
Other localities 27.1
Conclusions as to recent elevation... 274
Recent warpings as shown by drainago jieculiarities, hy Haiold B.
Goodrich -. 270
Alaskan drainage as»illnstrated by Fortymile Creek 270
General aspect of country 270
Activity of Fortymile Creek - . . 276
The ancient valley 276
The present valley due to ujilift 278
Rivers as measures of warping 278
The Yukon 279
Fortymile Creek 280
Mission { 'reek 281
Mynook and Hunter creeks _ a82
Birch Creek ^'83
Causes of asymmetry of streams 28.5
Theory of differential in.solation 285
Theory of terrestrial rotation 280
The eflfect of geologic .structure 287
The effect of tilting 287
Summary 28!)
Ch.vptkb v.— Valuable metals in solid rocks 290
Quartz veins 290
Occurrence 290
Divisions in point of age 291
Metallic contents of older veins 292
Metal 1 'c CI intents of younger veins . . 298
Microscopic occurrence of gold 294
Mineralized shear zones _ 294
( )ccurrences 295
Genesis of aiii-iferous ijuartz veins 297
Transitions between veins and igneous rocks 298
The origin of diflferences in igneous rocks 300
The process of difTerentiation or segregation 301
The chemical variations of dikes 302
Order of succes.sion of lavas 304
Nature of the segregation processes 30")
The pn icesses of synthesis or mi.xing 307
Contact metamorphism 307
Modifications of wall rocks 307
Modifications of intrusive rocks 3O8
Atmospheric mixing 303
T^
CONTENTS.
96
CliAlTER v.— Valuable metals in solid rocks— Cnutinucd. Paw".
Genesis of auriferous (innrt/. vi'ins— Continui'd.
The plienoinena of segregation j"^'^
Contemporaneous increase of silica and water ... !i"U
Contact phenomena of acid rocks 810
Crystallization of granite "11
Crystallization of pegmatite 81 1
OriKin of certain quartz veins 818
Source of gold in qnartz vein .- ■ . -. 818
Gold in igneous rocks - - '"3
Mineralogieal relations of pewmatites and quartz veins to iKiie-
ous rocks in general ... -i^'-i
Manner of concentration ''' gold -'l-l
Manner of solution and ,;" oipitation of gold •114
Observed connection of gold-quart-' vein- with intrusive rocks. :tl5
Summary ''^'^
Cli.viTEH V'l. -Placer deposits -• 817
Gulch diggings - 81 1
Fortymile district 317
Discovery 817
Bed-rock geology - - 818
(Geological maps 318
Description of gulches -- ■-- 319
MillerCreek 8i0
Shape of valley - 330
Gravels 8-,n
Sourceofgold ■-■ 833
Glacier Creek- - --■ 834
Shape of valley 834
Bed-rock - 335
Gravels 325
PokerCreek - 826
Shape of valley 327
Bed-rock 828
Gravels 828
Occurrence of gold 829
Davis Creek - - 830
^ Shape of valley 330
Bed-rock 380
Gravels - 331
Sourceofgold 831
Chicken Creek 831
Bed-rock - 832
Gravels .-. 833
Franklin Gulch 332
Bed-rock - 333
Nature of valley. . - 833
Gravels - - 833
Napoleon Creek 33.)
Shape of valley 335
Bed-rock _ 835
Gravels. 336
Mission Creek district 337
Geological map — 837
Description of gulches 338
I
i :^!
oc
CONTENTS.
CllAi'TKU VI.— Plnccr (lepiisits— tVmtiimed. Pane
(tnlch diggings— Coiitimied.
MissiiiH ( 'icuk district— Continued.
Description of gulclies— Continupd.
Mission ("reck ,._ _ ._ ;t;i8
Nature of viillpy 3;iS
Bed-rocks. _ _ ;!;i8
( )Ider gravels :i;i!)
Younger gravels ;i3i)
American Creek ;j39
Bed-rocks. . ., 339
(travels.. 340
Mammoth reniiiins . 341
Birch Creek district - 311
Discovery _ 341
General geology 34 1
Geological map .•!43
Descriptions of gulches. . . 313
Hog 'em or Dead wood Gulch 343
Valley ;!CJ
Lake accumulations 343
Bed-r( icks ,'j4,'[
Gravels ._ 34;)
Greeidioru Gulch 34,-)
Independence Creek JU,")
Valley ;).(,-,
Gravels _ ;j4(j
Mammoth Creek ;{40
Mastodon Creek ;j47
Bed-rocks ;j4g
(Travels....... ;j4fj
Miller Creek.. .'jio
Tojiography __ jyg
Gravels _ ij,-,()
Porcupine Creek _ ;),-,()
Harrison Creek ;i,-,|
Bed-rocks _ ;j.-,o
Shape of valley ;j,-|.i
Gravels ;),-,o
Source of placer gold... ;).-,;)
Eagle Creek . ;j,-,^
Mynook Creek district jj,-,,-,
Discov<>ry ■^-~
(xeneral geology .. .__ ijjg
Descriptions of gulches ggg
Litth^ Mynook Creek 355
V"ii«T ^....V " V''. am
Bed-rocks _ ;j-,(j
<-riiv<'U '^\.. 'im
Hunter Creek 3-,^
Shape of valley 353
Bed-rocks (j^,).j
Gravels y^jj.)
CONTEXTS.
97
m
Chapter VI. — Placer deposits— Continued.
Gnlcli (liK.ijiiiLts — Cuntiinied.
( )tlu'r tjulcli iligfjiiifjs
Kliiudiki- district _
Upper Yuk( 111 -
Shi^vliii Creek
The Kiiyukiik
Bar diiiKiiiK'*
Manner (if formation .
Helation of liars tn j,'iilch diKSings
( iccurreiices (if fjold in liiirs. . . _ ._ _
Ancient and Inssil placers _
Klevated aiirilVidus gravels
Fo.ssil placers _ -
Xapiili (111 Creek _
TheKdVukuk _
Conclnsioii __
Metals iitlier than gold in placers
Origin nf placer gdid of Yukon district _
Derivatiiiu of gdld from certain rock formations _
Distriliution (if rich gulches with reference to geological .slruc
ture . . -
Gulches in Birch Creek rocks. _
Gulches in Fortymile rocks
Gulches in llanijiart rucks ._ _
Source of tlie detrital accumulations in gulches
Manner of concentratio". of gold...
Processes of mechanical concentration
Possilile cheniical iiitiiieiice in concentration..
CiiAi'TF.u VII. —Coal in the iieighliorhood nf the gold belt.
I )ccurrences
Charaileriif cdals _
Economiit values ..
CaAl'TKU VIII.— Summary and jiractical applications . .
Summary of report... . ... .. _
Practical applications of geological principles.
CllAPTKR IX.- Methods I if mining
Bar diggings
Cradlin.g .
(iulch diggings
Sluicing
Burning and drifting
18 (JKOL, PT 3 7
I'ano.
ar.o
359
!i60
HOO
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;trtO
ao3
8«;i
:!l!4
•.m
•Mir,
mr,
mr,
JifM
3(!6
;!iir
;mT
3li7
371
371
•.i7i
375
375
377
3S0
3«i)
381
Wi
38)
383
38li
380
3Hit
389
3!)0
:!ni
il '(
11 LI' ST RATION'S.
J
Platf. XXXII. Map of Alaska, slinwitit; ninre traversed by Ttiitcd States
(ieiilofiical Survey jiarty ill ISIM) _ _._ Hll
XXXIII. BdwMer of Keiiai coiiLtloiiieriite upiir immtli of Tiinaiia . . iss
XXXIV. Ontline ii;a]i of tlie Lower Yukon and vieiiiity 1110
XXXV. The Yiikoii Flats 200
XXXVI. End of Yukon Flats and lieirinniuK of Lower Ramparts ','Oi
XXXVll. I )utline map of the Upper Yukon and vicinity 'JIO
XXXVIII. (Tt'olofiicalmaiiof the Yukon f^old licit and ad.iacent rcfjions '.'V.'
XXXIX. Data mail of the Yukon },'old l)elt and ad.iaccnt re^'ionv '-'">'
Xli. Terraces alonj,' the Yukon in tlii' vicinity of the Hay i{i .'cr :.'lil
XLI. Strait between St. Michael Island ar.d Whale Islaii' •-'TJ
XLII. Face of niorainal knob ad.ioiniiif.^ strait shown in Plai. XLI TH
XLIII. lieacli at llinhuk, Unalaska Island, showing niarini' ter-
races _ - - '.'TO
XLIV. Map of a portion of Fortymile Creek, sliowing relation of
ancient and present valleys _ ','Ty
XLV. Maj) of F<rt'tymile Creek and vicinity HIT
XLVI. Topographical and Lieoloirical sketch map of eastern (lortion
of Fortymile Creek ^Mld-miniiii; district ft: pocket
XLVII. TopOf^raphical and geoloffical sketih map of western jior-
tion of Fortymile Creek ^rold-miniiiLC district ■i\n
XLVIII. Topoi,'raiihical and geoloKual maji of Mis.sion Creek f;(ild-
mininij; district _. . - :i:l7
XLIX. Map of a portion of lUrch Creek :llo
L. Topographical and geological map of tlie Birch Creek gold-
mining district . _ In pocket
LI. PoHsIkmI specimens of (juartz from Deadwood ami Fortymile
creeks _ - . -Wi
Fui. T. Marble cliffs df Fortymile series. Fortymile Creek, below O'Brien
Creek 1 10
M. Faults in Fortymile series. _ _ l.'iO
0. Kneading in aphanitic limestone of Tahkandit series. Lower Ham-
parts . ..._ i;a
10. Skelchis of disturbed strata of Mission Creek .series... 177
1 1 . E.xposure of Palisades conglomerate underlying silts. 1911
\-i. View at the head of Lake Lindemaii. 'ooking west . .. 310
i:i. Bowlder-clay, silts, and gravels on the Lewcs just below the Teslin
I tlootaliiii|ua I '.M.'
II. Diagram showing folding in silt Mulfs mi the Lewes above Miles
Canyon . . '.'bt
|.-|. Basalt. White Horse Hapids -Jl:!
Hi, Diagram showing .iomting of basait on Koyukuk Mountain, on th^
Vukon . •-'(."i
'JO
10(»
ILLUSTRATIONS.
Fiii. K.
IN.
'.'11.
•,M.
25.
Kxtiiict cr.Ttcr oil St. Micliiicl Isliind - 247
Kiitlinl ^[l)lllltain. Maiiiiiiiith UiiiiKe ■ ~61
Anticlinal liill aii<l synrlinal valley on Yukon River near mouth
of Tahkandit Kivcr - 264
.hinctiiiM 111' Forlyniilc ('ri'cU and Smith Crt'ek_ 277
Norlli-sidi' <-ut-oir and d.'scrlt'd mcandiT on llnnti'i- Creek . 883
Sketch of c mtiirted and .shredded (|nartz vein.s in Fortymilo schist. 291
ynartz-tVldsiiar vein in sohist, Sontli Fork of Fortymile Creek l?!t2
Dia,i,'iani of ideal river, sliowinj,' acemnnlalion of bar.-; 861
DiaKram showing saw-like form produceel by erosion iu originally
level-topped schist ridges 376
4
247
.'01
>64
32
iCl
no
EIGHTEENTH ANNUAL REPORT, PART III PL, XXXII
-|0«
-irfl
t^ Moaifled from r i Coast Survey Chart T aeoordlng
^ to exploratlont • XT. S. Geological Survey Party In
" charge of J. E. S;-.t— 1896
Bed dotted lines iaote routes followed
Dashed lines dm:- areas shown on larger scale maps
Scale
1897
■■--i-.
i!
: I
^ . . ' i
ikWm
\ ^--^
ll 1 i
J^it.
ULlua fliENftCO I
» -*
GEOLOdY OF THE YFKOX (iOIJ) DI8TRI(!T, ALASKA.
By J. E. rSPURR.
TXTRO UrCTTOX.
The Hold work on wliicli llic accoinpanyiiitr roport is hassinl wnsdono
in the siiniiut'r of J8'.m; l)y a party consisting:;, hcsidcs tlic writer, of
Messrs. H. H. (loodricii and <'. !•". Scliradcr, assistant j,'('oiof,nsts. Tills
party left ■Wasliinfjfton at the end of May and rt-tnrnt'd abont the
middle of October, and tlins was enal)led •<< spend nearly four inontlis
in actual field work in Alaska ami ad.jactMit portions of the North-
west Territory. The route pursued is show n on the i^cneral iiuiji of
Alaska (IM. XXXII) which accompanies this repoi't. l-'roni .Iniu'au
our way led ui> Lynn Canal and tlien<!e across ("hilkoot Pass to Lake
Liiideinan, whlcii is near the headwaters of one of the several irreat
rivers which mute to form the Lower Yukon. From Lake Lindeman
we ti'aveled in a snuiU open boat tlirouj^h lakes ami rivers to the
gold-nuiuiij;; disti'Icts. After examluln;; these we rowed ami lloateil
down to Xulato, where we obtaim-d jtassaite on a tradlnjf steamer to
St. .Michael, and at St. .Michael took passauc on the .Vlaska Commer-
cial Company's steam.ship Bertha to San Kranei.sco, via Tnalaska and
I'njfa. On the trip from Juneau ti) Foi'tymlle Post, which occupied
about four weeks, we were accompaided by Mr. P. A. Wlbory, an
Alaskan pioneer miner; otherwise the journeys made were without
a.ssistants or camp hands.
In the preparation ol this report valual)le assistance has been ren-
dered l>y Messrs. (ioodrich and Schrader. The published nuqjs were
prepared larj^ely, and In some cases wholly, from our lield sketches;
aUli<m}rh in those covering; considerable areas the Coast Survey inai)
has been used as a basis. This work was done by Mr. (ioodrich, who
has also prepared the ])reliinlnary chapter on the history and pi'esent
condition of the Yukon gold district , as well as a discussion of the ilrain-
aji'e peculiarities of the fj;old belt, which ai)i)ears as part of the chap-
ter on movements in the earth's crust (Chapter IN', p. ^ol ), and reports
on f^ulches In the placer districts visited by him. Mr. Schradt'r has
prepared separate reports (Ui frold-produciiiK gulches and has given
help in the microscopic study of rocks, in obtaining a full knowledge
101
•J
lll'i (il'.OI.oCV UK TMC, YIKoX liOMi DISTKK T, ALASKA.
Ill' ihc lilrniiiirc cjI' ilic siibJi-cN Ifciiicd. .'ind in nijiiiy Dllicr wjivs.
.McNMs. !■'. II. KiKiwlluii. \V. II. D.ill, Clijirii'.s .Schiiclicrl.- Daviil
Wliiic, T. \V, Siaiilnii. F. .M, Lucas, ami liaNlil'ipni Dean liavi" I'cii-
(li'icij |ialf()til()l();,dcal a.ssislancc. and .Messrs. W. I'. IliJNdtrarid and
II. \. Stokes have aidcij hy llicir clifiiiical work.
In llii' lii'ld, wlicii' ilic most dilliciill jiaii ol' the work was jicr-
foniicd, (•oiiiii..si(.s wore icmiIitimI by the .\laska ( oiiiiiicrcial Coiiipanj'
and Ilic Xoith Ainciican Tr'ansipoiialion and Tiadinj; ('i)ni|ian\, lo
wlioni llianks arc dnc .sincere a<d<no\vlcdirinenls are also jjixcn (o
llie Alaskan pioneer niiners, o|ien-licarIcil and open-handed. In w lioni
wc are indchicd I'o, many a lo(lj.inii- and many a meal. Finally, an<l
above all, llii> writer records his thanks to his I'rionds and coworkers,
.Messrs. (ioodri<'li ami Selnader, to whose i)er.soiial support and cndiir-
aiicc of physical discoiarorl and (lan{,'er a large part of the .success of
the nndertakin.u' is due.
«
:i
C II A PT KR I .
IILSTORV AXl) COXDTTIOX OF TIIK YtnCOX <;(>M>
DISTHHT TO 1H1»7.
By II AUDI, n n. (toiihukii.
EARLY EXPLORATIONS.
Tt was the fur !ra<k' llia( led tlio Kiissiaiis step In- stc]) aloiin llu^
Aleutian Islands from the (ifst (liscovcrics of I'.i'rinjr and Cliirlkuf, in
1741, \nilil (lie tinx' of liaranof and tin' .m'cal l{nssian-AnnTi<'an
nidniipdly. With tho orjrani/alion of the latter and llie liiilits of
oxclusivinrade jiranted it the Uussians, olilaininji' a fcmtliold on tlio
southeast coast, advaneed into I.erin},' Sea and even up the K\viki>ak
(Yukon) Kivei'sonu' "xio miles. While this eonipany was spreadinj;
eastward fioni the I'acifie and JJoring Sea, the Kiiiilisli, lepiesented
by the N'oi't Invest Company and later liythe Hudson I iay Company,
were simullaiM'ously itushiuij their trade westward. In 1Sl>1 tlio
KortliwesI and Hudson liay companies fo (1 a union. They had
posts on the .Mackenzie River, where their servants lived and carried
on business over l.iHH) miles fi'om the nearest civilization, receiving;- in
retni'U salaries hardly larire enoujih to buy the ordinary necessities of
life. The hardshii)s of these pioneers were many, but they pushed
onward in the face of all dillieulties, lookiufi for new tields where a
lucrative fur trade could be carried on; and in this extension of tho
fui- trade tho idea of another passajfe to the Pacilic was kept eon-
stantly in mind. As early as 17Si; La I'eronse had, in behalf of tho
French (ioverument, underlakon to solve the problem of a northeast
passage to the Canadian hikes or Hudson May from the western
shore of America: but after .sailinfj as far as Litua Hay he becanio
convin<HMl that the northeast passage had no existence. In 1S|(J
Kotzebue sailed on the same <inest, an<l for a time thouf^ht himself
successful.
In 1834 .1. McLood explored tho Liard Hivei' above Fort Ilalkott in
the endeavor to discovt-r some westwanl-flowin;;,- stream that miiiht
lead to the Pacilic coast. On '.his trip ho disi!overe<l Dease Lake,
103
104 (iKoLoov oi' Trir. yikdn com) district, ai.ahka.
and rid.sscil Id the IiokI nl' llu'Slikiiic. wliicli he callcil I'rily Ifivcr,
liiit uhirli was al'tcrwanls iiaiiii'ii rraiircs Uiver, ill lioiiid' (if Laily
Siiii|iM(n.
Ill |s:)s liiiliiTl Caiiiplpi'll vcdiiiilccii'ij til cslalilish a Fiiri mi Oraso
I.alvc. Ill- |iassc(l llic wiiilcr llicic. liiliili^' wliicli lie was rnliiccd
aliiKisI 111 .slarvaliiiii: Imt siil)sc(|n('iil l.v llif jmsl was almmlontMl,
1 aiisr ill llic iiicaiiliiiii- Sir Ocdivi' Siiiijisdii had scciiri'd t'niiii llio
Kiissiaii (;<i\(iiiiiiciil lli(> It-asc of llic •'cuasl slrip" uf Alaska in
faviir (if the lliidsun Ita.v ('(iiii|iaiiy. and all tlif furs uf the Slikiiio
l{ivi'i' fniiiid llicir way In iiiarkct mhui' easily at tlic jinsl liiiilt at Ilio
iiimitli of thai liver. Tor lliis |iri\ile^re A:.',iiiiii aiiiiiial rental was
jtaicl by llie eomiiany.
Ill ism Deaseaiiil Simpson. Iiavini: recently discovered tlic month
of the I'olville Kiver <in llie Aii-tic coast, wished to llnd its lieatl-
waters. It was siipjioscil that this river's course was parallel willi
that of the .Macken/ie, and that therefore waters llowin;; into it wmdd
lie I'liund in about the latitude of the head of I''rances Uiver: accord-
ilijrly. in the sprin>,' of the year an expeilition in chary:e of Uoliert
C'aiiipliell stalled from l''oil llalkell.oii llu^ Llard, asceiide(| t In- stream,
and discovereil and nanicil France's Lake. He further asceiideij Kin-
laysoii Ki\er to the lalce of the saiiie naiiic, and from there crossed to
the I'elly, which he nanied in honor of ii pivernor <if the conipany.
In lS4i' I'elly Uanks I'osi was estalilisheil at a point near the head of
Mil' Pelly Hi\cr. In .rune of the followin}; year t'ainplH'H descended
the I'elly as far as the mouth, and the Lewes River was named, lint it
was not until isf.i lluit Fort Selkirk was foiiiiile(l at the junction of
the two rivers.
While Campliell was ojieninjr the Lewes River country, voyagers
were also liiisy in the country to the iioi'th, and another post had been
established by the coin])any on the Yukon. In 1842 .1. l><dl made a
journey across the divide between feel Hiver and the Porcupine,
and descended the latter a short distance. lie returned to Fort
Mcpherson, on the Peel Itiver lu'ar the mouth of the .Mackenzie, and
was in chai%'o of that post in lS4ii, when, pursuant to orders from the
tradin;^ company to repeal the trip, he descended the I'orcupino to
its mouth, and in 1847, two years before Campbell had settled at Fort
Stdkirk, Fort Yukon was built. It was not I'Vcii known that the two
were upon the same stream until is.'id, when Campliell descended to
Fort Yukon, and was much surprised to lind a white trader at the lat-
ter place. Duriii}; this and subse(|uent journeys Campbell named
many of the ti'ibutaries of the Yukon, tienerally in honor of friends
and associates, and most of these names have become (i.xeil by common
usage. Amonfj these were the Stewart and White rivers, the former
named for one of his assistants and the latteron account of the muddy
character of its water.
From Fort Yukon Campbell made his way up the Porcupine, crossed
to the -Mackeii/ie, and returned to Fort Simpson provinjr that the
lllSloHY ANI> CONDITION.
lO.-)
niulf to till- Viiknii l)y wiiy nl' I lie I'drciipiiif was iiMicli casiiT iiiid los
iliiiiK*'''"'"^ ''"'" '''"' ''y "iiy III' thf l''iiiiifi's tn I'lPil Selkirk; iicriiril-
iii;;lv. in l>^"iii iiiui l'"^'"'! Ilif |"imIs at KdiM Kraiu-i's aii<l l'i'll\ liaiiks
were al)aliili(iii'ii. Fori Selkirk was. however, si ill niaiiilaiiie.l as a
Irailint; |(osl until l"^"'-. In Hiis Near llie eoasi Imliaiis. eni-aued al
llie serious inroads wliscli the posis of llie iiilerioi' ueie niakili;: U|)oii
llie Iradi' llu'v liail previously niiiiio|ioli/,ed. deieiniined upon a
raid. 'I'lu' Cliilkals erossed llie divide in .Xiiuusl. surrounded i-'orl
Selkirk, and. in I In- ahsenee of llie friendly Indians. I lie in males were
ilrivenoul and llie huildin«;s sacked. ( ainpludl, liavini.: ualhered liis
torci's. Iried in \ain to appndu'ud tlii' rolioers; aflcr wliieli. Iiein^oul
of prDvisions, he was oMiired lo lloal down llie river to l'"ori ^'ukoll.
whenee he returned to ['in\ Simpson late in the f.all. The same wintei'
hetraveleil to .Minnesota on snowslioes. a m pi isliin^r a. joiirnex unpar-
alleled in Ihi' annals of the lludsiui r.a\- ('ompan\ . 'I'henee he went
lo Chiea^'o ami Ihe KasI ami sailed lo l.ond(Ui. where he plai'ed the
matter- liefiu'e Sir <;e(M';,M' Siniitson and asked for permission to rees-
tablish Ihe demolished jiosl. This was mil alhiwed him. and until
, par.'ilively recently Ihe site of Fori Selkirk was nmrked only liy
Ihe ruins of the old l)uildin,u:s. M iire.sent .Mr. Harper manages a
tradinji post al this loealily- the lirst one wiiieli the t!a\ eler me<'t.s
on descelidilif; the ri\er.'
Fori Yukon was occupied as the wesleninHist imst of Ihe Hudson
]{av Company unlil after the transfer of Ihe Territory lo the I'niied
States. The trip to this point from t he western coasi was not made
till lsti:i. when it was accomplished li\- an employee of the Uussian-
Americaii Conqiaiiy, Ivan Simonsen I.ukeen. Aceordiiif: to Dr. \V. II.
Dallr' Liikeeii wa.s s<'nt by Hie I{ussiaii-.\nieriean Company to investi-
gato rumors of llie exislenee of an Kiifflish Irailini: post far u|> the
river, which they knewbylhe name of Kwikiiak. It seems that even
before this lime trijis had been made by Kiissiaiis up the river lo
Xowikakal and by the Kii;,disli down lo that point, but the men had
never met, and the Yukon and Kwikpak were sujiixised to be distinct
streams, the one entcrinjj Ihe .\r<'tic Ocean and the other entering
i;eriii,u- Sea. In ISdii Ketchiiin and Lebarsic. of the Teleirraph Kxpe-
dition, ascended fi'om St. .Michael as far as Fori Selkirk, and proved
conclusively thai the Kwikpak and the Yukon were identical.
Previoiisto the transfer, the Kussian-.\iiierican Conipan\ had occu-
pied Iradinir posts on the river as far u)! as Niilato. haviiii;- enlered
the Yukon country from the Kuskokwim. near the head of which Kol-
makof had established the redoubt, but with the openinj: up of the
T< -ritory that coini)any yielded in favor of the Americans, and seveial
coi.. aiiK'S immediately entered the field. The Kurdish were aceiis-
toi' d lo send men down to Nuklukayet every sprin};to j;atlier in thi'
1 It is i-.'iiiirtiMl tlint Mr. Hnrpcr. one ot the nldi'st i>ii.iieer.s trf the Yulii.ii. dieil ..I' .■..iismnpti'.ii.
after liis retufii t.i .he T'nitert Stiites, in I)i nilier. isiir.
■',\ kii ami lis Kesourees. Biwton. 1^711. pii :.'Tii -J".
I(i6
(iEOLOi.Y OF Tin: VIKON (idl.U DISTRICT, ALASKA
t'liis lliiil liiiil Ih'ci llc<'tc(l (lliiiii,i;(lii' witil.T. Iiiil in lSl;^. w licii ilicy
iiiailc llu'ii' usual amiual trip, tlicy foiiiid an Aincricaii •foinpaiiy,
wliicli liad ascend. '(1 llic river lln' snninici- Ix'forc anil located tliere.
The latter inl'onned tlieni that they cdidd no liiniicr jmrsne tlieir
tiade niMin Arneriean soil. It had Ihmmi siispecled tliat Fort Vakoii
was well within the Alaskan lioMndai'y. alihoni,di its loeation had
lievei' been .iclually dc-terrnined : so in \^<'''.K wiien a eonipany of
American capitalists liad t'ornied the project of trading on the Vnkon,
it was thoii,i;liI best to deternuMe once t'oi' all whethei'any I'ln^iisli
Conipanx hail the riuht to carry on trade at the month ol" the I'orcn-
pine J{iver. To this end Cajit. Charles W. Havmond was detailed 1o
make observations of latitude and lonuitude at tin' conllueni'c of the
two rixcrs. 'I'lu' party ascended the rixer in a steamboat — Ihelirst
tinn'tliat one hail Moated on tlie Vid<on. (»n tlie :ilsl of .Inly. ISiiii,
they arrived at the post, ha \in.i;- accomplished the joiiiney fi St.
IMichael in twenty-three da\s; and on the 7tli of .\ii.uiist observa-
tions of the solar eclipse were uniile, which settled tlie ipiestioii finally.
Fort ^^lkon was fonnd to be in .Vniericin territory, ami a few days
later the llinlson l!,iy repi'cscntativcs were informed that it was
illetial for them to trade with the Indians on I'liited States soil, and
thid they must vacate their biiildinjis. Captain llaynnind then look
possession in the mime of the I'nited Stat(>s.
In report ini; 11 pini the resources of the country from observations
made on this trip, ('ai)lain Ua.vmond i-oncludos that the itn|iortatn'e
of the fur trade had been greatly exasiit'i'iilcd. As tar as mineral
wealth is coiicerneil, he dismisses it wit h ;i siiii;le sentence. '" No valu-
able niincr.il deposits in workable i|naidilies hii\e been found u|) to the
present time." In this is shown the attitude which lh(> trading com-
panies lijid maintained and the policy they had pursued in the devel-
opment of the country. Their attetitiou had h.'cn directed <'ntir(dy
to the fur trade, to the exclusion of all other resources. Xor was this
attitude always a pas.sive one. The story is told ' that when l!arain)f
was chief inanaiferof the liussiaii-Aiiieriean ('oni])aiiy. a Russian who
had been exiilorinu' the iiiouidains ba<'k of Sitka found several pieces
of rich (|Uartz. Jiaranof assa.\ed the speeinieiis. but told no one of
the result, and (udered the tinder to do no more prospecting;'. The
idea that the mountains of the coast of .\laska coniaiued mineral
wealth had been sun'u'ested : but even ajiainst the re])i>ate(l eH'orts of
th" Kinperor to have his realms invest iirated, the .■iji'ents of the coin-
l)any interposed objeetioiis. their real reason probabl.v beiuff that an
increase of |)opulation resultinji from a di.scovery of jjrecious nwlals
Would have u'r(>all,v lessened their iirollts. I''inally. in IS."),"), an euLji-
neer, I)arrehan,' was sent by the Kinperor toexamiiie the shores. For
some reason this ollicer made no exa'ni nation of I'.araiiof Island, where
' Ri'|)t. Dii'iTtoi- v. S. Mint iiimn in'iKiiii'tiim nf pi'i'i'iciiis ini'tals in r. S. ihii'int,' Isst. p. lii.
2 TliiM namt' is a miupriDt foi- DoroHhiii. oi- l)nro--'r, in thi' rei)o)*t citt'd.
llooliKlcll.
lUSl'dRV AMI ( ONDITION.
1(17
fidlil w.'is .-iricrwiii.is luiui,". ill Is'iS, ami liis ntlii-f iii\ I'sti^ai imis lia\-
iiii;- pfdvci! iiiisalisfaflorx'. Iii' made an iiiilav orahli' icpnrt. Wliilo
tile Kiiirlisli I'liiiipany look no sik'Ii |Misili\c sianil as this, il lu'vcr
(lid any prospect ini;- nor in any \vii,\ ciicoiirairfil oilicrs to do so.
I'liil it was soon sccii tlial tlicrc were otlwr icsoiiii'cs JM'sidcs t'lirs.
and a iii'W (dcinciit licnan to coiiii' into proiiiiiii'iii'i\ In I s.")7 llic
Hudson l!ay Conipanv liail ri'cciN nl t'roiii its agents on tlir i-rascr ami
'riiotnpson rivers in liritisli (oininliia. or Xew ( aleclonia, :!nii ininees
of irold wliieli liad lieeii collected almost eyelilsively liy the Indians,
who were very jealous of the white Mien. 'I'lie i,'i)orl sent by (Jo\ iMiior
Dolijflas caiiseil the greatest excitement amoiit;- the liordes of miners
in California who had not recovered from the attack of ■"n-old fe\er"
produced li.Nthe dis<-overy of 1S4S. As one writer lias said. ■•The
third ureal Devil's Dance of the nations within the dcea<le seemed
about to heiiin." Thirty thousand miners went iiiimedial(dy to the
scene of the excitement. Ilara.ssed by the Indians aloii.u' lh<' route,
they were ohlip'd to liiilit fre(|iienlly for iiossession of the land: suf-
ferinji' was mreal ami the riotous scenes of lhci;<ild cra/e in (aliforiiia
were to a certain extent repeale<l. In l.s,")'.i tlie P'raser Kiver distrii't
wasocciipie(l, but all except M.nooof those w ho had entered the country
ret II rued. The lollow inii' year the Cariboo district was disco\-ered. and
after that the Omciiica, althoii!:h l)ut little work was done in the latter
until l^i'i7: and in l>!7f came the Cassiar. and later the discoxcry of
irold ill the vicinity of Sitka The tide of jrold seekers was setlinu
steadily tiiwai'd the nori li. and it is not siir|)risinij: that, havinj,' found
irold alonir all tiiese mountain ranges, prospectors should licifin to
think of the \ast unex|)lorcd interior.
PROSPECTING OF YUKON DISTRICT UP TO 1887.
Tlie llrst iiredictioii of the discovery of tiold in fhe interior of
Alaska had been made by Mr. W. I'. I'.lake.' In isc,:! he visitiMl the
Stikine Hiver. in what was then Hussiaii .\merica. .\t this lime,
althoiiuh ])lacers were beinji' w-(jrked near the mouth of the Stikine and
).:ravel bai's were payinj; iis liijih iis xlii per <lay totlie man. the reu:iou
wliieh was afterwarils known as the Cassiar district had \h'ou little
pros])octed: but, on makiiiii' an examination :leiidin,ir •")" miles up the
river, lie came to the eo;icliisioi) that "there is every reason to believe
that the jfolil rcfjfion of tiie interior extiMids aloii.tr the moiiutains to
thoshoies of the icy sea, and is thus conne( led with the uold rejji jus
of Asia.'- This may seem a very sweepiiifi ficnerali/.ation c)ii slijj:ht
jrrouiids, but coming from such a source it undoubtedly exerted an
inlluence in turning the attention of prosjieetors toward the interior.
Anollier prediction— though not intended to apply especially lo t i;c
I House cif K.'p. Kx.Dciiv ITT.iit.u". Fortiotli ('(iiinn>ss, mivuihI scHRiim.ii.4,
'U'l'iifi'-s'irniiilo' n'nmil<»ui|i. cit. ji. ilitlmt thi' until Urniiul'.t l.vtlu' liuliuiwli itln Tiikouii
vTiiliui Hivi'i'. furtlii'r imrtli. whh iimi'li iMiii'wr tlinn timt IhiiikI upon tlie stikiiif
I(l8 GEOLOUV OK TlIK YUKON' GOI.IJ IHSTRKT, ALASKA.
^ iikciii (•(iiiiilry— wiis iiiiulc in a Icltcr of .Mr. II. II. .Mclntyrc lo tlio
Si'cfctaryof llic riiitod Slalcs 'rrcasmy in isip'.t. Mv. \h-li\\y\v caino
III ihc coiicliision, from the siniilarily in liCDlogifai slrnt'tnre of the
.•^iciia Nevada .Monnlain.s of Califoiiiia ami Ihc Rocky ]\roniitaiii
r'anj^csof .\iasl<a. Unit il was rca.sonaliic to cxpcci miniM'al wealth in
tlic iattci-.
.V little while liefoi'c this, howcvci'. tiie lindiiii; of " minute specks
of udid "■ liy some of the Hudson Hay Company's men on the A'tikon,
l)rol>alil,\ iTi 1 lie \ ieinity of l''oi't .Selkirk. Iii-itish tecritoi'y. was i'(?ported
to the \\'cste!ii I'nion 'ri'lcitraph H\|)cdition. Hut this ydld was not
in quantitii's to wanant a •■ fush" to the locality.' .Miont this time
Dr. W. II. Da II wrote:-' ■"(iold i)i small quatities is found in the sands
of the Nukoii neai' I'ort Yukon." In ISi;7 Ketchum and l.eliarjic,
memliersof t he Teleurapli Ivxpcdit ion. ascended the ^'llkon and found
evidences of uold on the iijipcr river.
The fin'Ciroinj;' were casual oliserval ions, however, and it was not
until(4eoruc Holt's li'ip that sy.slemalic jirospeclinfj^for jjold was liej^un.
The dale is somewhat variously jriven as 1S7l', IS7."), ' and. liy Dawson,
JS78. It is certain that Holt made several trips. (Mi his lirst one lie
crossed the (hilkoot Pass and descended the Lewes Kivei' as fai' as
Lake ]\larsh: icturniim from lliis point by way of the Teslin (Iloota-
lin(|ua '), Dease Lake, and the .siikine Jtiver to the <'oast, he liiouaiil
back jrlowinjf accounts of ci- so jjold on the upper Lcwos. It is said
that in 1874 he descended the Yukon as far as the one hundred and
si.xtieth moridiau, aiul ci'ossc(l the water portajie which bei,nns a1 the
Kussian .Mission to the Ivuskok wim.' Holt appears not to lia\c 1 ii
entirely relialile. and many of his stories of adventure have been dis-
credited, but. be tlnMlatcs ot' his Journeys correct and his tales true op
not, he was the lirst prospector who reiiorte(l jrold from the Yukon.
In IXS.") he was the au'cnt of the .Maska Commei-cial Company at Kiiilc
Hi\('r. on Cook Inlet, when, Inuinj; incurred the enmity of one of the
Indians, he was murdered.''
Soon after (Icorfie Holt's first tri|), in 1S7:!, Hariicr, who was Ilio
a.u'eiit at Foi-t Selkirk, ami I''red Hart, at that time employed by the
Alaska Commercial Company, but who has for a number of years been
a successful mimr upon Fortyniile, wenton a i)rospoeting tour in the
St(>wai't- and \Yhite Uiver countri<'s. They I'ouml line itold. but no
}Iood prosiiects on \Yliii;' River, and absolutely nolhiiifi; on Stewart,
which was th>' scene of h>t or excitement. Hart attributes their failure
to discover jrold upon 1h(> latter stream to the fact that thov did not
I TiavclH ill Alnsltn and im tho Yukon, Wliyiiipor, Lnmldii. 18(111, p. aw.
'^ Alaska ami its Kosonrcfs. Lumlon. 1S7(). p. 477.
' Aldska Ciiast I'ilut, Ittfvl. p. U1»l.
'Till' I'liitcil stall's Biiard <m (ii'iiKrajihic Xanii's lias aili.iiti'il Ti'slin as tlm imiiio iit tliis riv.'r
anil lake, nftin c.-illi'il llimtaliniina.
■''.Iiinrni'ysin Ala.ska. K. Kiihainali Si'iilmniv. p. I 111,
■' Shim's anil Alps iif Alaska. It. W. Si'tnn Karr. I. niidMii, |s.s7. p IMI.
HISTdKV AND CONDITION.
l(i:i
iisiMMul tlic SIcwMi'l I'lir ciioiiirli. Had llicy inadc tlic «lisc()\ci\ the
i-usli Id llu iiiiliy would li!i\i' ipcciirifd Iwfhi' yi'iiis rarlicr.
From tiiiic to time rcporls were Imiufjlit out l)y such iiifii as Holt
wiiicli stiiuulal ■<! iiiincrs and prospcclors to a rush for the interior,
'riic only [tract icalilc routes lay o\ ci- tin' ])asscs in tlic Coast Han,i::c to
the sjrcat watci-courscs. 'riicsc jiasscsaro four in nnnilicr: from noitli-
ucst losonlheasf: the Chilkal, Cliilkool (I'crr'ci' I'ass of Scliwatkai,
Wliilc. and Taku. Of tlics,' the Cliilkool ami White are the nearest
in direct line with the hemlwaters of the I.ewes. the finiMcr lii-inu :i,riiKi
feel above sea level, whili' its nei,ij;lil>or to the south is fidly l.("iti feet
lower. However, not willistandinj,' tlic p'eater rou^'hiiess <if the .i<cir-
iiev, the tMiilkoot i'ass lias been abnosi invariably >;eleete<l, jn'obably
because it is less interrupted by portajies, and the .journey from salt
water to the lakes at tlio head of the river, only l'7 miles, is much
shorter than by any other route.
It is related ' that the lirst jiassajre of llii' Chilkoot I'ass was made
in isiil or ISCi.") by an employe(> of the liudson I'.ay ( oiupaiiy. who
start e<l from Fort Selkirk, was imprisoned by the Chilkoot Indians, and
Avas liiially delivered to Captain .'^^waiison, who thou had command of
one of the company's steamers in Lynn Canal. Dr. (i. \V. Dawson
does not cre(lit this story, because a1 the time of the alleged tri|) l-'ort
Selkirk was in ruins and had been so for twelve years: but traces its
oriji^n to the fact that shortly after the raid upon the fort a iruii and
seviM'al other articles belonffinu' to Caiiipbidrs party were recoxcred
on the coast by servants of tlw ciunpaiiy.'
From time immemorial the Chilkoot and Chilkat Indians inhabitiiiii
the coast had maintained a monoiioly of the trade with the Wood or
"Stick" Tndiansof the interior. Fii barleriui;-, the latle!' were .illowed
to come as far as the pass, where they were met li\- the ( liilkools and
exi'liautjc was made. Their iiosition as inlei'iiiediarics between the
interior Indians and the whites was iireatly to llii' prolit of the Cliil-
kats. and they a|)|ieai' always to have resenl<'d any interference with
this position. In writiiii;' on this siib.ieet, in ISCO .Mr. ^\'. S. |)odi;-e
says: "Nor will the coast Indians permit any while man to pass to
the up[ier country to trade: the jienalty they t lireaten is death. \\[
ti'ade must be ma<le with them and throuj;li them. Hence is evinced
a monoiioly powerful and e.Ktensive in character."'' This altitude of
the Indians undoubtedly delated the develoimieiit of the country
several years, for all parlies which started out for the interior with
the pur])ose of prosj^'ctiii}; were prevented from crossini;- I he Coast
Kanye, with the e.Kceplion of (ieoi-fxe Holt, who, as nieniioned above,
made the passajje.
I K. li Siiilmori'i Aliisliii. iis Simt.n'i'ii ( 'mist, and tli" Sitlinii Ari-liii>elnK"- P H" "'"' '■I'*"'-
Wlll'I-L'.
- .\iin lii'iit li.'cil Suiv Caiiiiilii IssTxi". Vnl. Ill, Part I. I'^wi. p. IT!" H.
' Sonati' E.\. Ill"' Nil ""H. Forty lilt li ('"iiKross, tliinl si'iwiou. jillT.
110 (iEOI.oiiY OF THK YL'KON (iOI.D DISTRICT, ALASKA.
In ScplciiilM'r. is7'.i, tlio Iiidiiiiis rciiiovcd nil llioir ulucctioiis ti) tlio
while riicii ciitiTiiii: I heir (•ouiitry, "wiiiir t<> the ilii)l«niiali<' llilcrccs-
sioii of Caplaiii IJcardsIco, who was llii'ii in fliarjrc of IIr' ({ovcrnniont
vessel Jiniiisliiini, slatiimeil at Siika. Dnrin;: the winter a jtarty of
nineteen orjrani/eil in Sitka nnder the hsKlershiji of Kdinlind liean, the
same who wiili a party had landed at Taiya (l)yea') in .May, IsTs, and
had lieeii prevented from iiroeeedinu' to the interior at that time.
They were liirnished with an escort ami hole letters to he presentecl
to the chief of the trilte, Klot/.-Kntcli liy name, whose father had been
instrumental in the raiil upon Fort Selkirk in 1S,')J, and who him.self
had recently irix en some iroulile to the (iovernmeni re|)resental ive.^
The party. ineieasiMl to the number ot' J."i, landed safely at Taiya. Tho
Indians, rec(iu;ni/.inj; the authority and letters sent to them li,\' Captain
iieard.slee, helped the jn'osjieetors by supplyini; packers, and on .liine
17, l.ssii. ih(. company had crossed tliedi\ide. The disco\-ei'y of <j:okl-
bearinjr Icdiics near- Takn ami the development of rich n'old placers
and ledues discovereil by Joseph .Inneaii in Silver Uow Hasin, .just
abo\('the town which now bears his .lanu', occur'red in the same year.
'I'he removal of the endiario fni'lhermore o|iened the interior of
Alaska, which before this li.id been a terra iiicoirnita. I'^rom this
time, then, dates the devehipmeiit of irold mining' in Alaska.
.Vs a result of this lir'st prospectinjr party's work, the tliidin^ of
jjold-beai'ini; bai's in a small sircani which Hows into the Lewes I.5
miles above the '-anyon was repoi'ted. The stream referred to is
probabl.N' (,'ummins Creek, which in IS'.i:> was worked and yielded ^;)
to ><■") per clay pel' man. \{. Steel, oiu' of the members of tho prospect-
in}; i)arly. reported on tliiscicek >'L'.."iii |)er <lay per nniii. Tiieir move-
ments after' this are uncertain. In the.Uaska Coast Pilot foi' 1SS;{
Ca|)tain C.irroll states that some of the members went down as far as
l''()rt ^'nkon: others went up the I'elly Hiver .'i") nnles to the I'elly
Hanks trailiiii; post of the Hudson I>ay Company. Here the latter
[ta It y separated ayain, some takiiij;' the northern branch to l'(dly Lalvcs,
ami others iroiiiir ' <> P'ranees Lake, in the Cassiar country, where they
fell in with se\eral other prospectors ami ])resuniably stayed for some
tiiiu'.' |)i'. |)aws(iu's version is that they ascendecl the Tes-lin-too
(Teslin, or llootalin(|ua), and prospeeteil its bars, ret urn ini; by the
sanu' route.' In the same year at least one other pai'ty ci'ossed the
Chilkoot Pass.
In ISS| iiinr miners crossed thepassand prospected the l>iu: Salmon
Hi\-er. aii<l these may be sai<l to bi' the lirsi iirodiu'ini:' mimu's in the
^'ukoii district, (iold was reporteil the whole Icnuth of the lyon, or
liiii' Salmon, ami I \vo of the mend)ers, Laui^try and .McCilinchey, did
considerable plai'cr miniiiu' in the ii\er bars of that stream.
' Till' fiiitcil stiiti'N lliiiird nil (iccwriip'.iii' Xiimi's 1ms uilnptiMl Tiiiyiias tin' I'unii of tliis iiaim'.
■^SiMiati' V.\ litif. Nil. 7l.F(irty-sfVt'ntli CoiiKrt'ss.llrst s.'ssi.in.ii, iMi.
' Ala<lia r,ia><t t'ilot. l.W). p. -^ti
< Ann. Ui'pt. ifuol. Si.rv. L'aumlu I.HKr-s.H. Vul. Ill, I'ail I, l.-v.i. p. l.^^i H,
(lodl.HH'H.l
HISTORY AN1> CONIHTION.
Ill
III tlic followiiijr yt-iir, 1^?^-, an I'xcollciilly dP.'.-iiii/cil ..\|m .iii ion
jUlriiii)ti'(l lo i)ros|)cct llif Yukon from tin- oiln-r end. In .Inne llif
imrty, consist iui,' of 1.") prospt-ftoi's iiiulertlii' Icnlcrsiiiii of Kiiw.nii mimI
KIT Sciiicniin, (liscovcrcrs of s,'ol(l at Tonihslonc Arizona, wml loSl.
.Mi('lia("i,l)oiig!i1 tlii'stcanilioal \i ir /.'-/cAv /, ;in<l asccmliMl ili.' Yukon as
far as Nukhikayet, where lliey winiered. Alxuit :!i«i niile> .il.ove Die
nMiutlitlieyaresaidtohavetliscovereda '■ mineral I lelt." 'I'liat falitliey
prosiie<Me<l sonn' small ereeks and rivers so nnle> aho\ .• llie Iradini:
post at Nuklukayet, where they found bars yieldiii.- ''lo a <lay per
nuin, and in prospeet every pan showed jrold. •• There were many
good indieationsof gold, especially in the reirii>n wln'iva r;inircof liills
known as the Lower Ramparts are aligned with the river's course."'
They returned to wiii'er ipiarters at Nuklukayet. hut in the spring of
jss:i started up the river again and fonml iilacers paying -slo to s];, at
Howetka.' (The latter point I have been uinilde to identify. I During
the sui'uner they returned to St. Michael, sold the Xi ir llnrhl. and
reached San Francisco by the revenue steamer Curir'ni. Tlieii' con-
clusion in regard to the country was that it wouhl lo'ver pay for nnning
operations on account of the severity of the winter ami the shortness
of the opi-n season, but, while dissatislied witii 'he opiiorluidt ios
alTordcd for mining, the Schielllins must have been mueii rat died at
proving to their own satisfaction, at least, their theory that there is
a great •'mineral bell "' eiu-ireliiig tlie world from Cape Horn through
Asia and the Vcw \Yorld. They had found this mineral belt at
several i>oints along the Yukon. •
Thistrii»is interesting mainly because, while all the former |),()s-
peeliiig lours had been in Mritish territory, this was the tirsi report
of the linding of gold in the rniled State> jiossessions. Further, the
ereeks and rivers referred to were witli<iut doubt .Mynook and Iless
ereeks, which have been rediscovered comparatively recently and have
been worke(l only during the past season. Thirty miles above the
mouth of the Taiiana River a large creek enters the Yukon from the
east. It is called by miners an<l t raders Shevlin (reek, ami so spelled.
This is proliably named after the leader Schielllin. '
In ISSl' it wasri'iiortc 1 that a company of b"> miners found gold b'lH
miles east of the Copiier, or .Vtiia, River.' This is [irobably a refer-
eiu-e 1o Scliielllin"s party, which coiisislecl of .ibotit that number. In
the same year iminy miners crossed the ChilUoot I'ass. an<l oui' party
in whi<'h was I'"rank Deiismore. a man now famous through llie whole
Yukon country. asciMided the Felly as far as lloole Canyon." 'i'lie
results of this trip were not especially encouraging.
lUi'pt. I)il-i'c-|..r I'. S. Mint. 1>M. p. :.1'.
'JOp. i-it., p. •.".'.
"OiiMiiy Hi. ls!i;.l-;a\vanlS.-liii'minilii'cliitCaiiyn:ivini-.(ir.-i;..ii. .\Uli..unli liv Miinl.M.v.-i- li.-ilf ii
inilliuii rlolhirs lint ..r Ills di.MMVi'i-ii's in Ariz..iiii. In- .li.'.l I'l lu.v.Tty. liiiviuu- v,,uiiii.l.-r.Ml \\U
luuin'y ill Viiriinis niitiiiit; vi'lituros.
< Ann. lifiit, Dir.i-tcii- I'. S. .Mint. lw<;i. p. 'M
"Ann. Iteiit. ("111. Sui'v. Ciiniulu Issr.sx. p. l.'.ii B.
11
112
JKOLOOy OF Till'. MKON (iOl.D DISTRICT, ALASKA.
Ill jss:! tlierc was sonic niiiiiiiy in river bars (in llif I.cwcs, but
ri'iiorts arc very incajrcr. This was llic year Ilial Scliwaliia niaib' his
I rip on a Miilitary reconnaissance, lie notes tlic iircscncb of j;ol(i in
jilaccr deposits, lic^iinniiif,' al llie iiioutii of a river wliicli lie called
the D'Abliadic. but wiii.'li is now known by the name Uiis; Salmon,
and colli inninjiiilniosi lotlic nioulh of lhe}ircat Yukon. He says that
"a panfnl of dirt taken with discretion from almost any bar or bank
will, when washed, jrive .several colors."' At Von Wilczeks Valley,
I'll miles south id' the I'elly Kivcr, colors were I'oiind in the hijih bank
near the river.-' The author concluded Ihat most ot the yold came
from the I'elly l{iver, because the bars at the iiiouth of that stream
were a little I'iclu'r in placer {fold than othei's on the Yukon: also
because reports of successful small niinin^' on the Pcdly, jirobably
rcferrinji' to the party iiieiit ioiicd above, had been broujfht down to
Fort Selkirk.
.Vnionj; the 200 oi' niori' miners who crossed the pass in the s|)riii<j;
of iss:; was a prospeelor named Diinaii, who, with his party, was so
well satisfied that he sent out to .luncau in the middle of the season
for a year's siiiiplies, intcndiiii; to remain tli iiiiie. His messenuer
niaile e.xtravajfant reports of jilaccrs yieldiiij,- -^l.")!! a day to the man.
A later ])arty, auain, told of uravel bars yieldinjf -^J.") a day. ' Several
parties besides that of Duiraii spent the wilner of lss;i ju the inlcrioi',
ainoim' theiM lieiiii; one on the Copper Kiver, reported by ('ai)taiii Car-
roll.' who failccl to state whether they had found any i;oo(l prospects.
In the fall of issy some miners broii.uht into the town of .luncau, which
was by that time a llolirisliini;' community, sl.iMiii nf coarse j;old, which
they asserte(l came from the ^iikon. This caused yreat e.xcitemcnl,
especially as there were then al .hineau many miners who were oul
of work, owiiiii' to the icccnt aiiand.inmcnl of the Cassiar district in
llrilisli Columbia, and was one of the causes of the rush of the follow-
ing;' spring-, when over oOli men v''osse<l the suinmil.
The Cassiai' distrii'l was, in a way, llie traiiiinii: school for Yukon
miners, and to the experience uaiiied there the latter owe to a irreal
extent their ability to cope with tlii' natural disadvanlajfes, for the
conditions are similar in each. The early miners wore oblijjcd to
enter the Cassiar held oxer a sleeji mountain trail more than l.'id miles
lonif, briiiifinif all their provisi<ms with I hem, ami when lliey arrived
had to conlend a;;'ainsl severe winlers and short workinji' seasons, in
a country fai' from the base of snpiilies. Cassiar traditions, then, had
fi'reat weiiihl amon,u' the lirsl miners of the ^■llkoll, and Cassiar meth-
ods were followed; Ihcrefore it may not be out of place to jii\'e a short
history of the jirowlh and declim> of the Cassiar ' dislricl.
I .M.iMu .Maskn's Itrciit Rivi'r, p. 1!N1.
•n.i.l.. 1.. -.ii:!.
■Ann. Hi'iit. Uirc.'tui- r. S. Mint. I.SS.1. |,. :m.
' Ala..ilm ('ua>,t I'iji.r. l!*.'':!. |>. u1»i.
»t'u.<»ittrlsii curniiitinnof fli,' nani.' Kaskii. ii],iiU,.tl i,, tw.i ti-ib.'sot Iiuiiiins iulialiiliiiB Hiia
region.
uoonBicH.)
HISTORY AND CONDITION.
113
Thoillstrict lii'siu Ihotlrainafjebiisiudf tin Liiinl and I )casc rivers,
in IJritisli C'oliuiibia. Dcaso I^akc issitiiatcd at about tlic cfiitcr. ami
iho area is also coiisidcrcd lo iuciiid.' liic Stikiiic Kivcr. Iti \:w tlio
fur traders (irst discovered tlie Stikiiu* Itiver, whieli iiad not l)eeti
reeopiizcd by Vancouver in 17n:). In IS.-U the Hudson i!ay Company
sent out, a vessel with sup|)lies I'or a post at its mouth, l)ut wore pre-
vented from eiitablishiny; the post by the Russians, who ovected Fort
Dicmysiuson the spot now occupied by Fort Wraiifrell; linally, how-
ever, in 1837, a compromise was arranged and the I'ort jjassed over to
the possession of the English coni|iany with the lease of the "coast
strip" of Alaska. Several times Fort Stikine, as the post, had been
renamed, suffered attacks from the Thlinkit Indians, once narrowly
escaping <lestruction, but it was still held as a trading station for
many years.
In 18i;i two miners, Choqiiette and Carpenter, discovered gold on
the bars of the Slikine. Excitement was great, mining parlies were
outlitted at Victoria, and river-bar placers began to be worked. Two
years later a Russian exi)edition was sent to ascertain whether tlu!
mining operations wer(( being carried on in Russian territory. Mr.
AV. P. ISlake acconipanicd this expedition and embodied his ob.serva-
tions in a report from which we have ipioted above (p. 107).
In 1834 3IcLeod entered the upper Stikine near Dcase Lake, hav-
ing come overland from Mackenzie River. Afterwards Mr. R.
Campbell, noted in the records of the Hudson Bay Company, win-
tered on Dease Lake, but the post established thei'c being rendered
unnecessary by the lease above mentioned and the consequent con-
trol of tiie fur trade from the moulli of the Stikine, it was abandoned
in 1839. From tiiat time until 1S72, when Tliibert and McCuUoch
discovered rich bars on the Liard, no while men entere(l the country.
These two men were trappers who had come from the East and had
wintered near Fort Halkelt in 1871, where they found coarse gold and
worked a bar known afterwards as :\[cCullocirs bar. The jiext year
they reached Dease Lake, and descending to the mining localities at
which mi-n were then at work, reported the news of gold discovery.
In 1873-71 there was a rush to the count ly; production reached its
highest point, a small town was built, ami cattle were imported, but
the sui)ply of gold was not found sutlicient for the supjHirt of any
largo number of people, and from year to year tiie iinnlucl fell oil", as
is shown by the following table (p. 111).
18 GEOL. PT 3 8
114 (iEOI.OQY OF THE YUKON GOLD DISTRICT, AI.ASKA.
.Miniii;/ jKipiilaliuii and pniductiini -;/' tiald in >lic Cusniur distrkt from ISf.', to
ncfiil ni'iirs.
Y.'iir.
Mining ])opu-
liitioii.
Proiliii'tion of
Kold.
$1, 000, 000
830,000
550, 474
490,830
519, 720
405, 200
297, 8.50
198,900
182,801)
119,000
101,01)0
50, (100
(13, 010
60, 485
43,325
23, 935
22. .575
IXM . ...
2.O00
S(l(|
1.500
,1 1.300
L.-^oo
•is:5
l.sTd
1ST7
1S7S
1879
18S0
I.SNI ..
18X3
18*i
l.Oiii)
1S,8-I ...
1885
18Stl
1887 .
1888
1893
1*195
(I Ono-third ChinoHO.
When llu' placi'i" deposits luul become (^xluuisted it was found
impractical )le to work the auriferous <iuartz veins, on account of the
fjrcat ciisl of iiiipoi't ill!.;' iiiac.'liiuery; so, in 1884, as lias been said, the
. diiisjinu's were abaiidoneil, only a few Chinese beinj; left to woi'k over
the rich tailinj^s. Dr. Dawson, writiiij;; in 188S! of the .Slikine River,
■says: " \ot more than -SI to !?:$ per day can now be jiot [from the river
bars], ami work has i)ractically ceaseil."' And since tliat time the
decrease has been stead}' until now, when the district has no import-
ance. The abaiidoniiienlof the Cassiar re}j;ioii, 1h(>n, gave an impetus
to travel over the Chilkoot Pass, and dui-ing the year IS.si- there was
some milling on thePellyand Tesliii rivers, and on the former one
party, it is said, took out x7(H) by bar washinjf. "i'hei'e were sev-
ei'al other encourafrinj;: reports by prosp(;otors and travelers in the
interior that year. Amonj; them was that of .S. H. ."\[cLenei;an, who
was detailed for duty in the exploration of the Kowak River in 1884.'
lie says: "In rcLtanl to the e.xisteiicc of .trold in this region, there
seems to be little donl)!. In almost every stream, large and small, we
found the color of gold." He refers to the prosi)ecting of the Yukon,
which had then but just lieguii, and, like Schiefflin, canie to the con-*
elusion that mining could never be sm-cessfully carried on, although
' Cniliu ot thu United States Reveinu Steanior Contiii, 1)W4, \i. KIT.
ir. :'i
nOUKHK'M.]
HISTORY AND CONDITION.
115
at till' sanu'timp ivlinitting that placer miiiinj,' iiiiKht Iw iiiadi- n-iiimi-
erative if largt.' (l('i)(>sits <'((iil(l hv found.
In l!SS.") the rusti to the interior continued. On Stewart Wiver live
parties prospci'ted and \vorl<ed placi-rson the river bars. .Mi tooli out
some golil, and good prospects were found, the l)est results, liowever,
lieing tliose of one party of two men who worlicd for four niouliis
"rocking" on a bar about lOO miles from tJienioutli and sui'ceeded in
maiiing *-'r),0(K). WIumi tins l)ig lind was repcu'ted an inlluxof miners
occurred and much plainer worlv was done on bars along tiie Tpjier
Yulvon. The more advanc^cd stage of gulcli ndning luid not l)e<'n t ried.
The niollu)d followed was by rocking, tlie iiuplement used bduj; lliu
sanu- as tlie California cradU — a bottomless box set upon rockers aiul
divided into tlirco compartments. In tlie upper one tlu' gravel was
thrown and, by setting the rocker in motion, was sifted through a
sheet-iron niesli into the lower coiupartment, in which a cloth cauglit
the finer sand and gold and strained the water. Tlie iiuiterial thus
collected was then taken out and panned with the ordinary hand gold
pun. With slight variations this is the process still wherever bar
placers are being worked.
With this primitive method of working, Stewart River was pros-
pected for 200 miles from its mouth, antl while no well-defined ipiart/.
ledges were found, placers werediscovcreil that are estiniate<l to have
yielded ii((iO,000; whicli, in addition to all other placers on the Vukon
'(*1.5,S,5S.SH), made the total for the Yukon country f(»r the year
¥7."i,S.').S.8.S.
The successes upon Stewart River were followed in the spring of
188() by the discovery of Cassiar bar, 10 miles below the mouth of the
Big Salmon River. Fifteen dollars (ler day per nmn was reported, and
the output has been estinuited at *:.'0,000. Stewart River still con-
tinued to produce well, but in 1887 its yield decreased to *5,000, ami
the placers were almost deserted.
'
i
DISCOVERY OF FORTYIVIILE DISTRICT AND SUBSEQUENT HIS-
TORY TO 1893.
The reason for the desertion of the Lewes River and Stewart River
diggings was that late in the autumn of 188(i a miner imnied Franklin
had discovered gold near the mouth of Shitando River, called Forty-
mile Creek by the miners, on account of its being +0 uules below the
old Hudson Bay Post, Fort Reliance. As soon as the news was reported
a stampede followed; the center of population was transferred and
the camp of Fortyinile was founded. In antici[)ation of the great
rushthatwouhlfoUowtheannouncemcntof thediscoviM'y in the spring,
it was thought best to send a letter to Mr. Mc(Juesten, the agent of
the Alaska Commercial Company, who was wintering in San Fran-
cisco, asking for an increased shipment of supi)lii's to iTieet the increased
demand; and, although it was the middle of winter, one (ieorge Wil-
116 (iEOLOGV OF THE YIKON (JOLP DISTKICT, ALASKA.
liaiiis vdluutooml tocarry lliis li-tU'rover the Cliilkout Puss. Willium.s
liad Ih'cii a vivi-i' captain aii<l kiu-w iiolliiiifr whatcvi'i- alxmt winter
ti'avi'liiig; but, alllniiij:li his frieuds tried to dissuade him from tiie
attempt, he persevered, and with one Indian aceomplished the trip,
one of the most danj^'orous over ina(h' in Alaska. He had many
accidents, owing to his inexperience, and wlien finally he was nearly
a1 the end of his Journey a l)liz/,ani arose, which prevented him from
crossing the suniirdt. lie was therefore obliged to build a snow hut
and live there until threatened starvation forced him to cross the ]ias8,
although the storm wasstii' raging. At thesnmmit his strength gave
out and he was carried to .Sliee)) Camp on the Indian gniile's back.
There they met some Chilkat Indians, who sledded him tlu^ rest of the
way to Ta iya, where he died from t he elfoets of the exposure a few days
later. The letter, however, was delivereil and .sent to JIcQtiesten.
In tile latter part of 1S87 Franklin Guleh was struck and imnied in
honor of the discoverer of Kortymile. Cabins were built, work was
begun, and during the first year the creek is estimated to have pro-
(hii-ed *l,lt()(». Kver since it has been a (-onstant " payer." The char-
acter of the gold found here is nuggely, masses of *5 weight being
very common; and Franklin Gulch has the rejintation of having pro-
duced the two larg(!st nuggets in the Vukon, one worth *.")0() and the
other i§i2:!9. The lirst was found by Conrad Dahl in 181)4. The dis-
covery and working of Franklin fTulch marks an advance from the
primitive bar working to the gulcli diggings, in which sluicic boxes
are used, and the current of the stream is nuide to perform most of
the work. However, bars were still worked all along Fortyinile, and
the jiroduct therefrom forms a large proportion of the total.
The yield the first year after the discovery of Fortyinile has been
variously estinuUed at from *75,O0U to *150,0()() bui *fiO.OOO, given in
the table, prol)ablj' covers the iiroduetion.
The discovery of Davis Creek and a stampede from Franklin (Tulch
followed in the sjiring of 1888. The finding of other creeks and the
wholesale working of river bars probably increased the yield by at
least $15,000. Data for 1888 and 188!) are, however, lacking. At the
time reports were extravagant, but in retros])ect it seems that the
amount gi-\en in the fabh is not far from right.
In 188!) Foker Creek and the headwaters of Walker Fork were
staked out in claims, but while there has been some placer working
on the latter stream ever since, it was not until last spring that the
claims of Poker Creek were worked.
The first estimate of the production of the Vukon i)lacers appears
111 the report of the Director of the Mint for 1890. It is placed at
*50,000, which is in all probability too small a figure. In the report
of the governor of Alaska foi- the following year it is said that the
Yukon placers produced one-third more than in any other year.
In 1891 Dr. C. W. Hayes, who went down the Lewes to Fort Selkirk
rinoitlltf It.
HISTORY AND (OXIHTION.
117
^'1
'M
iiml ci'dssed up the While Hivci' to Uic ('()i)|ii'r, reports ilmt In men
were at work on I'iver bars. Ap|)areiil ly the davsoT llie river bars
\VLM-(.' ]iassetl. Oil Cassiar liar 4 or "> men were not ivroilueinu inueh.
On the other hanil, liie reporls from I'orlyniiie were very eneoiirai;-
in;;. Oti the ocean trip ha<'k to Seattle several iiiiiiers lirou;:'il witli
tiieni alwHil s;i(iii apieee. Two new ereeks Avi-re slniek in this anil
the sneeeeding year.
Aecoi'diiif;- to an estimate liy the yovernoi' ul' Alaska, based mi con-
versation with miners who Iiad come oul and rejiorted jjrreat richness,
the ])rodnct ol' the Nnkun district was siT.'i.OOt). We have taken the
mint, estimate, showin,!,' double the oul pulof 18!MI, us bcinj;'thc r(>
consei'vative ol' ihe Iwo. althoujrii Ihis, on the other hand, is pinbably
too low. Certain it is that in Ihis yea i' y;oUl minin;,' in the interior, as
well as on the coast, al Silvi.'r l!ow l)asin and 'rreadwell. r( ived a
great impetus.
Tlu' eveiil of Is^'.iJwas Ihe discovery of .Miller (reek byO.C. Millei',
a noted prospoL'lor bi Ihe ^'nUon counlry. Il had 1 n prospecled a
great deal lieforc, bnl had always been i;iven up bcc.iuse the ^ravid
was so deep I hat the labor involved in striiipinu' iiuide it unixolilablc
working. In the lirst year of actual work, however, one claim is said
to have yielded '<:)(l,iMiii. In Ihe spi'ing of IS'.i'" many new claims were
slaked, and it, is cslinialed IhatsniiuMi look out «bio.iMi(i. Since that
time .Miller (reek has been the heaviest jiroducer of I lie i'"orlymile
district, and, iinlil rccenlly, of .he whole Yukon. Its entire length
lies in Urilisli jxissessions.
About Ihe same lime (dacier Creek, which lies next to th(> nortli of
Milk r Creek, also ill llrilish territory, was discovered. Its |iroduct
was probably not great during that year, the same dilliculty of deep
gravel obtaining there as upon the former. The total output of the
Yukon placers for bSicJ sliows an increa.se of ><10,(Hii) over IS'.H.
In the s])ring ol iS'.i:! Ihe re[)orteil I'ichness id' Ihe inlerior caused a
rush of minens, over :>iin men being em|)loyed in Ihe I'ortyiiule dis-
trict alone, and a result of this increase in poonl'ilion waslliat pros-
pecting was more vigorously undertaken. Manyjiarties made long
trijis of discovery, and among these was one in which were such men
as O. C. .Miller, Langford, Sinclair, and .Myuook, all noted |)ioneers,
who j)rospected the Koyiikiik Uiver for many hundred miles from its
mouth and brought liaek favorable reports.
An eslimale of Ihe output is given in the rejiort of Ihe Dii'cclor of
the Mini, as follows f\). 1 is), all the gulches and ere(d<s nameil being
in American territory, with Ihe exception of Miller Creek.
118 (ilCOI.OdV tiK THK YCKOX GOLD DISTRICT, ALASKA.
Mi)iiiiil IHijiiiliitiiiK iiikI i/iilil iir'iiliifliiiii ii/'.I/k.sA'Kh (Ti'i'Am in JSH.I.
Fdrtyiiiili' .. .-
Xngfj''' ••'ilcli .
Friinkliii (tiilcli
Diivis Crcok
Miller Creek .
nettle's Mine. ,
GoUl Hill Mine .(
Pilker Gulch....
MlnlinJ ]Hii)ii-
lutloii.
I "~~
3
■1(1
(?)
Total
I'rixUii't.
$2ri, 00(1
l.'iOO
;!.i. 000
:i(i,ooo
100,000
2. 500
■t.ooo !
1!)('>
I'.IS.OOO
II Not workf'i.
DISCOVERY OF BIRCH CREEK DISTRICT AND SUBSEQUENT
HISTORY TO 1897
T)i tlic siiniiiuM'df 1803 Pitka .iiid Soitcscip, IJiissiiiii lialf-bi'ccds who
li;i(l riiiMicily \v()ik('(l ill (111- (liyLciiies <m P'ortyiiiiic Creek, re])(irte(l
tlie liiKliiii;- 111' u'dlil nil llii'ch Creek. At llii,' time lliati llie news was
reeeive(l al I'lirlyiiiile I'ost there were many (liscoiiraiicd miners t(i
whom Die iKissiliililies (if a new district oll'ered elianees to retrieve
thciil'iirl lines. .Many ol' them did not iiave enoiluli money to buy
oiillits I'lir any new veiitiiics, hut the dillieiilly was obviated by liie
jrenerous aelioii ol' Mv. .Mc(,>iies1eii, wjio oll'ereil tlie ico'^'hs then in tlie
warelioiise to oiil lit ail who eare(l lo make a 1 rial in tlie new district.
Kii,dily men i^' ik advantage of liis olTer and, iiroeeeding down Iho
river, built .■abinsat 11 ])oiiit on tlie Yukon 12 miles above the preseut
site of iiie loun, called tlio settlement Circle City, from ils pi'oxiinity
to the Ar<'t^' t'lrcje, and wintered there. During lh(> ico jam in tiie
breakin;,- iin il the river thai sprin.u; the ponded water overllovved its
banks and swept away a few cabins: so, warned by this accidoiil. tlie
inhabitants moved farther down the river to a little hi,gher grouiul
and built the new town of Circle City in ils i)re.sent situathm at the
head of tlu' \'iikoii I'"lals.
In the early spring the pro.spei.'lors had ero.ssed the old Indian trail
over ^Medicine Lake to the head of Hireh Creek, had discovered and
staked claims on .Mastodon, Ilog'em, .Miller, Greenhorn, and Inde-
pendence creeks. It was soon seen that Birch Creek was a paying
district, and that there was room fora large number of miners; conse-
(piently almost all of the newcomers went to the new camp; the
hranches and gulches of liirch Creek were traveled by prospectors,
and Circle City became the most important settlement in the interior.
In tlie Fortymile district the best producer was .still INIiller Creek;
Franklin Guleh and Xapul'eon Creek were making good yields; Glacier
KA.
OUUIlllll II.]
IIISTOKY ANI> rONHITIiiN
119
EQUENT
bi'cods wlio
k, i'(']»n'ti'(l
i' news was
ininci's t(i
to i'oti'iii\ ('
iii'V to Itiiy
itlMl hy llic
tlieii ill tlie
}\y (lislrict.
• Idwii llic
I he present
i pi'oxiiniiy
jiliii ill the
I'llowed its
eiiloiit. the
lior ffroiiiid
liim at llie
ndiiin trail
(voi'eii aiKJ
, and Iiid(>-
8 a payina'
ers; coiiso-
canip; the
rospeetors,
le interior,
llor Ci-eeic;
d.s: GliU'ioi'
_\(".
Cri'ok was bidding fair to i-iiiia! Miller; (ioiil and liedroek <'reoi\s liad
also l)een prospeetcii lint pronouneed uiisatisl'actory, and the liai'^ on
the main ereelv and tile river, wliile not by any means worked mil.
liad I'aiii'ii olT in proihietion. In the nieantinie the Koviikiik was
bein;^ prospected to some exteiil, anil ><.!ii,iu)o worth of aold is said to
have been taken out and shipped Irom Taiiana Hading I'ost.al the
moiitli of the 'I'anana l{i\er.
The toial aiiioiiiil i)rodneed l)y the \'iikon jilaeersiii ls;i( wasiloiiliie
that of the year bel'ore. and was divided lietweeii the two lai^'er dis-
tricts as follows:
Forlyinile $4(Mi,0()0
Uireii Creek '••.i"""
Total 40'.i.(M)0
With the iioUi from the placers was broujiht out >i-Uiii.:iii in silver.
Ill IS'.).") ihe output had donble<l a^raiii. Hirch t'reek discoveries on
]\!asl(nloii, .Miller, and Ilo^r'em creeks wi-re payinjr well. Kaj;le ('r<'ek
was opened up and work bt!jrun, showing; tlie prettiest pdd on the
^'ukoii. Harrison ("riM'k was jirospected from eiicl to end diiiini;' the
winli'r. and a little prosix'ctiiijj; was also done on Porcupine ( reek,
whei-ea result of lo cents lo tlie pan was obtained. Ui'aver (reek.
which Hows inlo the ^'iikoii 1 ">0 miles below Circle ( ity, was examined,
and a few men look out some ijold from I'reacher Creek.
The center of the niiniiif; po|)ulation had by this time been trans-
ferred from Fortyniile to Ciivle City; for, as estimated by the stalis-
tieian at San Francisco, the population of Fortymili' was <io(i; of
Circle City, "uO. jiirch Creek had also become the more important
producer, although the older creeks on Fortyniile were paying well.
MISSION' CREEK.
Aliout this time gold was discovered about 70 miles below T'orty-
niile Post, in the drainage area of Mission t'reek (so called because
an old mission is located .just aiiove its mouth). .Mission Creek is a
considerable stream flowing in a general easterly direction; -2 mih.'s
from its mouth .Vmerican Creek conies in from the south, and it is iii)oii
the latter ('reek that all the claims are located. At- the time of visit
there were -5 men at work 12 miles from the mouth.
Oufput of the Yukon /iliifers in lSt>5.
Population.
Distrii-t.
Fortyniile. ..
Birch Creek..
Koynkuk . . .
Beaver Creek
Total ..
Product.
120 (iEOLOUY OF THE YUKON GOLD DISTRICT, AI.ASKA.
All .It Ikt placers in xViaska, outside of tli»^ Yukou, produced in 1895
^(ilt.iiS'.),o4.
MYXOOK CREEK.
One i)f tho Intost (lov(>loi)iii"nts is .Myii()(»k Creek, s j called from its
discoverer, Jolui Myiniok. It is situated iu the Lower liainparts, 00
tu7i» miles above the month of the Taiiana. Tts()rij,'inal Indian name
is Klanai-kakal, meaiiiii}," •' creek suital)le for small boats," and so it
apiMJirs on t!!(> older maps of the rejjion. Inasmuch, however, as the
names In com,non use by tiie miners and traders of the country are
certain to supersede liiose iriven bv the natives, wo have used tlie
latter nomenclature in all cases. The c.ctk rises in the hiirh moun-
tains I'oiininfj the Tanana divide, and Hows in a general northward
direction. Four miles from its Junction with the Yukon comes in
lliinti'i- t'rei'k, ;iO miles loiii;-, wliieh rises near the liead of .Alynook
'v'reei< proper, ami Hows liist north, then bends westward around
tile lie.id of Little .Mynook, another branch of the main creek. Still
another lar.i;e branch, about :.'() miles loiijj;, enters from the south-
west, 10 miles above Little .^lynook. On the riiited States Coast
and (T(>odetie Survey imip the name Wliymper River, jfiven by
Schwatka to the stream ne.Kt north of Klanarkakat appears, 'i'lie
native name is Vukiitchkakat, meanin}; " biji; shallow creek," but
later it has m)uw to be known by the name of Mike Hess Creek, or
Hess Kiver, in honc>r of a. pioiu-er miner, who <lid much for the devel-
opment of the country, died in 18!t2, and is buried at Fortymile.
He.ss River, then, and Mynook Creek, are probably the streams
referred to above as havinj^ been prospected l)y the S.'liielllin lii'oth-
ers as early as 1882.
Late in the spring of 1803 John Mynook, a half breed, prospecte<l
on Myuook, Hess, and Tanana waters, and found coarse gold. About
the same time (). V. Miller prospi.'cteil Hess Creek and did a little
iiiininu' in a gulch near its head, but it was not until the s])ring of 18'.i(i
that active mining was begun. Several claims were located at that
time, and work was beguu ou two of theiu.
.Myiu)ok Creek is the only one in the country upon which Indian
labor is employed, for it is the general experience tliat the Indian is
not worth much as a miner or prospector. He lacks the perseverance
and steadfa.stuess of |)iirpose which sustains the white man under
dillicultiesand reverses; even when succc.ssftd he has not the necessary
ambition; a^d however willing he may be. as .soon as he gels a little
moiu-y he will stop work and spei.d liis entire fortune, with no thought
of to-nu)rrow. Kor this reason, t mrefore, having becJi tried in dif-
ferent parts of the c»aintry, Indians hiive been given ni) as unreliable.
On Mynook Creek an Indian staked out a claim last spring, but was
not allowed to hold it, on the ground that it is illegal for a nalivo to
own mining land. As far as we were able to observe, the Indians
HISTORY AND CONUITI< N.
121
y'«
Imrc in( ill will t'pwiinl llic iisiii'ihts. but nilliiT took it ;is a niaiici' of
ooiii's(> that tlic wliilc man should lake possession.
Tn ]8'.t.")-'.n') iiiiifh new jiroiiml was pi'ospi'ctt'd in the l,o\V(>r Hani-
jiarts. Myiiook and othcl•^s, having oxaniincd tho lloss Kivcr coiiiitrv
and tho Tanana waters, report, d fine fjold on all the streams that
liead ill the Tanana hills, hut Utile coarse frold. ^> eonts per pan being
about the best iirospeet. On the K(;yii;;uk there were several men
who stayed on until the summer. Another party ol' three men started
from Circle City in the late winter, crossed the mountains near the
head of Crooked Creek, reaehed the Tanana :>ii(i miles frr)m its mouth,
and haviiiir built boats, lloaleti down to the Yukon. Alon^' the way
they prospected side si reams and irulclies, bill found nothinir miieli.
CONIHTUIN MF FdKTYMU.K DISTIilCT.
The eondilion of tlie Forlyniile district in the summer of IS'.Hi was
no! so piod as formerly. Ii looks very much as if i( had seen lis best
davs. and unless several new creeks are discovered it will lose its old
posilion. Chicken Cicek, discovered in the siu-inir of ]X'.n'>. caused a
sensation foratim-', bi.i in the end more men left Fortymile tlian
came into it duriiiji' the summer. John :\Iuller"s biff strike uudoubt-
edh served to retain claim owners on Miller Creek, but, on the whole,
Ihe e\odiis to .\merican Creid.' and the liirch Creek diirixiiiL^s was
verv iioiicealilc. On (ilacicr and (iohl creeks about H") men were
workiiii:. 'I'Ik' <listrict was particularly unfortunate in Ihe long
droii.yhl which lasted for six weeks. In almost all of Hie jrulehes there
was not enoui:h water to run the sluices, and Ite- men were forced to
idleness. For bar \.!>rkiiif; a low stage of water is Ihe most favor-
able, but, as has been said before, the bais are nearly worked out,
very b'w yieldini;- over *S a day, whicli, at I lie iirev.Mliuii- prices, would
entail a loss. In all tlicre are probalily :!•'> men at work on the bars.
rOMHTTdN OK BIKCH CREEK DISTUICT.
In the summer of ISlHi llie liirch Creek district. |)artly owing to
tin' fact thai on ihe whole lower river considerable rain fell during Ihe
spring iiid summer, was in a tlourishing eondilion, and formed a con-
trast to that of Fin'tymilo. ^Nlost of Ihe gulches were running, miners
were working on double shifts, night and day, and many huge iirolits
were reported. On Maslodon Creek over :iOO miners were at work,
many of them e.Kpecting lo winter in the gulch. Thiity-si.\ claims of
500 feet front were being w<trked, the most important being the Dis-
covery, one-half mile fnmi the moulli, where I'li men were shoveling
in, in double shifts.
But while Mas odon, one of the lirst -discovered ereek.s, lias hereto-
fore been the lest [iroducer. it islhought that Ihe conipara.lively new
creeKs, E;;gle and Harrison, will in a shnt lime become more inijior-
12-
(;i:(
)HKJV OF THE YUKON GOLD DISTRICT, ALASKA.
tJiiit. Frciin time Id tiiiic, lno, new creeks are discovered in tliis dis-
fri.'l, liie latest heiii^- Carter or iiutte Creeii, wliich is one of tlio
tributaries of the main l'.ircli <fe .<. It rises about 10 miles southeast
of Mastodon 1)( , ami is in to l."i miles in lenf,'tli. The first rumors
started ;iO men across the mountains in Au^nist, \SW, and they staked
most of its lentrtli: but. aceordiiiir to one man who returned to Harri-
son after the first rush, its ricliiu'ss lias l)ei'n greatly exa,i,^j;erated.
l'l'0|>(isl:ii llYliUMl.ICKlNd.
On Mammoth Creek little work has been done. A short distanee
below the mouth of Mastodon, on the rii,dit-hand side, the pay has
been followed under a h(>avy deplh of jfravel, I)ut the breadth of the
valley lower down prevents its location. Bars hn\- he: cashed
for Hold on the -ueanders of this creek, and ^4 to •< ■ ■ .'.de.
With the slow method of rockiuir and the existins infj;!; iiriee of the
necessities of life, tiiis return woul'. not be \, .'ilable, i)utit is thought
that iiMieh of the frround now too jioor to work mijfhf jjive fro,id
returns uitii the use of soni(Muetlu)d of wholesale strii)ping au'l wasli-
inu'. S f ,:■> miners have jdanned to work this and othei' good
trround which is supposed to exist uudei' the dee|> eoverinirof moss
an<l gi'avl in the wide valley of .Mammoth and Crooked ci'eeks by
hydrauliekin^. the waterto be obtained by tappin;;' Milleror Mastodon
Ci'cek near the hea.l. They realize, however, that ifi will 1)(> several
years before their sclieme can l)e put into I'peration, because at |)res-
ent both of tlie gulches art- [)ayiiijj: well, and they will continue to do
so foi' the ne\t live yeai's at least. About that time the placer claims
will be worked out. and it is thouKlit that then owners will have no
objection to any usa^i' of the water.
Tlicre are several disad\antaji<'s whiidi may render this scheme
im nacticable. First and foremost is tiie hiffli cost of all the necessary
implements and materials. Au;aiii, it has been foun<l by expei'ieii o
til, It a constant su|)[)ly of wafer is necessary to the success (
liy<lraulic operations, and in this retrion the amount is far from eon
slant. l''or almost eiirlif inoiitlis in flie year it is nothinj;, am for
a |» viod from the middle of .May to the iniddh* of June, the .sea.scn of
floods attendant ii|ion the melting of ice, it is at a hiax'miim that
somel iiiies causes ineoiiveiiience. l''roiii .lune until the freeziiiu;, late
ill Septemix'i', the amount is variable, generally diininisliinu jiradii-
ally, and late in the summer there is little running wafer in simi(> of
the sfulches. One of the I'esults of the ineonsfancy of the water sup-
])ly would be the daniaginji- of the fhimes. for boxes that are full at
one time and empty at aiiot tier soon ;;o to pieces i'l' snow is not
deep, nor is thei'i' iiiucli winil, so that the daniaj,je >. >' ftingc.ui l".'
disrejjarded; however, that by freezing would be eonsideralile. Two
oflu'r factors, ire to be eonsidiu'ed — the head fall of fhestreai". and the
jiossibiliiy of disiiosing of the t'liliiigs. To calculate the first exaotly
requires an accurafe f ;)))ograpliic survey and a series of levels from
OOODBKH.]
HISTORY AND (.(INDrriON.
123
the ,-cs("rv()ir1(> tlic outlet. We have not made sudi a siirvfx . ,iii.l cur
aii.Toi.l elevations nuist be taken merely as an aiiitroxiniatiun f. tlie
truth. From them, however, we would say that there is available ;iii
800-foot fall in 8 nules on eith.'r Miller or Mastodon, or loo f,.ei tc tiie
mile, taking as a starting pointthe jiiirliest |)osition in whieli a d.iin
restrainin.u- any quantity or constaney of watereould be built. Sueii a
head of water would fjive suffieieut i)ressiir<-. aniountiiif;. as it clors,
to somethiu},' over 000 pounds per square ineh, for in hydrauliekinn
in ('alif(U'nia often only 100 to 4.50 pounds per square inch arc usc.I.
A^^ reu.-rds the disposition of tailin.irs, there isapparently no icason
why they could not lie run olT into Crooked C're(di. 'I'his stream lias
considerable volume and v^■lo(•ityat the mouth of .Mammolh, and fr..ni
this point to its mouth there is an avenge grade of :J7 fe.M per mile,
sntlieient to carry off an immense amount of refus(\
It has been erroneously stated in one of tiie late mint rejjorts that
hvdraulickini; with small hose has been employed in several localities.
At no district visited by us was there a hose in use, nor could we
learn of there ever having been any. The miner's inii>lcMients are
always the simplest, consisting generally of a hand gnld pan. spade,
whiiisaw, anda.x. These, with his blankets, provisions, and cn(uigh
money for a year ahead, constitute the stmi total of his cai)ital. In
fact, it is a well-worn saying that .Mask.i. is 'M poor man's country,"
almost no cajjital having been invested up to this time; hut if this
plaM slhiuld be successfully carried llirough, llie ai)iilicat ion of
liydraulics to other i)ortionsof the country would give the industry
of placei' nuuing greater i>ernuinence and stability.
TFII". fl'I'KH VtKON.
<;n the Upper Yukon and on Lewes itiver. t<"r.itory properly out of
the scope of this report, the old rock i)iles and a few ruined cabins
a' sli!l to be seen on the site oi the Cassiar Bar excitement, but all
the bar workings are desei'ted, the gulch diggings lower down being
more attract ive.
At tin' nioiith of Stewart liiver a few miners were in camp prepara-
tory to a trip 111) ili*^' ''i^'^'""- " '^ Ihought that Stewart Hiver has not
licen given •< fair 'liance -ince the lir.st year i^\' the exeilcment.
Ju.sl at the lim.Mvhen good gulches might have been <liscoveivd came
the reports from Fortymi'e. which drew all the miiu>rs away. It is
kno,Mi thai for JOO m.;v:.from the mouth the bars contain quantities
of gold, ami ftu' this reason it is the general oi)inion of the miners
that more wystematic prospecting should be doiu' along both branches
of this stream. It is very probable, indeed, that many i)arties will
winter there this year for that puriHKse.
Kl.dNIHKK I>1STKI('T.
The latest e.Kcilement in the country <iccurreit during the latter part
of August, is'.ii;, when it was reporle(l at Forlymile thai lich placers
124 (,;;;;L()(;y of the yukon got,d district, ai.aska.
hiul Ikh'ii (lis('u\('rc(l iijioii t ho wdtors of Klondike River. Kloiiilike,
a miiit'r's coniipt inn of ihc Indian uaiiio 'riir'oiidiiik ('" wmIci' full of
lisli"). cnlcis the ^iikoi, 4.J niilcs Ixdow the nioiilli of Sixlyniilc and
I.") alxivc tile old Fort Keiianfi'. Cpon t ho Coast Survi'j' chart it is
{;i\ I'M as iicindoci' Hivor, l)nt no ono oxcepl Schwatka. who christened
i) ill IS,s;i, has ever known it hy that name. On a l)ar at its nioutli
was located an Indian lishi'ij; villaj,'e of ]it>rhai)s 100 population during
the salmon .season, for. as il.s name sif^iiifies, it has lon^' been a. favorite
tishin;; fTround for the Indians, hut until late years it ha.s not been
nvaded liy the miners. Willi the annoinicemenl of jrold there was a
.enuiiie stampede to the new reirion. so that, wiii'e in the winter of
18it()-'.»7, Fortymile was almost deserted, it is estimated that 3.")0 men
spent the winter on the Klondike, in the s'ulclies, and at the new lown
of Dawson, established on the banks of the ^'iikon at its mouth.
Jlessrs. Harper and .losejih I.adiie. tia<lers at Fort Selkirk and Sixty-
mile, are the founders of the new camp, which is ex])ected to rival
the oldrr selllcinenls.
The district I iroperly includes Kloiidiki'Rix'er. with its main branch,
I5(in.iii/.a. which is -Ji miles long and ciiieis the Klondike :i miles from
its mouth: Hunker Creek, (lowiiii; into the main creek not far from
the mouth; and the drainage of Indian Creek (native. "Sugachuk ").
Kettlcsons Folk rises in a mountain tlivide opposite the liea;", of
r>o!ian/a Creek ami Hows into t,)uartz Creek, which is described as
being a very long branch of Indian Creek. At h^a.st 10 miles below
Kettle.sons Fork, Phil Creek <'omes in from th<' east, and still farther
down, perhaps 4 miles, the main Indian (reek is met with, and ."> miles
upthis isCiiltus Creek. I!ut the more important parts of the di.sirict
ai'c. at present, upon lionanza and Hunker creeks. Cpon the former
thedi.scovery was made, and >il.O00was taken out in Angtist and Sep-
tember, ISIk;. Since that time, according to 'ast inforiMution, 400
claims had been loeate<l to .laniiary. 18117. and .ibou; half as many
upon Hunker I'reek, and the indications at the time of writing are
tliat there will be a great increase in iiopulation in 18it7-!)S. But
there appea-s to be plenty of room for many more [irosjiectors and
miners, for.ilthough it is dilhcidt to state the area of the new field
from data at hand, it is not far wrong to say that gulche.s and creeks
which have shown good prospects are spread over an area of 700
si|iiare miles.
.Vn estimate of the gold production for 1S!m;. which appealed in the
Alaska .Mining Record for .(aniiary, 18!i7 (Juneau. Alaska: editor,
(4. H. Swiiieliart ). follows:
.l/r(.s'AY( MiiiiiKj RrranlS v.ttimntr nf Ahiskai, ,j<il,l i»'<»luctioii in JSIitS.
BirchCrcek.. Sl.iiOO.OOO
Other districts. „0(, qq,,
,„ ,,'''"'"' - '-MOO.OOO
All otlieriilacers (lutside of the Yukon . 21.5,000
Cook Inlet placers, included in the last 175' oqq
•Ui'.,
:;4
1
)ODi.icH.l HISTORY AND CONDITION.
Oui- own cstiiuate is also here given:
Aiifliiir.t' I'ntiiiiiili' of Ahiskiiii (jiild pnuliictiDn in I'irifi.
District. Poinilati.iii. Output.
Fort ymile - '^
Americau Creek — 35
BirchCreek -• «00
Mynook Creek .. . ''■'
Koynkwlc River | '-'>
Other districts ' "•">
Total 1-7'iO
12o
I
$460,000 ]
l.").()00 I
OOO.OOO I
10. 000
5. 01"!
10. 000
1,400,000
While iniu'li iiioro conservative than the former, this, too. is irreatly
in excess of the figures given by the Director i>f the Tnited Stales
M iiit , for several reasons. One is, that %I,-iO(J,(XK3 represents not only
the i)roduct of Alaska proper, but the added output of Mritish ereeks;
another is, that, while the figures given below are compiled from the
returns of bullion which has found its way to market, our ligures
e.\pre.ss the amount actually turned out.
The estimate furnished by Charles G. Yale, statistician at San Fran-
cisco, is as follows :
Charh'i (i. Vale's I'ntimaie of Alaskan <jolil j)ro<liictioii in ts:'€.
BirchCreek - .^nOd.WO
Othercreeks Jt^iUWO
Yukon River total .. .- 8(K».000
Cook Inlet placers ... -- liO.OOO
Total production of Alaska. - 2. S61. 30fi. (il
This last total has been further corrected by the Director of the
Mint to *J,UU,L'(j:j.
DIFFICULTIES OF DEVELOI'.MEXT.
ThedifBculties in the way of speedy development of the country are
many. First and foremost is the climate— the short summer sea.son,
during Avhieh work can be done, and the long, cold winters. The ice
breaks up in the interior al>out the middle of ^Fay, and by the 1st of
June, the flood season having passed, the miners are at work. Winter
cones on again about the last of September; the grouml freezes, the
crteksand rivers stop running, and underold methods very little work
could bo done. At present, however, in ; great number <pf gulches,
especially where the gravel is deei) and timber iilentiful, the i)rocess
of minnig by burning and drifting is employed to advantage. The
frozen ground is thawed by fires l)uilt upon the surface, shafts are
sunk until the pay streak is struck, when the rich gravel is taken out
and laid by until the spring.
n
■ IK
l-_>(i OKOLOGY OF THE YUKON GOLD DISTRICT, ALASKA.
l'ni>|iccl(MS have also found it navantat?eoii8 to make their search
f(U' favorable localities at tlie time when the frozen ground ren-
ders travelinf; through tlie swampy, moss-eovered eountry easier,
and for !his reason, more and more every year, prospeeting is done
in the winter. Tlio elainis are tlius loeated and the! miner is ready
to lu'triii work with the; lirst spring thaw. Krosts are frequent during
the summer, and it is slated that in tlie winter tlie temperature
has often fallen as low as —70' V. in the vieinity of Fortymile. It
is easily seen, therefore, that, in spite of the riehness of the soil,
the Vukoii district can with ditliculty heeomoan imiwrtant vt ,etal)le-
producing country. Root crops have l)ccn tried with encouraging
results in many localities, especially at Fort Selkirk, where last year
potatoes of a pound weight wens raised. A small garden near Cone
Hill on Fortymile Ch-eek also produced a good crop of cabbages and
turnii)s, and at missions on the lower river turnips of great size were
seen. However, there is always an uncertainty in the crop. To
insure it against freezing it must be blanlceted many nights during
the year, and in this eountry the hi},di price of even the < omnuniest,
cheajiest kind of drilling pn-cludes the protecting of areas large
enough to i)roduee crops sullieient to sustain even tlii-j small popula-
tion through the long winter.
The introduction of beeves has been trie<l on a small scale, but it
is a (|Ueslion whether great nunUiers could be provided for. In the
swamps about Circle City grass grows to the height of 3 or 4 feet in
summer time and makes excellent hay. All other feed must come
in by way of the mouth of the river, and in .small (iiiantities at that.
It is seen, tlierefore, that whatever Alaska may be in the future it
is not now self-supporting from an agricultural point of view. .Moose?,
caribou, and hare vaiy in ((uantity, one year abounding, and again
disappearing from i' region for twelve months at a time.
The high cost of living has been referred to before. Hivause of the
great distance which all supplies must, be brought (over t.niMi miles
by ocean and river) and on account of the risk involv(>d in carry-
ing such great distani'es and in such dangerous seas, even the com-
monest necessity of life sells at the point of delivery at a price that
would seem ridiculously high in the States and which is maintained
at the highest [loint by the almost entire absence of eoiniietition in
trade. As a sliglit compensation the rale of wages is much higher
than in any other jiart of llic continent, «l(i a day being llie general
wages, and in some of the more remote gulches «Il' a day of ten hours.
In winter the juice for labor is ijo to ijiS per day of six hours. Hut
this comiieiisation is only [larlial, foi' often the delivery of provisions
isd( layeil by some accident, and llie miners, entirely deiiendent upon
the outside world 4.00(1 miles away, must either leave tlie coiiiilry or
must slop working long enough to replcnisli their stock of jirovisioiis
by hunting. The loss from thiscau.se is often api<reciable. Many
:1
OIPIiDRlCn.)
HISTORY AND CONDITION.
I J 7
'I
tiincs tlu> minors lia\(' Ix'Oii at llic poiiil nt' slai'valinii, and tlicro is
liardly a winter wlicii they arc not put on rations so nian>' |ioiiii(ls of
bacon and so niucii tlonr to the num.
Tin? ainio.st entire liiek of division of lal)or is al.so detrinicntal to
projrrcss. .\t ])roscnt a man innsl not only l)e ndncr, hut lioii.se-
linildcr, carpenter, and cook. To a jjreat cxtenti this is iluo to the
ab.seiice of invested capital, which has been allinled to above, but it is
beint; remedied by the imniitj;ratiun of labi)rers attracted by the high
wujjes of the country.
(iOVKRN.MKNT.
Many
MIXKHS MKK.TINO.
The 'miners' me(>iinj.' is the oidy fi:overnmont in the interior of
Alaska, but it api>ears nearly to havcoutlived its nsefuliit'ss, and with
the ffrowth of Ihi^ count i-y and the introduction of a class of noiipro-
dnciiiii; adventurers, attraetoil by the hope of makinj; fortunes at tho
expense of the producers, it is fast boconiiiifj; a mockery. The better
class of miiuM's have already objected to having; disputes occurrinir
in the ji;ulchcs settlcnl in town, for tho jfreater i)rei)onderaiice of the
disreputable class in the latter makes it alnntst impossible to obtain
Justice there. Again, v.''ile i)erfectly wtdl intentioned, the minei\s
ar(> often in)t the ones l)est fitted to decide cases iini)artially.
Tho j)owers of the miners' mcotinu; are threefold — letrislativc, .judi-
cial, anil executive. \o provision is made for a gmcrning olliccr, the
whole fabi'ic resting on the great American principle, "majority
rules." I'nivorsal sulfrage is given, and all have an cipial vote. The
method of proceilure is as follows: If a man has a gricvjiiicc. he jjosts
a notice to that effect; and calls a meeting for a certain date. At the
appointed time the miners of the locality assemlile, generally in the
open air, i'.nd a moderator from their number is appointe<l. Then the
prosecutor presents his case; the defendant answers. There is cross-
(|Ucsti((niiig, s])eechcs pro and con ai-e made, and in the end someone
puts a motion, which is either carried or defcate(l. If carried, the pen-
alty is iin|)osed without delay. As e\|n-essed l)y one who thought he
had been wroiigeil b,\ oiii' of these meetings. "Tlie man who |)uts his
motion liisl wins." However, sometimes tiow, antl gcin.'rally in the
early days, tho decisions liave been remarkable for their rigorous
justness. Some of the peinilties arc: h'or stealing, banishment from
the country, h^ven if it is the dead of winter, the culprit is given
enough i)rovisioiis and |>ut on a sledge ami started on his way. In
somejiartsof the counti'y the additional punishment of whipping at,
the post is inllicted. Stealing has Immmi remarkably infre(|ucnl. I'or
Ihri'atening with wca|)oiis the punishment is the same. There have
been no murders in the country, but for the offense death by hanging
i.s the iHMialty provided. (Gambling is a legitimate ainuseineut, and
has no i>lace iu the catahigue of luisdeiueanors.
128 GEOLOGY OF THE YUKON G01,D DISTKICT, ALASKA.
MINIXi; LAWS.
Tlio iiiitiiiif,' laws as establishctl l)y llu' iniiu'is are sliKlit'lj- different
fri)ni tliosi" iif the United States or Canada; in fact, thoy dilTer for
dilT.'reiit ^'iijclu's. (Jciiorally llie flaiiii is 500 feet for gulch diggings,
fi 1 riinrock to rMurock, l)iit in some gulches that do not pay well
enough with small diggings an clToH is being made to stake claims l,:i-'<>
feet long. On the otherliand, creeks which arc becoming crowded are
staked :ioO feet to the claim. No one man is allowed to stake more
than oticM'laiiii in his own name, with the exception of the di.scoverer,
who is allowed l.ooo feet instead of 500. If more than one miner made
the discovery, still only the amount of an extra claim is given to the
discovery <'laim.
The oTilyolViccr in the republic of miners is the recorder (one in
each gulch or creek), who is appointed by popular vote. He is wit hout
executive power.s, his duties coii.si.sting in recording the names of
claimantsand the locations of their claims, for which he receives a fee
estalilished for the particular gulch in whi<'h he holds oflicc. The
amouiii generally received is *l' for every claim registered, although
in some localities it is as high 'isSS. Sales of claims are also recorded
with this officer, who collects a fee therefor, but here his duties end,
or, -ather, beyond this point they are not well deliiied. It has been
maintained by some that he has the right to rel'use to record claims
if, ill his .jiulgment, to record tlicm would work inju.stice to another
claimant, while others say that the power of deciding the question of
owner'ship between dilferent jiarties belongs entii'ely to the minors'
nu'cting. In the latter case it is obviously the duty of the recordei' to
iid'ormthe prospective victim of a claim-jumping scheme; neverthe-
less, he must make a record of all notices of occupancy.
The law proviiles that for the month of July the nuner must do
"asse.ssuMMit work," as it is called, and failing this, the claim is once
more thrown on the market. In case a miner is prevented from doing
this work himself, his title may be held good by proxy. So it happens
very often, when a nuui goes out of tlie country foi' the winter, that
he hires somemanto takehis place (mthe claim during the assessment
month.
These are the placer laws as applied in the American territory.
Those which are beginning to be enforced on the British side of the
line and are crowding out the ones formulated by the miners are
the regulations already in force in other parts of Caiuida and British
Columbia. The laws governing quartz claims in all parts of the Ter-
I'itory are the same as the (luartz-t.iining laws in the States.
It will be seen that we have here a .society in the first stages of
formation. Up to this tinu' th(> people have governed themselves
ami have done so veiT well, but there will come a time, and it is not
so far distant, when the need for better government will be felt.
iiiKiDHlrll,]
HISTOKY AM) CONDITION.
129
Y different
ditTcr for
I (ligj;iii!,'s,
t pay well
aim8l,32(»
owded are
take more
liscoverer,
liiitM' made
veu to 1 he
er (one in
is wiliioiit
names of
eives a fee
fl'-ee. The
I, altiiouyh
ioroeorded
luties end,
[t lias been
ord claims
to another
liiestion of
lie miners'
recorder to
; neverthe-
er must do
[lim is once
from doing
it happens
rinter, that
assessment
1 territory,
side of the
miners are
and British
of the Ter-
s.
t stages of
themselves
nd it is not
ill be felt.
Canada lias iippre<'ial<'d this need, and has stationed a garrison at
Fort C'lidaliy to maintain law and <irder in lier teiritoiy. On llie
Aineriean side the miners still frame flieir own laws. Two customs
iiis[)ectoi's ai'c stalioiwd at Circle City, but tliey ai'c the only rep-
resentatives of the I'liited States in the interior. Willi closer con-
nection with the homo (Jovernment, tlirough some ci\il or inililary
representative, the better jirotection would liave an important eco-
nomic elTeet.
I'Ol'l'KATKl.V.
The inhabitants of the Yukon district and Alaskii may he divided
into three classes: I'Mrst, the natives: .second, the cmjiloyccs <if the
two tradin;; com ■ nics, and third, the miners. With tlic (irst and
second classes we have little to do, since our interest is mainly in tlio
prodiu'crs of gold: nor shall we attempt to make any estimate of the
number of people now onga.i;ed in mining along the coast. .According
to IJishop r»oiiipa.ss, in charge of the Church of Kiigland missions in
the Yukon district for the last t weiity-eiglit years, the Imlian popula-
tion of ^Vlaskaisnot over 10,000. Th:' Indianssubsist by hunting and
lishing, and are only .just beginning to learn the value of the |trccious
metals. The members of the two companies which trade with the
natives and furnish supplies to the miners in the gold districts
number in the neighborhood of L'OO.
The other .-lass, the miners, is of a transient character, including
but few who intend to stay all their li\es in the country: in fai't,
it may be said that every man exiiccts to return to civilization sooner
or later. Of those who do stay from one year to the ne.xt it is nearly
impossible to tnakean estimate, on account of their wandering habits,
which lead them .sometimes hundreds of miles from the niiningcanips,
so that they may not be heard from for many montlis. Again, the
nuning camps now established are not by any means stable. One
year the center of population may be at one point, and the next,
because of some rumor of rich finds, it is transferred to an entirely
new region.
Xor can an exact estimate be made of the number of men that come
in every year, for of those who cross the Chilkoot Pass and float down
tlie river a lai'ge number stop at Fortynuh- Post only long enough to
exchange greetings with those on shore. It may be that they stay also
a few days in Circle City. They then either float down to ,Sl. Michael
in small boats or take the river boat out of the country.
It is impossible, therefore, to make anytlung more than a rough
estimate of the number of miners who are comiiaratively fixed, and it
should be borne in mind that even in a few days the distribution may
be entirely changed. The table on page 1132 shows tlio number of
workers from year to year, and an attempt lias been made to distin-
guish between those w-intering in the British territory and those on
the United States side of the boundary line.
18 UEOL, PT 3 9
^
130 tii;Ol,O0V Ol- TIIK YUKON (iul.l) DISTKICT, ALASKA.
I'lidDICTION.
Tn <M.iiiiiiliiiir IIh- slalislics irivfii Im-1..\v (p, |;L'), tli<' cstiiiiati-s of tlio
pniducl of Kolil Mini silver of Aliiskii aii<l tli.' output of tho Yukon
placers jrivfii in tlie annual r.-porlsof I lie Direetorof llieriiiteil States
.Mint liave been followed, exeepl where otiierwise slated. Tliese are
based on the amount of iioU\ turned in at the mint at San I'nuK'iHeo,
which amoiinl is paieil with the returns from smelters and refiners
all over the i-ountiy: so that in the case of oriraiiized eoiii|iaiiies, such
astheTreadwell mini Doiijrlas Island and other la r}j;e corporations,
the slated output is very nearly correct.
Itut in the case of the Yukon placers several factors modify thci
accuracy of tl lint returns. Some of the miners u|ion reliirninj,'
from the irold (ields |ilace their j,'old in the mint directly or with the
reliners who make reluins to tlie San Franci.sco mint; others, liow-
e\cr, ;,'o Kast or South, and their ^'old is not turned in for .sonii lime.
A^rain, it is slated that a certain amount of bullion, i>robal)ly very
lar),'e, is sliipiicd abroad direct without ever lieiii}; deposited in any
mint in tlie I'liited States. Fiirlherniorc, niiicli gold remains in
Alaska for many years after its production. Taking all these facts
into consideration, we think it conservative to ad<l one-third of the
total as given in the table in order to complete the actual itroduction
of the Yukon placers iiii to 1897.
The cori'ccted figures will then be ap]iroximalely *i;J,()ii7,Si;j for all
Alaska, and •^:!,:!lii,.")( il for the Yukon jilacers. These figures repre-
sent the product o*' Alaska alone, and do not inelude that from
gulches, creeks, and bars in IJriti.sh territoiy.
In the first part of the table, from the year 1880 to 18SG, a small
part of the ])roiluction of the Yukon was from American soil, liiit no
returns having been made, I have considered the total as having
come from the Northwest Territory.
From 1880 to 188.'! the Yukon output altogether was unimportant;
but with the discoveries upon Stewart Hiver in the latter j'ear
(although, as has been said above, placers had been worked on the
Hig Salmon River prior to that) production really began, and .since
then the growth has continued from year to year with scarcely any
falling ofT.
With tlie discovery of Fortymile in 188(), Alaska began to be impor-
tant, and the production was about evenly divided between the two
countries. For the next four years there amy have been a slight
decrease, although, from information derived from miners who were
in the country at that time, I have made tho estimates for 1887, 1888,
and 188!) about the .same. I'nfortunatcly, however, the data are not
very accurate for this period. In tho report of the Director of the
Mint for 1888 no estimate of the Yukon output was given. In 188'J tho
88(5, a small_
soil, but no
1 as haviiij?
iiimportant;
latter year
irked on the
1, and since
icarcely any
to be impor-
een the two
Ben a slight
rs who were
r 1887, 1888,
data are not
eetor of the
In 1889 the
KA.
OuoliKRH.)
HISTORY AND CONDITION.
131
latcs of the
the Yukon
litod Stat(!S
Tlirsc are
I''i'an('is('o,
iiid rcliucrs
lanies, sucli
irporations,
inodil'y the
1 I'clurning
or with the
thcrs, how-
soiiK time.
)l)ably very
ited in any
remains in
tlu.'se facts
liird of the
production
7,8i;Uorall
iures re])re-
' that from
statistician at San Francisco says, in the annual rei»ort, tiial the [iro-
duction of all mines in the Territory, outside of l)ouf;las Island and
Juneau, was iii;!()n,(M)0. No estimate of the Yukon placers appears,
but in the n^port of the governor of Alaska for that year, including
also ISHH, it is said that "several parties have returned fi'oni the
Yukon placer liclds, who report limited results, owing to floods, high
water, stress of weather, and various accidents." One of the acci-
dents referred to here was jjHibably the delay of the river boat in
reaching Fortymile with jirovisions. 'I'he men in the diggings were
starved out, and in tlio first week in October, l8Sii, there was a gen-
eral e.vodus down the river. Nearly a hundred men left the ])ost in
small boats, some going all the way down to St. Michael at tlie
mouth, others stopping and wintering at Indian camps or trading
posts on the way, wherever food was plentiful. Foi'tunateiy the river
did not freeze as early as usual that winter, so that there was little
actual suffering in the trip, although the journey on tlie lower river
was made in running ice. This winter ot 1881»-'.t0, known in the annals
of the country as "starvation winter," had the effect of reducing the
product by reducing the number of producers, and this reduction was
felt mainly in the spring of 1890, before the population, decreased by
the exodus of the preceding fall, had been replenished by new arrivals.
Since 1890 the increase in production has been rapid, doubling
neai'ly every year the production of the year before. In the report
for 189-t Birch Creek showed as a producer for the lirst time. Its
output was not great, only $9,000, but in 1895 it almost equaled that
of Fortymile, and in 1890 it far exceeded it.
132 GKOl.OOY OK THE VlKoN (iOlD IMSTHICT, ALASKA.
I'riiiliictiiin «f ijnhl iiikI .lilin- in Ald.Hkii.
Yfiir.
PriHltlrtinll
ot |i(jl<l.
ll
?E
Produttiun
of HilVtT.
1^
— a
a r
"" s
r
Amount i»f
ontput from
Yukon pliici-rH,
nil Kolil. 1
Per
ci'ntof
Kol.l
friim
till' Yu
kon in
Alu»ka.
NuintxT
of Yukon
miniTa.
1S8I. . -
.•«;H,()iH)
I)
80.00
$0.00
(?)
18S1
ir).o(K»
14
144. 30
1.5
0.00 1
(?)
ISM'^.
l.jO.dOO
13
0.00
12
Small, i
50
ISW!....
:too.(Ki(i
0.(10
10
((l.O(K).OO
,50
188-1 ...
200. 0(H)
111
0. 00
U
Unknown.
I.)
188.-). ..
282. (K)0
9
2,000.00
•1
11
i(25.0oO.O(
75
188(1 ...
•1 «>. (100
9
2,000.00
14
11
;< 7.5, 8,58,
200
1887....
a::,, 000
9
300.00
11
r C30.000.
1 30,000.00
)
f
I
200
50
1888
8.-)0. 000
8
3, 000. 00
10
9
J- 40.000.00
I 35, 000. 00
1 *
f
I
100
1.50
1880....
900,000
9
10,843.00
14
11
f 35, 000. 00
*■ 40,000.00
^
{
1.50
135
IHiHI.
Ttl2, M(\
9
9,097.00
14
11
50, 000. 00
7
{
1.50
1.50
1801 ...
900, 000
10
10,343.00
14
11
100,000.00
11
{
200
1.50
180'>....
1,000.000
9
10, 343. 00
14
11
110,000.00
11
f
1
225
175
180:t....
1,010,100
9
10,800.00
14
11 ' 200,000.00
30
{
500
200
1894 ...
1,113, .wo
9
28, 783. 00
13
11 i 400,000.00
i
37
1
400
GOO
189")....
1.01.5,300
7
86,880.00
13
9
709,000.00
44
{
600
800
180(1. .-
Total.
CorVfd
2,014,203
4.5,708.72
800,000.00
SO
;
700
1,000
12,240,313
827, .500
13, 067, 813
320,491.03
d3,483, 000. 00 ' 1
827,500.00
1
1
i 1
1
i 3,310,500.00 1 35..
II II
(I E. R. Siidmorp.
hU, M. Diiwson. , , , ., ,
rill brai'keted tlKure.s the upper set refers to British territory; tliu lower to Alaska.
(/ Total output from American territory only since 18NI.
For the purpose of eoinpnrison we }?ivo the table of tlio production
of Uritish Cohiinhia from 1S.58 to 18I»5, takeu from the AnuiJal Report
of the Minister of Mines, 1895:
^KA.
msTOHY AND (ONDITIOX.
133
Output <if ijdld mill sllivr III' llrtiuli < 'uliiiiiliiii l'rii"i /> T.v /,, /\,'i
OP
tof
>
uintx'i-
lid
of Yukon j
<HI1
lUilRTS. 1
Yu
n ill
ska.
(?)
(?)
5(1
50
■iOII
■i
f
I
::'0()
50
4
{
100
150
4
/
150
L
135
7 (
150
i^
150
iJr
200
L
150
11 (
jl
225
175
20 {
500
200
ST 1
400
1
000
"(
600
800
39 '1
700
1,000
35
\'J_
1
Year.
to Alaska.
> production
uUal Report
18.58...
18511...
1860...
1861...
18<i3...
lMt!;l...
1N64..,
1865...
|X6ti. .
1H67...
1868...
1860...
1870...
1871...
1872...
1873...
1874..
1875...
1876...
1877..
1878...
1870...
1880...
1881...
1882..
1883.
1884.
1885.
1.S86.
1887.
1888.
1889.
1890.
1891 .
1893.
1893.
1864.
1895.
Total
Oold anil allvur,
total.
NuniluT of
minem.
YIbUI iht
IIIHII.
,<l520. :)."i;i
:i (too
.'i!173
1,615.072
4,oo(t ;
4o:i
2, 228, .547
4.100 '
506
2,666,119
1.200
6:i4
4,246,266
1 4.100
I 4, 4(M)
517
482
3, 735, 851
4,4(M)
W9
3,491,205
4,294
!»l:i
2.063,107
2. 982
891!
. 180,868
3,044
814
2,372,972
2. .390
092
1.774.179
2, 369
749
1.336.9.-16
3.348
569
1.799.44(1
2, 4.50
734
1,010,792
2,»(K)
671
1,37.5,409
2, 3(K)
567
1,814,619
2, .868
043
3.474,904
2.(»24
1,322
1,786,648
2. 282
783
1 , 608, 181
1.960
820
1,27.5,204
1 . 88:i
677
1,290,0.59
2. 124
607
1,013,827
1 . 9.55
518
1,016,737
1,898
.551
054, 085
1,738
54.><
794, 252
1,965
404
735, 965
1,858
39(1
713, 738
2.902
246
903, 652
3. 147
287
694,709
2, 342
296
616,731
2.007
307
636. 79(i
1.929
830
56.8,419
1.343
423
439.811
1,199
3.58
399, 526
1,340
298
379, .535
1,247
3(W
! 464.. -.66
1,610
283
036. .545
2, 030
313
5.5.11.5,965
■■■HP
C U A V T K K T T .
Tire (;kc>j.()(;u'AL <'oi.i'MN'.
THE BASAL GRANITE.
Tlic . ^lost rciek foniifUion louiid in ilio Yukon fiold dislricf, is
graiiilo. Only in (lie Korlymilc district lias this rock been studit'd
in any detail; for in Ili<' otlicr itold-niinini; districts which wore cjirc-
fiilly examined it does nut appear to be exposed , and ui the rej^ions
which were more hastily passed over there was not suHicient oppor-
tunity to separate it clearly from other ^rnK-'o which occurs in the
same areas, but which is clearly y()un,!>"r and of in<rusi\e origin.
On the ]\liller Creek trail, which leads from Fortymilo Creek to the
diggings on ]\Iiller and Glacier creeks, there \s exposed, nearly mid-
way between the eiulsoi the trail, a zone of granite about miles wide,
"his rock is sometimes massive, but us'.ially lias a gneissie or S(!histoso
structure, and oecasionallj- is altered into mica-schists; tl'.o less altered
portions, when fresh, are of a gray color and contain porphyriti(! crys-
tals of feldspar, Avhich in tlio more schistose zones become lenticular
bodies or eyes. In tlie sliglitly weathei'cd lock the color changes to a
red or bi'own, wliich is cluM'act eristic of most surface outcrops. (Quartz
veins, generally of liiiiitetl length, < of the nature of gash veins, are
frequent; they usually conform in strike and dip to the schistose
.structure of the granite.
MICROSCOl'IC DKSCIUI'TION'.
I^ntler the microscope tlie rock shows the original liypidionio.,,hic
granular structure of granite, but tiiis has Ih-cii much defaced by
crushing. l''rom the elTects of this crushing the brittle ininerals are
broken and elongated, and the Ih'xible minerals, such as .iiica, are
bent. The component minerals are essentially (|uarl/,, ortho(d'isi',
with frequent microclineand some plagioelase, and biol ite, all cotirseiy
crystalline. The felds]i!!" fre(|iiently occurs in large jierfei t pheno-
ery.sts; the biotite is comparatively fresh, the orthoch'..se kaolinized
nnii museovitized. Accessory minerals are sometimes fou;.d in large
amouni, r.otably muscovite, calcite. epidote, garnet, micaceous hema-
tite, kaolin, pyrite, and chlorite. S(niie of these minerals are derived
from the decomposition of the feldspar and mica of th(> granite, while
others, such as the garnet, re[)resent const riiclive processes attendant
upon the development of the schistose structure. Since the rock h.is
thus evidently been subjected ii, great shearing and alteration, bring-
ing about the formutiou of now minerals, if niav bi> called a schist; yet
134
t UBR.]
TIIK IIASAI, (iRANIIE.
135
(lislrict. is
•un stiulit'd
wore oiU'c-
tlu' rcirioiis
icilt (»])[)< •!■-
nws in llio
origin,
'reek 1o tlio
learly niid-
niiles wide,
nrsclii.stosei
less altered
yrilit! crys-
u lenticular
Iianges to a
)s, (gnarly,
I veins, are
sehistose
dionio.jdiie
ilet'aced hy
linerals are
s .nieii, aro
ortlioel'ise,
allcKiirsely
fiM t iiiieno-
kaoiliii/.ed
i: <i in hwiio
'I'liiis lieiiia-
are dcrivcil
anite. \vliil<>
s attendant
he rock has
iIIdii, liring-
isehist; yet
;i
the jiranitie strneture is usually (luite uninislakable in tiie li"l<l. and
invariably under the niicroseope, so tliat the term " iirauite-schisl"
is most a|)[)ropriate.
MiK OF THE KOKTVMll.K (.KANITE.
This };ranite-s<'liist has h(>en spoken of as occupyin;? a lielt several
miles wide nn ilie Miller Creek trail lietweeii Fortyniile ami Sixty-
mile creeks. On Ixitli sides of this licit arc sciiists whicli ai'c in part
micaceous or hoi-id)lcndic, and often pass into less common vaiiclics,
but wliich are, in most eases, made up chiefly of (|uart/.; and study,
bolh in the ticld and under the microscope, nuikes it clear that they
a (■ altered ([uartzitcs. These (|uart/il(^-schists. as we may call them,
arc identical in api)carance on both sides of tiu; j^ranitc licit. On the
side toward Fortyniile t'reek tlicyare continuous from tln-i;ranite
licit nearly to the main ereek, when they jiass into a formation wliicii
is made uii very larjrely of marble; on the side toward S'xtymile
(reek a narrower band has been examined which is made up entirely
of ((uartzite-sehists. Throughout this whole cross-section from Forty-
mile to Sixlymile t'reek the schistose .(tructure strikes nearly uni-
forndy east and west. In passing from the (puirtzite-schist to the
marble on Fortymilc (feck one observes that the two rocks are at
first finely iutcrbe<lded, and that tlien the marble increases in quan-
tity s<i as to form vc'-}' thick beds with bands of schist between, which
have been derived from (piartzite and other detrital rocks.
The alt(>rnation of riuartzite and marble in small bands jrives the
true beddiiif; of the series, esiiecially since this is often found in
places where the forces prodiicin};; the schistosity have acted very
little and can not have changed the original order. The niicro.scope,
moreover, shows (luartzite passing into marble through all transitional
stages, a I'ommon I'ock being a calcareous or (loloiiiiti(! qiiartzite in
which are zones of calcite or dolomite inclosing ([uartz grains. This
alternation of marlde and (iuartzit(\ giving \\w true attitude of the
beds, conf<irnis eractly in strike and dip to the schistose structure of
tin ([Uartzite; therefore the movement ]ir(idiicing schistosity seems to
have operated in jilanes mostly jiarallel to the original li<'ildingof the
s<'dimentary series. Along Fortynile Creek from Moose Crecdc to
the lorks the structure is general... plainly discernible by means of
the alternation of marble and ■ lartzitc; these show that the creek
(lows parallel with the strike of tlie formations keeping generally in
the marbles close to their contact with the massive (|uartzite-scliists.
The beds ha\(' a general east-west strike, and, although in places
much contort e<; into minor folds, have a very marked general northerly
dip. averaging I'd or 4u . TJie series of imerbeddccl inarblcs, ([uartz-
ilzes, and schists of various kinds will be called the P'ortymile series,
while the (luartzite-schists lying between the Fortymilc series and
the granite will be called the Mircli Creek scries, on account of their
being .so well sIkiwii in the Uirch Creek district.
^^^^^
136 C.EOLOGY OF TIIK YUKON (lOI.D rJISTRICT, ALASKA.
From 111.- .ir.'iicial iitliiu.le i.f tlic l)c<is, wlii(;li we liavc iiotcilas hav-
iiifr liccii aMMMlaiiifil from llic inliM-lx'd.ltMl riiiarlzito ami marbles
aloiif; F.irlymilr (rcrk from Moos.' <'rc<'k lo 11i(> Forks, it will bo soeu
thai 111.' Mill.'r Crock trail is a crDss-sooti.iii, ciittiiij,' very noarly at
ri;;hl aii;;l('s to the forinaf ions. From the attitude of the marbles and
iiilerlM'dd.'d .iiu.rtzil.'s on ^foose Creek, it f.)llows that the quartzite-
sfhists of Hi.' Kiich Creek formation underlie the nnirble beds of the
Fortymile format i.m. It has also been sli.iwn that at the contact of
these two fornmlions the actual attitude of the rock conforms to tlio
schist. )se structure of the .luartzite, so that the schistose structure of
the qnartzile represents at that jilace the true beddinj?. Between the
Fortymile formation and the sheared jiranile zone the strike and dip
of the schistose i)lanes in the quartzite remain the same, so that the
frranit.' has th.' appearance of un.h'rlying the quartzit>^-sehists. On
the south side of the !j;ranite, li.)\vever, the qnartzito-schists, while
havin;;a p'lieral east-west strike, like that of tlie same f.irmation on
the other sid.' of the K""">ili' belt, have a general dip to the south
instead of to the north as b.-f.ire. This dip is comparatively flat,
avera.iriiiir between HI" and -20". The east-west strike and the south-
erly dip are practically uniform, excei)t wliere distuvl)ed by minor
folds. If the schist. isily in the (|uartzile-schist on botli sides of tlu»
jrranit.' belt is parall.d with the original ])lanes of sedimentation, as
lias been shown lo be the case on Fortymile Creek where a test can
be applied, Mien th.- northerly dip of the <iuartzite-si'hists on the
Fortymile Ciuek side and the southerly dii> of those near Sixty mile
Cii'ck in.licate an anticlinal fold.
iii'sidi's till' -Miller Creek trail cross-s.'.'tion, another section across
tlie jfcncral strike of 'he beds is afford. 'd iilonj; the Soiilli Fork of
Forlyiiiilc Creek, between its, junction with the North l'^>rk, and thv
count ryaroun.l F'ranklin Gulch and Chicken ('reek. This section is,
howev.'r, not so satisfactory, for there is a ;j;r.'at am. )iinti of intrusive
rocks, which have distorted and altered the sedimentary schists so
that the {fciieral structuri' is often tl.iubtfiil, and even the nature .»f
the si'liistos(> ro.'k is notr always clear. Xe;ir tlie Forks, however, the
frcn.'ial dip .if 'he beds, as b.'fore, seems to b.' to the north. Tlu'se
bc.ls are the ii,,irbl.'S ami .(Uartzites of the Fortymile formation.
Soiitli.if the Folks there is a broad b.dt in which the inti'Usive rocks
are so abundant ami cause such .list urban. ■(> and alteration that tlie
slrucliire of 111.' .s.'dimeiitai'y rocks is uncertain. On the s.iuth side
of this bi'll are marbles with inler.'alatcd siliceous schists, which liave
as before, a frcneral east-wesi strike, but. a uniform .southerly dip,
so that they pass down under youiifrer ro.-ks.
Tlu'sc Iw.i cross-se.'ti.ins establish the existence of an anticlinal
fold rtith an east-west axis parallel to I''ortymile Creek between Moose
Cre.k and llii' Forks. The section on lhi> South Fork c.impared with
that of Miller Creek trail shows a closing oi the fold toward the west,
i^^-
CA.
Till-; HASAI< (iRAXriE.
137
I'll as hav-
1 marbles
ill 1)0 SOPH
nearly at
arhles and
quartzite-
kmIs (if the
contaci of
•nis to tlie
met u re of
(tween tlie
ko and dip
■<() that the
liisls. On
ists, while
mat ion on
the south
lively flat,
the soiilh-
Ity minor
des of the
ntation, as
a test ean
sts on the
■ Sixtyuiile
t ion across
h Fork of
■k, and tht>
seetlon is,
f intrusive
schists so
' )iatiir(> of
)\vevcr, the
Ih. 'I'iiese
formation,
isive rocks
m that th(>
south side
vliich have
herly diit,
antieliinil
cen .Moose
pared with
I the west,
for liere the distance between corresponding format ions across t tu' fi dd
is niueli less than in the other cross-section, as is shown on the map,
PI. XL\'II, p. :!1.S. In this section the (plartzite appears to lie contined
to a narrow zone and to form the summit of the anticline, no sheared
granite belt having be(>n observed, although the many ilikcs ami the
coi.seiiuent metamorphism make tl;c matter doubtful witliout more
St udy.
As far as can be seen, however, the contact o granite withtlie sedi-
mentary schists roughly correspondsin ont''/ie with tli(> strike of ine.se
sell ists and with tli(> contact of tho(piartzite-.schists with the overlying
marli'es of the Fortymile formation. This granite therefore has the
fonu .if outcrop characteristic of a rock lyingstratigrapliically lieiieath
the sedimentary schists. On the .Miller Creek trail no intrusive phe-
nomena were noted near the contact of granite with other rocks, but
oi. ac<'ount of the schistoslty of Ixith format ions such iiheuomena miglit
eisily be ob.scured.
The possibility still exists, therefore, that the granite may be intru-
sive, having broken through the scilimcntai'v rocks in a massive
body and dragged up the Itecls so iliat tliey lie on its flanks, dipjiing
away ill all directions. Throughout the gold district there are largo
quantities of granite which have cut through rocks in this fashion, as
is abundantly proved by the contact i>lieiionieiia. At the same tiiii(>,
these jilaiiily intrusive granites are m iliii.irily massivi' and have no
schistose sti'iiclure, being, therefore, Liii-i- iliaiithe ili^i iirl)anc(> which
brought about this structure MJiih- the granite lying along the axia
of the Fortymile anticline iiarkedly scliistose and can not he
rclerred to the sam(> jieriod. Anolhei' theoretifal consideration is in
regard to the naliire of the rocks whii'li lie ..n ImiiIi sides of the sch >-
tose graiiili' of Fortymile Creek. TIicm liisls, as has 1 n said,
are beds of altered quartzite, and the plainly ib iriial grain^ .f which
they are coiiiiio.sed are chiefly quart/.. In .some i use--, howe\ir, otlier
materials are present; rounded grains of feldspar arc fouml. ln.ili
orthoclasc and plagioclase, containing sometimes flakes of biotiie iind
graiiisof e])idole; di'trital grains of zircon, a|)at it e, and iii,i_'netii. have
also been observed. 'JMiesi' minerals must necessarily hi \e come from
the deiiiidat loll of .some older rock, and their nal un> suggests deriv-
ation from granite. It may therefore bi concluded that ilie I'orty-
mile granite is older than the schisto.se .sedimeiilaries aid n I'lies
them.
KXTKXT 111' Till'. (iUANirK AKKA.
As stated, this granite occurs along the axis of a fold whose trend
corresponds in a general way with the sehistosity. This same east-
west trend of schislosily is found nearly uniformly in the schists from
Fortymile Crtck along the Yukon to near the junction of the I.ewes
niid I'elly, and throughout this distance belt.s of granite alternato
138 GKOI.OGy OK THE YUKON' GOLD DISTRICT, ALASKA.
with hells of schist (•orrcspomliii!; to tlif JJiirh Creek fuid Fortyinile
foniiiitions. 'I'licre is f'o miK'li intrusive ;:raiiite, but this is solid
and coniimiiitively ffesii, wiiile tlie l)asal ^M'anite is altered and schis-
tose. A speeinieu of tiiis seliistose granite collected by ;>[r. Ogilvie
on the Yukon near the mouth of the Stewart Hiver is described by
.Mr. F. 1). Adam.s.' under the head of "Qiiartzoso biotite-jfueiss."
This jiianilc l)ecouies more aliiindant to the soulli, so tliat, Fortymile
(reek seems to he on tlie northeri. l)oi'der of tlie area in whicli it
a|i|i«-ars. Dr. ('. W. Mayes- notes that tiie iirevailinj; rock of the
greater i)art of tlie re;;ion lietweeu the Yukon and the St. Klias Moun-
tains, aloiii: the Wliiti' Uiver, is a reddi.sh >,n-aiiite, ([uito free from
hornhlende. and fre(|uenlly containin.g lar^'e porpliyritic crystals of
feldspar. This red j,'raiiite hejiidfris to he Arcliean, and let be tlio
Moor on w liicii 'aU'r .sedimentary rocks have ])een deposited. Granite
also apjiears to co\e|-a very lary:e area alonjr tiie Tanana I{iver.
.Vccordiiig to Lieu'. II. D.Allen,' " the hanks of the I 'pper Tanana,
wiiere there is rock, arc f;<'nerally eompo.sed of a yellowisii j;ranite,
fast underj^oiiig disintegration, as evidenced by tiie inuumerai>lc par-
ticles of mica sus|)ended in the river and the ever shifting cjuick-
sands." l'ros|)ector's who have ci-ossed fi'om the Hirch Creek d'stri'.t
over In the 'I'anana also report, that the rock along a considerable part
of itr- ii'ule is granite, although it may he renuirkcd that their sepa-
ratioi. of graidte from other rocks is by no means accurate; and fr<nn
other mci; it has been leai'ued that a prominent mountain aliove the
headwaters of Sixtymile Creek, called Sixtymile IJutte, is of granite.
'J'his same hell of granite has l)een shown by the ()l)serv.'itions of
Dr. G. "SI. Dawson^ to e.vtond in asoutheast direction from the Yukon,
wheie it lias jtlready been noted, along the I'elly, where it has lieen
found at various places, and to he I'oughly continuou '. iis far as the
r)(>aso ]{iver, a short distance below Dea.se l,ak(>. The total lengthof
this northwest-soiitheasl granitic belt from Dease Hiver to the locali-
ties where it has been ri ported on the 'I'anana is not far from 8(M)
miles in a straight line, 'i'lie observations made during tlio last sea-
son, however, sho\\ that this belt probably does not .-ross the Yukon
below its great bend at the Lower Uamiiarls, for although granites are
foiiml at this )ioint they appear to be intrusive and younger.
The schists which ovei'lie the basal gi'aiiite are found continuously
ahmg the northeast side of l he granite belt in the Yukon di.strict of
Alaska, being exjiosed notably in the Fortymile and Hireh Creek
mining districts. On the iionheast this licit of schists passes under
successively younger rocks, so tliat in a short distance there 's a con-
tinuous licit of Tertiary strata running parallel with the schists. In
' Am,. Ri'pt. (Iciil. Niit. Hist. Survi-y riimi' new kitIcs, Vi>1. Ill, Pnrt I. p. ';.I1IB.
'Kxii.Mlitii.il tliiouuli till. Vnlf.iii itistri.'t: Nit. ()i'..i,' Mau., V.il. IV, ji. l;i!i.
"xpi'ilitii.ii t.. tlio CiipinT. Tiiimim. ami K..yiikuk rivfrs: Si'iiHti' Due.. 'V^"ll^.llin^ttllIl. 1H87, p.
1.111.
'Ann lii'pl. Oiul. Xat. Hist. Survey (ana. la. l.s-T K.'-, new seriw. Vol. Ill, Part 1, p. MB.
srnm.]
THE BASAL GRANITE.
139
British territory Dr. Dawson' lias not oil tlie o'oso as-sooiation of tho
jrranilc Ix'lt with jrncissic rooks and hornblondo- ;inil luioa-sohisls,
wliioli, from his ilos riptions, are probably idi'ntioal with tho .-i.-liistoso
rooks already mentioned. On the sonth side of tho u:ranito bolt,
alon;,' the AVhite Kiver, Dr. llayes^ found marbios and .s(<hists lyiiij;
ti])on the jrranite, whioh are evidently similar to tho sohists of the
I'.iroh Crook and Vortymilo series. Farther .south Dr. Ilayos fouiul
that those sehistspass under youn,iJrer rocks of Carboniferous, Triassic,
and Cretaceous age; and above tliese again lie still younger rocks,
which Tiiay be Tertiary, possibly corresponding in part with the Ter-
tiary beds noted a short distance farther east by Prof. I. C. Husscll '.
The position of tho rooks on both sides of the granitic bolt, which is
such that successive younger formations occur as tho distance from
the granite increa.ses, both on the northeast and on the southwest,
evidently points to an anticlinal ridge of such vast diinonsions that it
could not have arisen from any h>cal cause, but must have originated
ill the main crust of the earth; it may be called, therefore, the Yukon
goaiiticline. Following the general trend of this geanticiinal ridge, as
shown by observations on the Felly, Yukon, and Tanaiia, it will be
seen to cut the Yukon at tho Lower Haiuparts. At tiiis jioiiit, how-
ever, as already noted, the basal granite does not appear, although
the sedimentary schists which overlie it are prosoiit The width of
tlu schists is niuoh lessened in comparison with thai at otlior jioints
farther southeast along the bolt, and this narrowing, witli tin- absence
of granite, indicates that the fold has chised consideralily.
If the geanticline persists beyond this point in a northwo.st direction,
the basal granite and associated schi.sts should cross the Koyukuk.
Concerning this river very little is known. Lieutenant Allen,' how-
ever, reports that the country draino<l by it is oomiiosfd of rocks
similar to the Tertiary strata on the lower Yukon, and what vague
ie])ortsaro brought out by prospectors .seem tocontiriii this statement.
If tliis is true, fiio northwestern extension of the Yukon geanticline
diiiiiniahes rapidly near tho point where it cuts the Yukon at the
Lower Ramparts, till the younger Tertiary strata, which lie on its
Hanks, approach from both sides, and finally meet, cutting olf the
uorthwostern o.Kleiisioii of the schistose formations.
lU
1
HZ
1^
t'OlJKEl-ATIO.V.
Concerning the ago of thisliasal granite, wo may term it. by analogy
Willi fundamental granites in other regions, Archean. This is the
iiaino given it by Dr. Hayes,'' and Dr. (i. M. Dawson" points out tlio
' dp lit.. 11. atB.
'Op. fit., p. 140.
'Bull, V. S. (li'nl. Survi'y No. X4 : Curri'lntiim Pnpi'rs. Nforene. p. 2.W
•Kxpi'ditiim to tho Cupper, Tiinuim. uml Kiiyiikiik rivers. Si'imtc I)".-,. WiisliiiiBton. 1-*k7,
I>, I.V..
lip. fit. p. i:tn *
"Op. eit., p. ii")B.
^♦^
140 GKOl.OGV or THE YUKON GOLD DISTRICT, ALASKA.
groat -Ago of tlio granites of tliis bolt as ooniparod with tlio intnisivo
graiiitos of tlio Coast IJaiigos, and roniarks the roseniblanco to tlio
pi'olmlilo Archoan gi-anites in the tJold Uangcs in southern British
Columbia.
THE BIRCH CREEK SERIES.
Lying on both sides of the bolt of sheared granite which oeeuiiios a
posit ion between Fortyiiiilo and Sixlyniile eroeks is a series of schists
of nearly unifcn'ui ai)i)earan<'o. This granite has been do.scribod as
being probably the fiindaiiiontal rock in the region, and as forming
in the Fortyniilo district the axis of an anticlinal ridge. The schists
which lie on Ixtth sides are therefore younger than the granite ami
older than the other roek formations, which will bo described later.
GENERAL CHARACTERISTICS.
Conqmsilinn of /'of/r.s.— Those schists are of a general light-gray
color and are chiefly made up of quartz, though hieally they pass into
darker and even graphitic varieties. The typical rock is a (piartzite,
of which the grain is often coarse enough to bo distinguished in the
hand speeinien, and of whose dctrital origin the inicro.scoi)o leaves no
doubt. In the less-sheared portions the quartzite is hard and white,
and shows very little the eflfeots of pressure; usually, however, a
decided scliistosity has been produced, evidenced ))y parallel cracks
and shear-planes, along which nietaniorphic minerals have been
developed. In the move intensely sheared portions tlie planes of
scliistosity are sot closely together, and the rock appears to bi; niailo
up largely of mica; buti even in such rocks the microscope ordinarily
shows that the ("hiof constituent is (luartz. From these typ(»s, which
are derived from the alteration of quartzite, there are local gradations
into schists, which are plainly derived from finer .siliceous and car-
bonaceous .sediments. These schists are met with in small amounts
at various points in the series, but especially in its lower portions.
There are also found, although rather sparingly, schists of igneous
origin, being dikes which have intru<'ie(l into the sedinientai'y .series
previous to the shearing. In some i)lacos the contact between this
igneous schist and the sedimentary (luarlzite-schist was seen, jiroving
its dike-like nature. So far as noted, these intrusions were of granite
in its various phases, although the original structure of the rock has
often lieen obscured by the subso(|Uont motamorphism.
Dikes of various kinds, later than the development of schistositj',
are also fre([uent.
CorrisponiJrnrr of Hchistnsi/i/ anil strafificntioii. — The planes of
sehistosily have boon descril)o<l as pntbably conforming, in a general
way at least, to the actual stratification of the rock, for in the Forty-
mile district the scliistosity dips away from the underlying granite
on both sides of the anticlinal axis and dips down under the overlying
infi-iisivo
lice t(t tlio
?iii IJrilisli
<)c'('U]ti('s a
s of scliists
scribed as
IS foi-miiifj
'lie scliists
raiiitc and
(I later.
li.ulit-pray
y i)ass into
(|iiartzito,
IumI in the
» loaves no
and while,
lowever, a
llel cracks
liave been
planes of
o be made
ordinarily
pes, wliieli
fjji'adalions
s and car-
11 aiiiouiits
r portions.
»f ifineoiis
taiy series
tween this
n, jirovinfj;
of fjranite
rock has
i'hi.stositj-,
pianos of
a general
the Forty-
iK Kfanito
ovorlyiiifi;
KIM'mi.]
THE IMKCH CKKKK SERIES.
in
¥
€
#
marble and schist formation which is exposed on Fortyiiule ("reek;
and in the Hirch I'leek district, whore the same rocks are exposed, the
conditions seem to be tlio same, since the dip of tlie schistosity in tho
(inartzite-sehisls carries them down below the inarhle anil schist for-
nialion which is reported by prospectors as lyin;; to the soiilii of tlio
tfold-beariii}; district. It is in the Hircli ("reek district that this series,
composed of <iuartzite-scliists, is shown to the best advaiitap-, and
thoroforo to these rocks may conveiiic iy be given the name " IJircli
Crock series." To tho overlying series, consisting of marbles with
intorbedded <iiiartzite-schi.sts and garnet iferous, micaceous, and liorn-
blendie schists the name " Fortymile series" will Ik- given, on account
of their being so well exposed along tho cauyou-liko valley of this
stream.
The parallelism of tho schistosity planes with tho original bedding
on Fortymile Creek is lurther shown by the close correspondence of
the strike of tho schistosity with the lineof contact between the Uirch
Crock and Fortymile formations and with tho strike of the alter-
nating beds of marble and (luartzito-schist, which plainly .show tho
original stratification. In attempting to estimate the thickness of
the Birch Crook series of schists on Fortymile Creek, moreover, the
planes of schistosity were taken as representing the actual bedding,
and from this datum and from the known width of the belt occui)ied
by the rocks of this series in the Fortymile district the calculation
was made. In the Hirch Creek district the same method was applied,
and hero the dip of the schistosity was gi'oatly dilTorent from that in
the Fortymile district, as was also tho width of the bolt of tho Birch
Creek series; yet the total thickness of tho series was computed to
be very nearly tho same in both districts. This of it.self is strong evi-
dence for regarding the .schistosity as nearlj- approaching the original
bedding.
Quartz veins. — Another distinctive feature of the schi.sts of the
Bivch Crook series, and one of {^n-at economic importance, is the
occurrence of ipiartz veins in nearly every rock exposure. 3Iost of
these veins are small and nonpersistetit. 7"hoy lie typically parallel
with tho schistosity, although occasioiiallj' ;hey cut across it at vary-
ing angles; and most of them have plainly boon affected l)y the same
dynamic disturbances which have produced tho scliLstoso structure in
the inclosing rock, lor they have been bent, broken, .shredded, and
fractured, both megascopically and microscopically. There are also
other veins, wiiich are later than the shearing. These veins are tho
chief source of the gold throughout tho district, and occasionally show
free gold in the crevices of tho (piartz. Pyrlto is very abundant and
galena not infrequent. Pyrite and galena are also sometimes found
impregnating the more .schistose portions of the rocks without abun-
dant gangiie material.
Summanj. — The Birch Creek series may then be summed iii» as con-
142 GEOLOGY OF THE YUKON GOLD DISTRICT, ALASKA.
sistinj,' mostly of (luarlzite-schists, grailiiiK into finer-grained, often
}rrai)liitic scliists. All these rocks eontaiu dikes, and <iuart/ Yeins
carryin},' },'okl and various metallic minerals. The .slipping in the
rocks eonsotiuent upon the pressure which produced the development
of metamorphic minerals seems tohave followed in a general way th<>
original bedding planes, so that liie planes of schistosily maybe takcu
guardedly as indicating the true attitude of the beds.
DISTRIBUTIDX OF BIRCH t'REEK SCHIST.
The liirch Creek series, as already delined. is apparently shown in
its entire thickness in the Fortymile district. Above Fortyniilc
Creek, on the Vukon, this same series outcrops for a large part of the
distance nearly to the junction of the Lewes and the Pelly. Along
this line the sheared quartzites contain belts of granite, .some of which
is schistose and very likely belongs to the fundamental granite, while
in other places it is fresh and massive and .shows plainly an intrusive
character. There are also occasional belts of marble belonging to the
Fortymile series. Tlie schistosity in all these rocks has a general
east-we.st trend or strike, and the alternating bands of diflerent rocks
appeal' to follow this same trend. Judging from the attitude of tlioir
schistosity, these rocks are con.siderably but not intensely folded, and
their thickness must be very great, since a uniform strike and dip are
maintained for long distances without any great change in the nature
(if the rock. Specimens of schists collected about 10 miles above the
mouth of the AVhite Kiver, on the Yukon, and about 25 miles below
Sixtymile Creek, on the same river, Avliicli liave been examined
microscopically, are essentially schistose (piartzites, containing grains
of zircon and a variable amount of muscovite and biotite, formed in
consequence of shearing.
Below Fortynule Creek the Birch Creek formation was not encoun-
tered until the u])peri)art of Birch Creek was reached, where theseries
is found to the exclusion of other rocks. The strike and dip of this
series in the Bircli Creek district are consistent at different points.
Tlio general strike is nearly east and west, changing in the western
Iiart of the area, in which active mining is carried on, to northwest,
and in the eastern part to northeast. The dip is almost invariably
to the .south at a comparatively gentle angle, ranging between 5°
and ;50°, and perhaps hardly averaging more tlian 10°. The nearly
senucireular course of the strike shows a broad, gentle fold, and
since the dip is uniforndy to the south, it is natural to suppo.se
that in this direction the Bircli Creek series passes under the Forty-
mile series. In fact, the existence of much marble has been reported
by a i)rospector at some distance farther south, on the southern side
of the divide l)etween the Birch Creek waters and those of a tributary
of the Tanana. This information, however, is not necessarily accu-
rate. Clilfs of white rock, apparently dipping northward, were also
s
SPfllR.]
THE BIKCH CRKKK SEUIES.
143
■J
1
scon "11 till' south side of llio Crazy .Moiiiilaiiis, hftwccii Circlf City
and the Uirch Creek f,'ul('li('(s. Awonlin^' to a pn.sii.'cloi-. IIk'sc clilTs
aroot' iiiarhlf. Owinjj; to tlic very jrentle (li|)of the sfiics in the llireli
Creek district, it liore occupies a broaih-r belt tiian at any otlier point
examined.
ISeiow Cirek' City tlic Uirdi Creek series was not cMeoiiiitereil on
tlie Yukon until a point was reached just above llie nioutliof the
Tanana, where a scliistose, cah-arcous (luartzite, earryinu(iuartz veins,
was found outcro|)pin^'. Froiu tliis point it outcrops freciuently aloiijr
the river nearly to tiie nioutii of the Nowikakat, allliouixh it is fre-
quently concealed by the overlyinfi con^donierates and sandstones of
the Tertiary, and by the sills and ehiys of the Pleistocene.
Alon^' the rijrht '.tank of the Yukon, between the inoutli of the
Tanana and that of the Xowikakat, is a ranye of low mountains run-
ning,' parallel with tlie river. On these mountains the bare rock
seems to be lijjht blni.sh-!j;ray in color, and although the structure of
the mountains is nuissive, structural planes seem to be visible. The
fact that the outcrops along the river at the base of tlies<' mountains
arc for a long distance of mieac^'ous and garnetiferous (luartzitc-
schists, h'nds probability to the belief that the mountains themselves
are composed of schists belonging to the IJirch Creek formation, or to
the Fortymile fornuition, which is also cut by the Yuk<»n above the
Tanana. This lower belt of Hireli Creek rocks, running parallel with
the Yukon below the Tanana, has exactly the .same characteristics as
tlie rocks in the Fortymile and Birch Creek districts. It has the
same rock types, the same schistose structure, and the same ([uartz
veins which have ordinarily been sheared with the inclosing rock.
The series here also contains gold, and abotiti the mouth of the 'I'ozi-
kakat a large sheared vein of quartz, carrying gold, has been worked
a little l)y Mr. G. C. Bettles, the trader in charge of the post at
Tanana.
THICKNESS OK THE HIKCH C'KEEK SERIES.
From the area which the Birch Creek rocks occupy between the
Pelly Hiver and Fortymile Creek it is clear that their thickness must
be very great, even if much folding is assumed. In the Fortymile
district a cross-section was obtained alon;, the Miller Creek trail,
where the .series forms a belt about .S miles in width. Along this ))elt
the dip of the schistosity was observed at numei'oiis points, being on
an average about 4U^, which was also the dip of the intercalated
marbles and quartzite-schists of the overlying Fortymile series on
Fortymile Creek. Inasmuch as the dip is nniformly to the north,
there seems to have been no great amount of minor folding, and the .S
miles of oiitcroj) witli an average dip of 40^ gives a total thickness of
about i5,()U() feet.
In the Birch Creek district, as already stated, the dip is much
IM
(il.OI.OUV OF TIIK YIKON G01,U l)If*TKICT, AI.ASKA.
slij;lili'i, iivcrjij;iiitr ixTliaps in tliu iiciirlilinrlidod of lii . 'I'lic widtli
of llii' Im'Ii ill which Ihi- scries outcrops, however, is iii.iieli greater
iis niciisiired from tlie iiioiiiitaiiis Just north of tlie IJireli Creek
fruiches ill a southerly direct ion to llic h)cali1y where iiiarbk" lias
Im'cii reported by |)rospeetors. This is iirohalily Uw. total width over
which the series crops with a iiiiiforiii tlip; for iiortli of tlio I'.ireli
Creek fiiilches, on tlietrail to Circle City, schists similar tollioseili
the Forlymile formation arc found cropping, and fra^'nlellts of mar-
Ide ill the coarse snivels; and marbh' is said to outcrop on the north-
ern eiiil of the rid^'e of mountains lyiiii,' Just west of IJirch Creek.
'I'lic semicin'iiiar curve in tlie strike of the Jlircli Creek (iiiartzites, as
delected in the miniiij; district, Joined with this evidence of the erop-
jiiiii; of the Fortymile series farther north, goes to show that the folil
is in the nature of a comparatively >,'entle dome from wliieh the strata
dip away on three sides at least — to the north, south, and east. It is
at the jirolialde siiiiiniit of this dome that one end of the line ineasur-
iiij: the width of the Ixdt occupied by the I'dreli Creek series is taken.
At the olheror southern end the marbles reported apparently iiidieato
the existence of the Forlymile formation, iiiuler whieli the IJirch
Creek formation passes. The total lenjrth of this line as thus meas-
ured is about :.'.■) miles, and thi.s width, with an average dip of lo",
gives a total thiekness to the roeks of the ISireli Creek .series of not
far from J."),im«i feet, which is the same result as that reached iude-
peiideiitly, with ((iiite dilTereut data, in the Fortymilo district.
.MICHOSCOl'IC STrilV OF HIKC'II CKEEK ROCKS.
The igneous rocks which arc intrusive into the altered sedimcn-
taries of the Birch Creek scries will be described later, and for the
present only the nature of the original sediments and the derived
schists will be considered.
As already slated, the nature of the rocks in the Uirch C'reek series
is oomparat i vely uniform throughout its whole thickness, and the rocks
are also identical in aiipearance at the dilTerent localities mentioned
above, which are hunilreds of miles apai't. Nearly all specimens
appear in thin section as slightly altered quartzites, composed of inter-
locking grains of (juartz of nearly uniform size. In many eases the
outlines of original detrital grains are plainly visible, being shown by
a faint ring of indeterminable dirty material, which must have coated
the surface of the original grains. In other cases the outlines of the
original grains are very faint and often can not be discerned. This
is probably due to the circumstance that the surface of the grains
was entirely clean before the additi(Ui of the second quartz. In all
ea.sestlu,' interstices between these original grains have been tilled by
crystalline quartz, which has grown onto the grains in crystallo-
graidiic continuity, as is usually the ease in ((uartzites; so that the
rock is now composed essentially of irregular interlocking grains.
KA.
Kri'iiii I
'I'llK KOUTVMILI-: HF.KIKS.
14.-)
Thf widtli
icli j;''"'!it''i"
ii'di Ci'ct'k
iiiai'lili' lias
width over
llio lUi'ch
to tlioso ill
its of iiiiir-
tlic iiortli-
ircli C'rt'ck.
lartzitcs, as
if tlu! crop-
lat tiie fold
1 tlio strata
(•ast. It is
III' iiioasiii--
.'s is taken.
Ily indicate
the llireh
thus iiieas-
dij) of W,
M'ies of not
u'lied iude-
[■ic't.
1 sodiinen-
iiid for the
lie derived
'reek series
1(1 the rocks
mentioned
siieciinens
led of liiter-
ly cases the
fj shown by
lave coated
lines of the
lied. This
the y:raiiis
rtz. In all
en filled by
I crystallo-
so that the
iiiff yraius.
lifsidi's t\\\nr\/. tiii'ic iiic rarer iiiinerals, wliiiii iir in rouiMlcd
firaiiis aii<l are |ilalnly ordfliital ■iriy:iii. Small frauineiiis of /.ircoii
are eiHiimoii; feidNpar is soiiirl iiiii's found, and (icci^ionaliv apaiit«\
epidule, and <'aicMte. liy iiicicasi' in tlie aniipiinl of ralcili' I lie
(liiartzites Ki'ii'liiiil'.v P"'"* i" "I"' >>l'l>"'i' l'"i'' "'' l'"' ^''lic- inlo the
iiiarlili's of the Koilyiiiile formation. In some <>( ili.- liiivli ( ici'k
scliists there is a larire amouni of carliomu'i'oiis luaiier, sonifi imcs
eoini)lelcly alteri'd into graphite, which is also cvidi'iiliy an orl;:iii.il
constituent.
Mctamorplii'c minerals arc usually nincli less in amount llian ilie
ori-inal deliital matciial. hut are present in nearly every si-clion.
The mosi iiinoii nictamorphic mineral is mnscovite, wliicli i urs
esiiccially on the slippin;; surfaces, or planesof >chislosity. I'.iol ilc is
often found, sometimes inclosing /ircon or sai;cnitc wclis; idiinnaliiie
is very common, and tcarncl is conspicuous in some of llic rocks;
irrecn liomhlcndc and a<'l iiiolilc arc occasionally met wilii. .\m>ilicr
class of secondary minerals which |)rohal)ly li;i\c a ^iiudill.v dilVcicnl
oriiiin, Iteiiiif due to aqueous rather than to dynamic action, ccuisists
of 1 asioual, sometimes aliumiant, crystals and ^n'aiiis i>( pyrilc, and
iron in other forms, such as specular iron, limoiiilc, and sideiile.
Marcasite is frc(|uciil in perfect crystals, and f'opper pyrilc, ofieii
yieldiiiii' a niccii slain Ironi dccomposil ion, is mil unusu;il: naleiia is
sometimes found in i;i-aiiis in the schist as well as in i|Uarl/, \ ciiis
which the schist incloses. All these secondary minerals, whetlier
the result of shearin;; or deiicndi-nt upon ai|iieous causes, nceiir in
evident relation to the slippinj,' planes in the i k, as can lie seen in
thin section, and .ill often form perfect crysijils or iriei:ulai' plates
which liave,u;rowii around and inclosed tlic oriLrinal delrilal grains.
THE KORTYMILE SERIES.
(iKNKK.M, IIKSCIMI'IIDN.
( )verlyiiii; the schistose ([liartzites of tlie IJircli (reek scries is ,i con-
siderable tliicknessof inler<-alalc(l nnirliles and (inarl/.iles, with hofii-
hlendic, micaceous, ^i'ainet iferous, and sometimes ni'jiphilie schists.
The marl lie lieds, however, arc f lund in all jiarts of the format ion and
form its chief (list inctixc I'c.itiire. To these rocks arc i;i\cn the name
" l''ortyniile series," since i iiey are exposed in ;rreal detail aloiiir l''orty-
niile Creek, and there alTord lieiter oppoi'i unit ies f<ir st udy I li.iii at
any other [ilace \ isite(l.
The Foi'tymilc series seems to pass f::radually into the Itircli (reek
series, for in the upiicr part of the latter the i|uai't/ites urow calcare-
ous and ]).iss into the handed marbles iind i|iiartzites which are found
at the bottom of the Fortymile rocks. Often these i ks h,i\c lieeii
so little altered that their oriy:iiial se(limeiitary nature is clearly dis-
ceriiibl(> in the field. This is well shown at the junction of .Moose
18 GEOL, PT '■'> 10
'^■™5H
lu;
(ii'.oi.ixiv or Till-: vikdn (iui.u idsTiucr, ai.aska.
( rcik uilli I'lPilyiiiilc (reck, where there oeeiir iiiterlH'ilded tniu'liles
aixl <|iiiirl/ites which ;ire <iiily hieiilly slieiired to iiiiy Uj-eat extent.
'Ilie^e .|iijirt/ites iiiiil iiiaililcs alleriiMie in l)i'cl.s, often 4(» t»f '(O (Vet
thiik. Imt liecincnliy tlie thicknessdiriiinisliesfo a few inches. From
the (|Uarlzile there is a firadiial Iransilinn lo more altered rocks, such
as mica- and hoiid)lende-sclMsls, ol'len ^iarnctifcrons. 'I'hese schists
arcol'tcM so nielaiiioi'phoseil tliat were it not lorllu' fact that tlie niar-
Ide remains llie same ami occnrs intcrstralilied witli tlw scliisis in .1
\ei'y intiiiiaii' way, Jnsl as it does wiili the (inart/.ites, it would he
dillicull to n HI"'''"' 'l'"'ii' "I'ir^'i'i"! sedimentary imtiirc.
The ^'ladnal transition from the (|nart/.ites and (iimrt/.ite-scliists
to the horid)lende-, mica-, and f;arnot-scliists sii,irK<'«t'^ "'i't the latter
are altered from seijimcnls coiUainin;; more liasic material than tlie
tinarl/.itcs, and so are ca|ialile cd' foriiuiif; a j^rcater variety (d' lu'w
i":.,erals nnilcr the stress of dynamic action. 'I'he hornhlende- and
mica-scliisls. a^'ain, pass into very hiack ;,'raphitic schists, otteii
pyi'ilileroMs, which appear to he altered arLrillites, and which arc still
intcilteildcd with marbles, 'i'he u;raphilic schists seem to occur nio.sl
alMindanlly in the n|)|)ei' ])arl of the series, as the pure (piartzile-. ''<>
in tlie lower pari, w Idle the hulk id' the rocks <'onsisls of hornhU'iKle-,
nnca-. and uarni'l -schists. The m.irhle is everywhere preseid, often
in thin layeis, hid increasing; in some beds to a thickness of several
liundred feet .
T)IKKS.
Iidrnsive ij^neous ro(dvs .are alnindant in the l'"oriymile series, and
are of dilfereiit a^'es. Some h;ne boon so altered by the .same jiroc-
esses which ha\e produced crystallization in tlic sedimeidary series
that their iuneous nat ure would often liarilly be recoH;ni/.ed without
tlie aid of the niicroscopi'. 'I'hese rocks appear to bclonfX mainly to
the irranitii- ;ind dioritic families. ( )thor dikes which have been only
sliiihlly sheared show much less nietamorphism than the inidosin;;
rocks, and leave no doubt as to their iifiieoiis and intriisi\e nature.
l'"inally. there are dikes which show no nietamorphism whatever, and
which must have entered t]i(> rocks subse(|uent; loall important.inovo-
nicnts anil st rains.
On l''ortyiiiile Creek these dikes are everywhere abundant in the
bamli'd marbles, (piartzites, and .schists, especially on the South Fork
of l-'ortymile Creek, between th(> junction with the North Fork and
with I'ranklin (iulch. Here thi'V often form immense masses, the
different varieties cut I iiiLr across one aiiotlier in a confii.sed manner;
and tlie sedimentary rocks are disturbed and metamor[)hosed so that
tlie general structure was not surely niaih.' out.
In comiiosition t hese dikes show a ^'reat variety, but they do not
admit of any strict classilicat ion, since they jjfrade into one another,
and the rock of any one dike is i-andy exactly like that of any other.
'J'here are vjiriations from the most basic to the most acid, and the
I
KA.
('(1 niiu'l)l('s
I'lll extent,
or r>{) IVot
les. Fl'dill
I'deks, such
lese scllislH
lit tlie iniii--
uliists ill .1
t would be
zile-scliistH
t the l.itler
al tliMii tho
ety 1)1" new
ileiide- and
lists, otteii
ich are still
ocelli' most
lart/.ilC' •'"
lU'iihleiidc-,
■sent, often
of sevei'al
series, and
same ]>roe-
iitary series
'.ed without
i mainly to
e lieell only
le inclosiii}.;
iive nature,
atever, and
rtanl.move-
laiit in the
South Fork
1 Fork and
masses, the
ed inaiiinM';
Dsed so that
they do not
me another,
f any other,
•ill, and the
SI'l'tlK.)
TIIK I'OKTVMll.K SKKIKS.
147
chief forms may lie enumeial<'d. conmieiicinu with the st liasii', as
liyroxenite, lioi'iililendite, diorite, diorite-porphyi \ , «iuail/.-iliorile.
syeidle, liornblende-frranite. iiorphyry, and aplite. The most liasic
varieties, pyroxenile and horiil)lendlte, contain considerahle ipianii-
tiesof pyrrholile and other nn-tallii' minerals, while the extremely
acid aplites ehaiif,"' j,'radnally into i)iire ipiart/ vidns. jiotli ac'id
and basic rocks often iir in j^reat masses, on the holders of which
are aliundaiit line strin^'ers into the sedinieiitary schist, showin;; I heir
intrusive nature. The dilfereiit dikes often cut one another, and it
is usually the case that when two dikes of ditlVreiit varieties inter-
sect, the phelioiiiena show the nioie acid dike to lie the younger. The
nioi-e basic varieties of the dike rocks are in some jilaccs schistose and
ill other |ilaccs massi\c, while the extremely aciil rock, such as I lie
aplite, shows no schistosily or other deformation. Some of the hijrhly
iiietaiiiorphosed ijjneous rocks, wliicli are evidently the oldest, con-
tain <iiuirl/, veins, but the yiiun^'cr rocks, even such as are often
markedly schistose, contain none.
(.UAinz VKixs.
'i'wo sets of (luartz veins are cicarl.v distinfiuishable in the I'm-iy-
mile formation. < >f these two the less abundant has an intimate con-
nection with the aplite (like, for it ^railcs into these rocks in struc-
ture and coiniMisition. and cjin often be traced into it in a siiifile
(Miti'rop, the aplite cljani;iiiif to a vein com|iosed of quart/, and fcld-
s]iar, and this, by disappearance of the feldspar, into one of quartz
alone. These veins cut across the schistosity in the fashion of dikes,
and have not been di.stnrbed by any movement in the rocks.
Veins of the other .set are very abundant, both in the Fortymile
seriesand in the iinderlyinij; I li rch Ci'cek series. 'I'hey o<'cur spariii,i,dy
intl Idest and most schistose dike rocks, and not at all in theyoun^'cr
rocks, such as aplite. .Moreover, they afford abundant evidence of
havin;; been subjected to j^reat crushint; and deformation to;;ether
with the inclosinii rock, and it has already been mentioned that
these disturbai s have not a<'te(l at all u|)on the yotin^'er dike i ks.
This set of abundant (iiiartz veins, therefore, is (piite distinct from
that which is connected with the dikes and has a considerably
j^realer ag(>. These xcins are usuallv iionpersisleni, so that both
ends of a j^iveii vein can usually be found in a lar^ic outcroii. This
iioiipersistence is probably partly ori;j;inal and partly due to faultiiifj;
siiV)se(iiieiit to dejMisition. In jjfeneral the veins are parallel with the
schistosity. althou^di sometimes they cut across it at varying anirles.
\Vhciic\cr the inclosinu; rock has been niiich distnrlicd and rendered
markedly schisto.se the elVecIs of the movement are shown in the
veins also by a stiH-tchiiiir of those which are parallel to the -.chis-
fosity, and in exireino cases by a veritable shretldin^f; while those
veins which cut across the schistosity are faulted anil draiigcd along
I
MS Gl-.Ml.OCiY Ol- Tin: YI'KDN' 'ii'I.D KI'^IKU'T, ALASKA.
I|„. plMiirs ..I' IM..VCMIC1I1. Tin i'lV<'<-l of this slii'iiriiiir is sen in all
inirrosrupi.' s.M-licms c.f the viMii-, h.Miiii- iiiitiiitVst.'d \>y mm. Tons
inl.Ts.-.-liii'r sflsof paralii'! Irad iir.'s, aii.l in ili" wavy cMinclinn of
the <niartz. aini oi'ifn Itv more or Irss coinpii'lf vnannlal ion. Wlirrc
lli.M'i' lias hccn foiilini: as well as sln^arinv' in tlic inclis the inc'lo>.iii^r
(;iiarl/ veins arc ol'lcn violcnily conlortcil. 'I'licsc veins, wliellicr
.eeiirrinii' in tiie I'orlyniiie .scries or llie liireli (reek se-ies. oflen
eonlain pyrite. sonieliiues i;alena, ami occasionally free irold. 'I'licy
arc prohaliiy anioim- tlii' I'liid' sources ol' llic s:ol>i in liie ^■||l<on
iji^lrici.
s'lIISTdSlTV.
Sonic ]iaris of ilic I'm ty.iilc Miies. as. for example, tlic intcrlieddcd
marbles ami (piart/ilcs on l'ori.\ ...ilc Creek, neai tlic nioiitli of .Moose
('reek, are not ;;i'catl\- sheared: from lliis Iliere ,ire all transitions up
to hiu'hl.v crystalline schists. As s\i;;-;rcslcd in ( siderinu- the IWrch
Ci'cek schists. It is jprolialih' llal the mo\emcnt producin.ir schislosity
look plai'c mainly aloiii;- the oriiiinal licddin;;- planes, for the inter-
liamicil niaiMcs anil ipiarl/ites pass into inlerltandcd marliles and
crxslalline schists without lire ik.-' or ilisi-ordance in I he at I it ndc of the
rocks. The clTcci'< of the sheirinjr are shown hy the dc\(dopmcnt of
llictamorpliic minerals of cvdcn'l' secondary iialnre. such as liorn-
lilendc. niii'a. ami .v-ar.iiM. 'i'hcipiart/ veins, wjiicli ha\i' lor med chic (ly
aloiiu: the planes of scluNlosily, aiay also lie reirarded as a result of
mciaiiiorpliiMii. Allhoii^li these <|ii;irt/. veins were prohaliiy formed
siil)se(|neiii lo ihe inliia! sheariny:oi' ' he ro.'k, and aloni: ciianiicls con-
formal <le with t he sciiislosity which we re opened up liy I lie ino\ emeiil ,
yet the \oins themselves are ^;('nerall.\' .-^i rained, faiiiicd, and e\cn
shredded, .\lorcovcr, microscopic study shows that man.v iindonlil-
edly metanioiphic minerals, such as irin'm'' ha\e \ery often liecn
sheari-'d. sometimes '. iol.-iil !> , so thai in tin r present eondilioii ihey
are lirokcii and elonuiileil. It therefore a| pears thai snii.seipieiil to
the initial sh, irinn which produce I ilie niciamorphic niincr;:ls and
^axe rise III ihe i(na.t/, veins ihe mo\cmeiiis in the rocks continued
idoii;^- the si.me |ilanes, prodiicini; ^kiealcr inelaiiiorpliisin and defac-
ing;, in part, the results of tin' earlier movenient. It has al ready lieeii
staied ih.ll some of the dike reeks arc prol'oiindly sheared and others
only sliuhtly, whil-' those which ,,re e\ idently \onii;a:esl lia\e I'-njer-
^■one no deformal ; whaie\er. ll is prolialile, llieii, (hat llienio\e-
mcnl which prodllci'd the present >elii'>losc slillelnie colitiniled in
operation a .eiy Iniii;- period of time, during wliiidi [leiiod maiiyollu-r
chan;j;es occurred in the rocks.
c,i|,|i|Mi AND lAIl.TINti,
As a rule the rocks of the loriymile scries arc not jrt'fnlly faulted.
l''riiin a jioiiit on l'ort\niilc Creekalioul k' or l.'i miles alio ve I'orly-
mile I'osi. as far as (»"|iiien ( I'ctdx a distance in a slrai;i;lit liiic,
3i
MCA.
Ht'cii in all
• IMIII. 'foils
ailK'lloll (if
)11. WIllT.'
ic iiH-l(isiii|;
IS, wild licr
("■icS, ufll'll
;(.l.l. 'Ilirv
ilic Niikoii
iiilt'i'lii'dilcil
til III' MlPMSC
iiisitidiis ii|i
It;- Ilic I'.ircli
,' scliistiisity
!• the ililcl-
ii,'irlili-s anil
il lujc' lit' till'
I'liipiiifiit lit'
K-ll as llcH'll-
niii'il rliit'lly
a ii'siili (if
iiltly I'ciiiiicil
laiiinls ciiii-
lllil\ Cllll'lll ,
I, ami cM'ii
ly iiiiiloiilil-
lll'tl-ll lllM'll
nliliiiii t lii'y
I)>C(|I|C||I III
iini'i::ls ami
ccilll illllc'il
mil ili'tar-
Insuiy Itccii
I ami Ml lii'i's
ia\i' i"ii|i-i-
l( lll(> IIHIM'-
>M< iiiiii'il in
many iillu'i-
lily I'aiiltfil.
liDVt' l-'iirly-
rai;;iit lint*,
THE koiiivmim; skhies.
149
ilisi'i'trarilinir tin- siniinsit ics nl' the ii\ it. nf J'l or :>o inllfs — tlicri' is a
iii-aiiy iiiiil'iinii strike ami ilip: this strike is imrt lieast, nearly par-
aili I with llie i^eiieial i-iiiirse iif llie ri\ei', while the ilip is iiiirthwesi
at an a\ eia^'e aiiirle <il' '■>" . Aliin;,' this part iit' the river, therel'Dii
the l'"iiilyiiiile serie^ lias a ir»'neial ilip aw.i\ t'rniii the axis ol' the
Kuriymile ant ieliiie, .Miove o'ltrien (reek, es| iallyniilhe Sinitli
Kiirk. the rocks have lii-eii j^reatly ilisi nrlieil liy ilikes of iniiiien.>.,
si/.e, so that there is no iiiiit'oriiiily, ami the ;;eiieral striietiire ean not
1m> elearly iiiaile out. 'The aeeonipaiiyin^ (itrnie (li;;-. 7) shows an oiit-
erop of inarhle with some intersi ralilieil sehisison I'lirtyiiiile (reek
lielow ( »'lirieii t'reek, the rocks as exposeil ha\inira iiiiironii ilip.
Minor I'oldiiifr. even criinipliiifi, is locally fomiil, especially in that
pari of the series which is most traverseil Uyilikcs. This minor folij.
*
in;; has iil'teii come alioiit inter than tli<> nioveiiieni proilncin^r the
planes of sehistosity, I'ol' these schistose planes lollow all llieciir\es
ill the I'olils. .\ specjnieli of colitorteil ipiart/.ile-liiol ile-;.'ai|lel-sehist,
eviiil'its some liamis essentially of jnire (|iiai'i/.i1e. while i.arkcr ones
« oniaiii also iiiiieli liiiitile ami ^rarnci w ith iimseov iie. Tue schist o^lty
appears to follow all the curves of the I'olils. ,'iml micro>copic si inly
shows that liioiite ami ;;ariiel, both iiieiamorphie iiiincrals, have Itceii
broken ami stretcheil by sheai'inu pre\ ions to I he folding;.
.\l various pointson l'"orlyiiiil(> (reck faults are often shown dia-
i^raiiimatically ill Ihcclitrs.bi' the aiiioiinl of imiN'eineiit coiilil not In;
I I
l.OO (iKol.iiCY or Till'. VI-KON (iOI.O DISTUK'T, ALASKA.
iiscoi'laiticil l)y surli ciirsorv uliscival iuii iis Ihc liiiiilccl time lioriiiittcd.
F'n:. s is fntin ski'tfln's dI' sm-li ImiiUs.
.mix IS.
'riicii' is no mii\i'i's,il jdiiiliiii; in lln' i Us oi' tlic r'niiyiiiilc sci'ics,
])iil ill ilic iiiosi iiiltTiMi |Miiiiiiiis tlicif is dIIcii I'oiiikI a very pruiiii
iii'iii sri of Ji till I plain's. «liii'li (Mils till' sell islosily and I III' loldinj,' ami
is pniliahly dill' In Im-al raiiscs. Al twn pniiits dii {•"iirlyiiiiii' (reck
when' llic'sc jniiits were cspci-ially well di'\ eloped their at lil llde was
talNi'ii. and was fnniid ici he in iiiie ease, strike N. !S."i^ NV., dip :in ' N.,
ami ill another strike. N. 7-"i K., 'lip 7'> S\V.
(■(iMIi PSilli IN of polilYMII.K Ii'OCKS.
.\s alieaily staled, the l''cirtyiiiile rucks eiiiisisl essoiltially n(
iiiarliles and i|iiarl/.iles, wliieli jiass into linriilileiide-. iiilea-, frariiel-,
and ^'lapliile-seliists. Ily the aid of tlie iiiii-roseope tlie o.xaet striiet-
-^MGiul-iTC SCmiST
GARBLE MARBLC AND INTCRBCODtO SCHIST
Kid. "^ I'auit-' in I'.r-tx mil'* s.-rit's.
lire (it' these ditTereiit \ arieties and tile line uradat inns into one anothi-r
which they exhiliil may l>e acciiralel.x' studied.
M'lil'li. The marhles are (il'ten (|iiile pure, heiliir ;iia(le up en' irely
of coarse, interlockiiiir plates ol' crystalline cah ile. These plates
often show liciidinu: and sometimes enishiny as the result of shearin;:,
lint scarcely aii> development of new iiietainorphic minerals. Tlie
tils' staL'e in the Iransilion ol' icaililes to (|iiait/iles is shown hy the
pr'scnec of more or less niiineroiis del rilal Lri'ains of iniart/. « hich are
inclosed intlieealcite plates; Ver_\ often Lriai IIS are ('III i I'ely inclos('(|
ill a siniile ealcite crystal, showiii;; that theealcite is re;;eiieraled or
reerysialli/ed from its (niirinal form. In oilier pails t he (piarl/. grains
increase in iiiiiiilier iiiit il the rock is cs.sent ially a ealcare'ois (piart/ite,
liein;.'' madi> up clii -Ily of (|iiart/. u:i'iiins cemeiiled liy ealcite; and in
.some sections there are alternaliiiy: /ones, some of which arc tine
(liiarl/it<'. heiiiL' coinposed of del rilal (piart/, .'grains, cemented liy see-
oinhiry (|iiarl/. while others coiiiaiii less nnmcrons oiiart/, irrains
iiiclos( d in caicile. thus ^howiiiLT a perfect I raiisil ion het ween the 1 wd
rocks.
(^iiiiii:il< . — The pure (piartzites show their Iriie nature (|iiite well
in the liidd, and under the micidscopc exldhii comparatixcly lili le
1
liiM'iiiitlcd.
iiilc scries,
CIV lifiillli
ililiii^ mill
iiili' Ci'ci'k
I ii imIc w.'is
ip :io N.,
cntially of
. ^ai'iii'i-,
^fict SlI'llCl-
hlMiai-]
THK FOKTVMILE SEUIl'.S.
l.)!
one aiiDilicr
lip ciiUrcly
licsc plali's
il' slicai'iii;;,
crals. Tlic
lowii liy llii'
/,. wliicli ail'
cly iiicliiscd
;cii('rali'il ur
uarl/. t;raiiis
IS i|iiarl/ilc,
'III': ami in
I'll arc tnif
[iloil \>y sci'-
lai'tz LTraliis
ecu t lie I wo
I' i|iiilt' wi'II
itivciv lililc
4
iiii'laiiKii'pliisiii. N'cry nflcii tin- i'i>iiiii1(mI fnriiis ul' ihc i>riv:inal ilclillal
gi'aiiis nt" quart/ may Ix' (lisi'ciiicil liy Ilic faint Mm- nt" (lii't> kaoliiiic
material which IiiiiiikIs tliciii. licsiilcs Ihc ((iiarlz strains there are
also oc<'asinnally othiM" detrital rra^riiicnts, anions which feldspar, /.ir-
coli, and apatite may he noted. Asa rule the i|iiait/ites arc t rav-
ersed liy many parallel microscopic cracks, which are plainly the
result of shearing, and in evident conned ion with ihesc shear /.ones
are inciaiiiorphic minerals in Naryiiiii amount, such as miiscuvitc,
toiirmaliiic, and garnet. Pyrilc is also frciincnt.
(,>iiiiH:j-iiiirii-Nfliisl. — These schistose ipiarl/ites chanirc very i,'iadil-
all\' into more iiietamoriihic i-ocks liy an increase in the amount of
]iii'*aiii<>rpliic miiKM'als. Amonj; these an important class is distiii-
jriiislied liy the jrrcal dcvclniimeiit of mica, which is chiellx liintite,
altlioiii,di somctiiiics inuscDvite prcihiminatcs. In thi'sc nicks sunu*
zones ordinarily retain the striictiirc of the piirei- i|iiartzite-scliist,
while in ollii'i's Mie si'coii<lary minerals are irreat ly de\ cldpcd. These
latter a|ipaicntly represent impure liand.-t in the oriiriiial sediment.
Hesides i|iiai'tz and hint it e, there is jjciicrally irrccn hornlilcndc. pyriie,
and niai,'iicl ite. .V \ cry characlcrisiic mineral is cpidoic. wliichnftcii
occurs aliiindantly in pi-rfcct cryslall(i}j:i'ai)liii' developinciil , furmiiii^
louir prisms. \aryiiiLr in color from pale yellow to nearly cu|iirlc«..^.
<,)ii(t rl\-)ii)riilili ikIi -srhisl. — The iiiiartz-liornhlenilc-schists arccssiMi-
tiallv like the ipiai'tz-mica-schists, cvccpi that the liiii'iililcn.le prcdoiii-
iiiatcs iiiamoiint over thcother mclainorphic minerals, in sumic I'urms
the ro<'k is essentially a (luartzitc, in which the shapes of ihe oriirinal
grains arc plainly disceriiililc In lliis mck lii;lit-i;reeii hoinliieiidc is
often present in consideralilc ipialit ily. in plates uf rat her l.ir^c si/e,
I'oii^'hly arranged in zones. With the hornlilende is irciieralix' associ-
ated fresh lirown liiotitc. Neither of ihcse minerals have deiiniio
crystallographic lioiindaries. hut they inclose detrital ipiartz grains in
sui'li a vvay as to [ji'onc llicir .sccmiilary origin. In other specimens
the ipiartz liecoiiips less ill amounl and the hiiinlilende greater, so
that the rock assumes !iiegasco[iically a dark-gray, often iicarh' lilack,
color, with a peculiar luster due to t hi- minute grains of liiii'iflijciide;
and ill SOI 'ases the hnrnlileiide makes up a large part of the rock,
the rest still c( I II si St lug mainly of i|narlz. Mint ite is, huwev er, always
present ill small amniiiit, and the metallic minerals, sinh as pyrite,
iiiagnet iic, s] iilar iron, micaceous liemalile. p,\ rrhotitc, and ilmc-
nite. arc usually pi'csciit, often ahiindaiitly ; they generally furm
iieail\ perfect crystals, lint, sometimes are in irregular grains.
I:'liiiliilif .siIunI. — The unartz-niicH-scliists and ipiarlz-ho' n'-'-ndc-
scliists soiiicl iincs coniaiii epidotc in such large (pianlily .s lo mcriti
special attention. This eiiidotc dcciirs in long, nearly perfect crys-
tals, w liich cut across I he di|l'erenl grains if t he (iriginal rock w illiout.
disi ui'liaiice. .ind thus show cleat 1\ a scciiiidai,\ origin. Like iho
biotite, lioriihlciide, and other mclamorphie minerals, the c|iidi)te i.s
\:<-2 cii.oi.ooY oi- Tin; vikon (iDi.n iiistrict, ai.aska.
,,:.|ii,;tiilv inosl ahmidaiil h\'«vj: rrv\n\n /..ii.'s \v1mt<- tlii' iillcraliim
lias iMMMi'mval.'.sl. Ill ilirs.T|)i(l(ilifscliis1s, asinollirrsrliislswliicli
hav.- Ihti, iii.-nli..ii.Ml. llwiv aiv riv.|ii,'nl porl icMis wliirli still ivtaiii
ih,. >iiui'iiin-n|-a s.Mli iitaiy i.M-k. Iirinjr posf'l mainly ol'.l.'tri-
tal .|uart/ ;:raiiis, uitli o.-casimial fcl.lspar, /iivoii. aiialilf, and oilier
iiiilirrais.
<;nn„lifir<i,iti.srliis/. Aiii.ilicivaiiali"ii in these crystalline s.'liisis
is iiiarke.l hy the iiwrease ..I' ilii' .uMriiel. "Iii.'li is nearly always |. res-
ent, sdiliai il forms a \ eiy eoiisiiici s jiarl oftlieroek. Tllese uar-
iiels vary in s\/.r Iroiii e\t leiiiel.x small. microseo|(i.- iliineiisioiis loan
iiieli or s<i in <liaiiieler In the lii-hiy nu'tamorphoseil schist, 'i'lie ;,'ar-
iietireroiis sehi-ls contain also alniii<lanl niieaand ^^.-iK-rally .•onsi.ier-
ahle hornlileiicle ,111.1 epiiloie. which have the same haliit as in the
other \aiielies; the iransition. ilieret'ore. iiiio llie rocks which art
(listlntrnishc.l liy the predominance of hiolile and hornhleiide a iii,'
the darkc-olorcd iiiineials is very ^'ladiial.
(Inniil-iinisnirit, -srliisl.^A comparatively rare lypeoC rock is com-
posed esseiit iallv ol' iiiiiscovile and uarnel, ihi' latter lieiiii;- in <niite
larueeiyslals; il i- hi;ihly iiielamorphosed ami shows mieroseopieally
no evidence ,<( lis ..rii^iiial iial nre, all hoiiuh li\ analogy with other
rocks it is jir.ilialily sedimeiilar\ in oriizin. This rock is round in
port ions of the series which lia\ e e\ idellt ly lieeli sllli.jecled to yreal
pressure.
(1 riliillitir srhisl. Ill -.ollle |ll.|ce-.. e-.|peciall\ ill till' Upper part of
the serie>. ale Ncliisl> which .lie d i>l i iil;ii islieil by the pri'Sence of
ainindant carlioiiai'coiis and liiapliilic iiialerial. This ;ji\cs I he rock
in the hand specimen a Inst ions, dark-u'iay color, and under I he micro-
scope >liillin^' part iides of yraphile are e\ ery w heri- seen. liesides I he
Lniiphite. whiidi is ^nlioidinate in amoiiiii to the oilier iiiini'ials. tin'
rock consists iiKoily nf (|iiait/. hiolile. ami mnscoxili". >o that it is
realU an impure caildiinn'coiis form of the c|ii.irt/.-iiiica-si|iis| .
( 'iliiiiil' -sriilsl. ,\ \ ;iricly of I he uraphii i<- schists found in the llircli
(rei'k district, a Ion;;- I he Irail leadiiiir from Circle ( it y to I he i;iilclies,
is iiiarked liy alnindaiit cyaiiiti. in shori. .-imii pri>nis. In other
respects the rock is essentially a iri'aphitic <piarl/-niiea-scliist, like
others ali'eady deserilied.
S'-lilsliisi ii/iii(iiis ri>il:s. — There are sometimes oliseiwed dike rocks
w liieh have lieeii so iiietaniorpliosed Ity shearing; that t heir t riie nature
can often not he eerlaiiil> told in I hi' liehl, although i;enerall> deier-
iiiinahle under the microseope. In these rocks the original minerals
are proci'Ncd. allhoiiLih a marked and in places a profound cala<'his-
tic st met lire ilefaces I heir arraiiyemeiil . .Viiioiil; these dikes varieties
of the granite, diorile. and syenite families are most ahiiiidant.
n|{|(;l.\Al, NAiriiK (ij- I'dlirV.Mll.i; ItlMKS.
Tho.se portions of llw I'orlyiiiile series which are least metainor-
phosed all' plainly sedimentary rocks, heinir iiiterhedded marhlesaml
piMim]
TlIK I'OHTV.MIl.i: SKIUKS.
153
(liiiirl/iti'S. In till' iiiiii'c altcr'cd rocks, \vlii<'li licccnii.' sclii>lo-M'. tlii'
inarlili's slill alliTiiiilc will) Hif sdiislos.' liamls. sli.iwin.ir thai rvcii
tliiM'ari' ol' scilimciitary orifriri. .MmfovtT. tin- inii'nixMi],.' >1mi\\s a
■Ziailiial tiaiisilioii I'l-oin tin- nearly pni-c iinarl/itcs Id ili>- IiIl'Ii <-rvNial-
linc M'hisls in wliicli the jrnnlnal clianiri- liy tin- ilrvflitpnu'nt of ni.'ta-
niorpliii' ininiTals may Ix' ohscivi'd. In llicsf 1 lansilions ili.- altfiiia-
tion of liands of pure (iiiait/.itc-si'liisi willi oIIht liands c.inaininir
darker mclanioipliii' niincrals. such as mica and iiornldcndc. suiTLTcsts
linil tlicsc daikcr liands nprcscnl impure parts of tin- iniirinal scili-
mi-nls wliicli coiiiaitu'il a laij,'c jiropoilion of basic dctiital malcrial.
Tl -cmnincc of (iinirt/.. feldspar, zircon, apalitc. pyriic and snnu"
liioiilc anion.irtlic jrrains of tlicoi-i,i.'inal sedimentary r<ieks lias .ilieady
liecn spoken of as indicalinir thai tin' rock from uliicli ilie scdimenis
were dcii\ei| was of irraiiil ic nature. We may tlieiefor ii>ider tliat.
tlic liands which are now chani;cd into mica- and hornlilendi'-sclii>l
contained oii^rinally n hdelriial niateiial deiived from the darker
minerals in the uranite, while ilie pure ipiar-t/.-scliisIs were maih- np
chielly of ^;ranili<- quarlz. 'riiere is also evidence, in various parts of
the scries, of conirhnneratt's which are in general consideralily niela-
morpliosed. In the nppei' parts of ihe scric-, the irraphilic schists
indicate a si ill iiiorc impure scdimcnl and prolialil> the pieseiice of
oruani<' lili'- I'hc scries, ihcn, orii;inall.\- consi-led nl aliei-nalin^
hands of limesloni'. sandstone, conudonierale. and shale. ,i ml il appears
]ii-olialilc that the lower part I'onsisled chietly of pure •..indstoiie
while ihc upper pari was more impiii'c and c.irlionaci >.
iHsiiiiiirriiiN UK i-iii;rv:Mii.r. skuiks.
On l''ortyinile ( ri'ck ilu' rocks of ihc I'oriymilc series ont<'rop
conlinnously from a point >'• or 7 miles aliox c the post up to a point
lieyond I'ranklin tiiilch, which empties intothe South l"oik. r>clwcen
l-'ranklin liiilch and Chicken (reck, and lieiween I'ranklin (iulch
and Napoleon ( icek. the I'orlyinile series is overlain liy i;recn slate
and impMii' calcareous mils licloiiL;inu- to a younu'ei- formation, which
will he dcciilieil as I he Kamparl series; and also liy coiii:lomi'rales,
•irils, and saiiilsiones.u ilh slial> and i'oal\ licds. wliicli will lie descri lied
as the .Mission (reck series and which appear Ioo\erlie um-onforin-
alily liolh the p'orlymile series and the yoimirer .i:recn slati' and irril
formation, .\ short distance alio\e the .juiiciion of {■■ortymilc (reek
wiih Ihc Yukon the nicks of the j-'orlymilc series arc inerlain liy
sainlslones and shales « hiili ar nsidcralil.N' altered in jilaccs hut
which are still disi iin'li.\- youniier. and are also rcfi'rrcd to ihe .Mission
{'reck scries.
On the \ ukon, •"> or H miles ahovo the uionih of Sixtyinile (reek, a
series of pure while nuirliles interliaiided with micaceous schists was
noted. These undonhtedly lielonu to the same formation as the lieds
which have been des rilieil on l''ortymile Ci k. McConnelP also
I .\iiii K.'p' '"■"' ^>'" "'■" >>iii'>''y. < ' iii.i'lii. I^Nt^^'J. iii'w .-HTii.-. Viil. IV. 1.. ItiU.
l.')4 flKOI.OGY OF TIIK Vl-K(>\ GDI.H DISTRICT, ALASKA.
iMiti's llijit sonic mill's iilxivc Fdil Hrliiiiirc ;i Imiid ol' liincstono and
(lark aiunllili's. li'aM rsccl Ity luiiiii'roiis (|Uiii-lz \cins and associated
Willi micaceous scliisls. cfitsscs ilic ii\cr. Tlicsc arc |iriiltaltl>- also lo
be assi;riicil III llic Korlyiiiilc scries.
In lilt" liircii (reck ilislrici no opiioilnnily was liaii lo sliidyllio
FiMlyinilc scries III any cMcnI. On llicirail liclwecn Circle Cily and
llie irnlches, liowcvcr. niarlilcs and lii;rtil>' mclaniorplioscd niica-sciiisis
arc found in llic di'liris, and iliis didn'is is c\ ideiilly derived I'roni Die
Idlls ininicdialely adjaceiil. Al one point also a micaceous schist,
carryiiiir much cyanilc and li('|i)ii;,'inj: to a frroup which occurs aliiiii-
daiilly in Ihc I'orlymilc sci'ics, was found in oulci'op: and alon^' Iho
Cra/y Mounlains, which lie lo Ihc west of ihis trail, marlde is rcporled
to occur in outcrop. The i|uai'lziles and i|uarlzilc-scliists of the Rirdi
Creek for'matioii, which form practically I he iinl.\' i ks outcropping;
in tlic ;,'ulchcs, ajipcar hy their strike and dip to form a domediko
uplift, from Ihc center of which the sli'.-ila di]( away in nearly all
direilions. thus pa.ssin^ under the I'"orlymilc series, as here noted.
On the south side of the ;rulches marlile is rc|iorled liy prospectors as
occurriii}.' near Ihc divide liclwecn the ^'ukon and the 'I'aiuina waters.
In the Lower Kainparts of the \'ukiin, almut l.'i miles ahoNc the
moulh of Ihc Tanana, arc onlcrops of calcareous i|Uarl/.ilc-schists.
'I'licsc rocks arc overlapped liy the uiicoiifornialily oxci'lyin;; con-
},'lomcralcs and trrils of the Terliary. >>lhal eoniinuoiis oliser\atioM
can mil he m.-idc. and ihc a|ipcMralice of Ihc nmuiilains su^rucsts that.
there has lieci nsiilcralile faulting' on a lai;e scale, liclow the
Tanana. however, the i|uarl/,iles and (|Uarlzile-schists of the IJircli
Ci'cck formation outcrop for many miles alonjr the Yukon, except
where ii\crlaiii liy Terliary or IMcisiocene iieds; showing' thai tin*
outcrops liisl alluded to ai'c p'rolialily lo he assigned to the l'"orty-
milc series.
.Moiii; the Telly Ki\er, which runs close to the avis of the ;;reat.
{Tcani iciinc, I)awson' has noled limestones and micaceous schists,
which prolialily tieluii;; to the same series as has here been de.serihed.
(»ii the Wliite Uiver, Pr. Hayes- states that on the southwestern side
of Ihc fireat hell of granite whi'di covers most of the district through
which Ihc lower White Uiver Hows there is. liclwecn the Uonjek and
Koidern rivers, an area composed .ilmosi eniirdy of while marblo
and talcosc schist. It is probalilc ihat these rocks arc to I irrelaled
with the I'lirtymilc scries, and it may lie noted thai they lie on the
iippiisiie side of the ^■ukon L,'eantielin(! from the rocks aloii^r P'orly-
inile Creek.
IIIICKNKSS (II' I'dJiTVMII.I': HdCKS.
No satisfactory cross-section of the l-'oriymilc .scries was oliiaiiicd,
so Ihc thickness can mil be y:iven: il is probable, however, thai it is
somcvvlial less Ih.in thai of the I'drcli Creek scries.
'Ami. U.'iil. 111',.!. Nut, Hist, Siirvry I'liim.lii. I-«7 '•«. new ....i-ii's, V..I III. I'lii't I, )i, .'KH.
»Nii( UfiiK, .MiiK . Miiy l.'i. iwr.'. |, ||ii
Tin; FORTVMILE SF.RIKS.
i:.5
KESIME.
I
1
'I'hc Fortyinilo . series cniisislcd ori'jfii'.ally "t" a ••i>nsi"leral>lc iliick-
ness i>t" liiiM'stuiics, saiidslont s, shales, ami (•(iiifildiniTalcs in a'.leiiial-
ilijr lii'<ls, tiie sei'ies Ix'iiif;' eaicareims at the linltoin ami lierdiniiii;
rather slialy at the t(ip. These roeks overlie the iiireh (reek <niarl/.-
iles, into whieli they exhibit a ^'radiial transition. Tuiii'l her with the
liireh Ci'eek roeks, they have l)eeii I'oltled, fanlte<l, ami sheareil. 'The
lirst alterations which prohalily aei-onipanied the I'olditi^r whieh ^raxi-
rise to the Fortyinile anticline were niovenieiits producin;,' schis-
losity, the intrusion of ilikcs, and tlie formation of ([uartz veins. It.
is probable tliat about the same time the pild which is found in con-
nection with the <[nart/. v<Mns was introduced. Siil(sc(|ucnt to this
foldin.ir the moNcments in the roeks continued, and certain i)orlions
iK'canic more schistose, so tliat the \cins already mentioned were
s]ieared,and metamoi'phic ndnerals forme<l in the initial disiurbanee
were broken and ilrawn out. Subse(|ucnlly numerous dikes cut their
way into the series. Some of these diki's e\hii)il slif,dil schistosity,
show in;; that mmcmi'nt in the rocks si ill continued. There arc, how -
cvei', a linal set of dikes which show no elVccIs of shearini: whatc\cr,
and which arc thei'efore subse(|m'nl to the last imporlanl mo\cmcnt^
in the rocks. ('omie<'ted with t hc,-.e last dikes and ^radini; into them
arc i|inirt/. veins which ililTor from the oriu'inal \eins in hein;;- unbro-
kt>n ami persistent. i''roni this il appears that tliemo\erncnt in the
rocks, in'odnein;; various defiu'niations, lasted I'm' a lout: period of
tiuH-, and that dnrini; all this period dike i-ocks were int rinlecl into
tho sei'ies at intervals.
I
THK RAIVIPART SERIES.
i'i;i:i.i\iJNAi;v st.\ti;mi;.\t.
.Vt a hinhcr hori/.on than the rock> of the p'ortymile series, ami
probaiily directly ovcrlyin.i; them is a scries of ^rcal ihi<'kness,
whose rocks arc characlc'ri/.cd ihroui;liout by nearly constant litho-
lo^rical 1 uliarit ics. These peculiarii ies j;ive a certain uuiformil \ of
appearance in the Held, and. when carefully studied, point to a simi-
larity of <u-i;j;in; and an these lilholoi;i<'al ^'I'ouiuls alone the rocks
have 1 n Lrrouped toirether ami l he name liamparl scries iriven 1 hem,
fiiun the fact that they are exposed in the Lower Uanipaits of the
N'ukon.
One of the most common eharaclcrisi ies of this scries is a ^'eneral
fjreeii color, which is possessed by ditVereiil roeks which may other-
wise show little resendilance to om- am)theV. The presence of vol-
canic material is likewise a distin^'uishiuK teature, and these litholo;:-
ical charai'terist ies arc idiMilical in t he ililVerent localil ies where tiiis
.series luis been exaniiiu'd, which are humlreds of miles apart, A
If
I.
11^
J
l.Of! (ir.ol.oOY OK TIIK VrKON (iOl.I) DI.STKICT, ALASKA.
(•(.iiiiiKiM r<"'k is (liiil);isc, (il'li'ii oliviiif-lx-iiriiii:, ami v;rryiii}: liiil lillh^
III cciiiiiiositinii ami ;iii|n'iii;iiii'i' in dilVcri'iil localil jcs. From llii' way
ill uhicli llii> (liahasf nccins il proliabiy rcpivsciils for I lie iiinsl part
sill lari' Mows, aillmiiu:li it also is I'lmiiil in tlikcs cntl in;: the associatcil
1 ks. With the ilialiasc an- found tnlTat'cous scilinicnts. wliicli an*
(Icrivfil fill iicly from the ilialiasc. ami iIh-sc loini a very larp" and
inipoitant |)arl of the scries. 'I'licy ;rrail<' into inipuri' linicsloncs,
often L'laii itie. and liard irreeii shales. The ,i;eiieral .ureeii color of
tlic foiiiiatioii is due partly to the ilc\ elopiiieiil of ulaiii'oniie in the
tiitVs and inipiirc s ■diiiieiits. Hiil cliiell,\- to the iireseiicc of .serpentine,
chlorite, and oilier i^recii minerals aiisin;;' from the decoiiiposil ion of
the i;riieoiis rocks which have coiilrilnitetl towanl the iiphiiildin^' id"
the I'litile series.
HlsimniTION AND (IKNKHAI. Kl'.SClUr'TIOX.
F'irh/iiilli Criik. Sntilli l-'iirk.—iU\ the rid;,'i' dividing: Chicken
(reek from the Soiitli l-"ork of l''ortyiiiile Creek, ami in a correspoiid-
iiii; position in the lied of the South {''ork itself, the niarliles. Iiorii-
lileiide-schists, and i|iiart/ite-scliisis of the j-'ortymilc formation are
oxcilaiii liy roeksof decidedly yoiin.irerappearance. 'riiescro<d\s \ary
in striicliire from massi\e to shaly. 'I'liey are well indurated, and
.somel iiiies sheared, lull only rarely have metamorpliic minerals liceii
dexclopcd In eollsei|llclice of the sheariiiir. so that true s(dlisls are
iincomiiioii. .Small quart/, \cins are occasionallx found. Init arc con-
siiicMoiisly few as compared with the veins in the l^'ortyinile series.
The rocks .III' microscopically (let criii ilia hie as dial lasie I iitVs, calcare-
ous ij;rils. often lilaiicoiiitic. ami coiiipael ureeii slates. This scdinicn-
lary series Is cut liy dikes of i;ianitc. often diorilie, and so eliaiiy;iiiy;
to i|iiart/-diorit" and al.so liy dikes of porphyry. .\s a wlnde, the
scries is cliarae ' l/.ed by a Lreiieral ^rreellish color, which the micro-
scope shows sometimes to lie < I lie to ula neon it e. 1 nit oft eller to chlorite,
serpentine, and other minerals dcri\<'il from the d mpositloii of
minerals in iirneoiis ro(d<s. On Napoleon Creek this series is iiueoii-
foriiiably overlain liy coii;i:lomerates, sandstones, and shales, which
carry CI laly la\ers and which ari' suliscipieiitly deserilied iiinler the
name of the .Mission Creek series. The lilack carlionaceoiis shalesof
this later series also appear to o\crlapthe i;reeii rocks in the lower
part of Chicken Creek, so that theoldi'r si-rics oc(Mi|>ies a conipara-
ti\cly narrow hand.
Ill Inn II luirliiuiih Criik iruil Missiuii Crnk. — .Mon;; the \'iikoii
for ahoiit -•"' miles hclow Fortyniile Creek are hiaek whales and tliin-
hedded sandslones, which are coiisiderahly faiil1(>(l and folded, and
wliieli are locally sliu'litli^ nicliiinorphoscd, hut never so iinndi so as
tiio oilier formations wliij-h have heen deseriheil. These hIaek shales
and sandstones appear to Ixdoii^' to a yonn;j;er fornialion, and have
been eorri'latod with Ihu eoiif^lDiiierates, saiidsloiios, and shales which
I
J-lTIIUl
TIIK KAMl'AKl' 8KWIK8.
i:.
o\i'i-lic niiciiiil(inii,ilil\ iIk- ;ri'<'fii nicks i>t' llic Uiitnpiirl rmiiijil inn cm
Niipdlciiii ( rt'ck !iiiil (liickcii I'fi'cki ami In llic^^i' rocks \tn> liccii
jrivcii llic iiiiiiic Missiiiii Cicck scries.
Al II piiiiii aliiiiit :.'•") miles IicIdw Koiiyiiiilc C'l k llic shales ami
lliiii-hcililccl sandsldiu's arc succeeded by massive dai'k-L'rceii rocks,
wliieli clwiii;:e in plai'cs to dark-u'iay or ilaiU-hliic color. Iml still
iclain their massi\e si rnetnrc and their peculiar lilliolo;:ical charae-
tcis. .\l lirsl these i ks alterualc in broad bamls with the black
shales uliii'h have alrea<l.\' been mentioned, and then they «;omc in
continuously until about '< or in niilesabo\e Missimi Creek, where
tlie\ are a;;ain siici led b.\ black shales ami thin-bedded, ;rra,\ ,
slialy limcstcMics, which probably bcloiif; to the scries exposed direct 1\
below Kortymile Creek. 'I'hc belt of massive dark-'rrccn or darU-blue
rocks exposed between t licse shale areas is cut by oce.isional dikes,
some of which are very litrhl yellow in color, and probidily corre-
spond to the aplite dikes on p'ortymilc Creek. The rock I omes
schistose in bands or /ones, ami in these portions contains (luarlz
Veins, althoiifih always in iiiiieh smaller amoiiiii than the ro(d<s of the
I'ortyiiiilc and I'.ireh Creek series, .'^ome of these veins are ot' (|narl/,
some of ealcite, and some of i|uart/, ami caleite crystallized toirether.
'J"lie.\ nearly always cut across the rock, and show no exidencc of
shcai'inj;, thus formini;' a stroni,' contrast "itli the xciiis of the iinder-
l\ in,^' series.
The iiat IMC of these massi\ c j,n'cen and dark-lilir rocks is not always
tipiiareiil in the liidd. but microscopic cxaminaticui shows that they
are in |)art coarse t nil's eontainin.i;' frecpiciit lar;;e frairineiitsof oli\ ine,
]ilai;ioclase, and aiinite in a confiised frri'tilidmass made up in part ol
serpent i lie, which irixcs I hciircen color to t he rock. These ; nil's, there-
fore, appear to be c|cii\ed from an olivinc-diabasc (U' a closely ndaled
rock. They jiass into liiie-ii'rained shaly riHd<s which are of the >aiiie
character but lia\ i' a .izrain so line llial 111 niiponenl minerals are
indisi iniruishable. The lit holoLrical characiers of these i-ocks, there-
fore, are exactly those of the similar rocks described in the neitilibor-
hooil of l''r;iiiklin (iiilch. on l''ortyniilc Creek, and the two formations
may be correlated.
Missiiiii Criik. — The main bramdi of Mission Creek iscallcd Amer-
ican (feck, and Hows into Mission Creek only a short distaiic<' abo\e
its mouth. On .American (feck, at a point about J miles above its
.junction with Mission Creek, the black shales and I hin-becldcd liiiic-
siones which outcrop at tlie imiiith of Missicui Creek are iimlerlain. in
apparent unconformity, by dark-irrecn and dark-;jiiiy massive roi ks,
which locall.v become slial,\ and which are evidently in the same belt
as till' similar rocks which have .just been described aloni;' llic \iikon
Mivcr above .Missiiui Creek. l'"roiii this |)oinl ahui^' the trail which
leads lothc^'old diirjfinij;s on .Viiicrican Creek the chief rocd< exposed
is dark j;ray or dark blue in color, locally u'reeiiish, ami apparent ly is
{
ii.
lri8 GKOI.OOV OK THK YUKON (iOI.D hlSTKICT, ALASKA.
l.„ ly MM iiiiprnv >lial.-, .'liMiiiiiriu' i"l-- slialy liincston.'s and lulTs.
In n.i's vnrk aiv .v.-nwliMv /..iirs .,r sh.aiin^', al-mir which tiic iiiuo-
slun.'.«.ha\vl.c.'iisili.-iri...l.i.i<«luciii-.silic.MMisliiiifst"iioaii(ljas|.croi.l.
Tli.Tc aiv also, l.pcally. Inir -luarlzKcs, whicli ali)ii« slicar / s
1 sli^'hll.v iiirlai •|.1mis,..| an.l aiv cliaiactrii/.cl l)y llir .l.-v.-l-
„|,„„.„i .,r i„ii>.M,vil.'. <»M ih.. up|MT pari of Ain.Ticaii Civck, at llic
,.|i.l<.nh.-liailshi.wiiniilh.Miia|Kl'i. \ I.VIl I. p. :!:!:). I h.- hmU is very
massive an.! .laij^-iiivfii in <;,\nv. Il is -nicrally nmrh joiiiK-il, and al
nn<- point \N licr.' llicM' Joinls uov ivniarkal)iy wi-ll developed the ehief
si'l «asnearlv JKiiizonlal : at the same place w.. re \vell-develoi)i'd sliear
/ones with a'striiceor N. :■< K. and a dip of :r> XW. Alon^ these
sheai' zones \eiMsof .(uartzand cah-ite jiaiiillel with the sliearinyr liav<'
been formed. 'I'hese Veins often contain e,>pper an<l iron i)yrite. In
tlie jrravelsarealiundani lijnetite and Itarite, often in iarjje p(d»l)h's,
indieatiiij,' the presence ol rarer minerals in soi f t hi' veins farther
up the ereck. .\s noted in other localities where the rocks of this
seiiesare found, the veins are hardly ever luokcri or sheared, hut cut
across the rock without displacement. .Microscojiic study shows tiuil
these roeksare lar;;vly of ntnloulttedly t ulVaceoiis ori}j;in, some of them
consi.stinjr chiclty of serpentine which contains frai;mcnls of residual
olivine, while others are made up of finely i iminutcd fiaj;nieiits of
(luartz uiih extiemdy abundant <'hlorite and other decomposition
products. These riic'ks are cut by •asional ilikes, amon^ whicli
aplile ami mica-lam|)rophyre ha\e been identilied.
Jlifiniii Missimi ('nil,- '111(1 Circli r////.—Sonu' :i(l or 4U miles above
C'iri'le City, on the Yukon, a .series of thin-bedded limestones, uray
ami often lithoitra|>hic, which clian;;e loeally into black shali-s, ami
which will be described later, is succee<|ed by massixc dark-blue and
dark-^rreen rock, weatheriui; red. and therclor iiispicinins from a
distain-c. This red eoloi- from weatherinir is characteristic of the
rocks of the liampart series, b(>lni; due to the oxidation of the abundant'
iron, which in the pi'oto\i<l ndition, in condiination witli olhi-r
elements, jiixes the i;reen color to the fresh I'ock. These massive
dark-colored rocks are continuous until <hi' bejiinniu}; of the Yukon
I'Mats, a short distance above Circle City, and their appearance and
litliolonical composition seem to warrant a correlation with the rocks
of the localities which have Just befii described. Theyha\e been
.sluilieil microscopically, and are fouml to consist in part of diaba.se,
whicli occurs in siu'h a way as to show it jirobably to have been
nn>stly surface Mows. These diabases ehan;.'e to waterlaid lull's,
whose materials are plainly derived from (he duibase; and these tii'Ts
become ;,'lauconitic and calcareous, sometimes conlainiiif; traces of
or^^anic remains, and so pass into impure and .sandy limestiuics. \h
in the rocks of this same series from other localities, the typical tulT
has il j^roundnia.ss consisting' larj;-ely of serpentine and other indistin-
guishable components, which incloses fre(|uent fnijfinents of olivine,
auu;ite, and feldspar.
Till-; KAMl'AKl SKKlKf*.
159
1
On Hinh Ciiil;. — On llii' Hail wliicli Icails to ilic ;,'i)l(| (liK;riii)r«
from Circle ( ilv, at tin- |(i(iiil where it ercis>es liireli ( HM-k at I lie
'l"\Vel\ ellllle ( aelie, lliere i> exposed ill olllern|( a 1 \ |iieal <lialia>eof
(lie Kaiiipart series. 'This was ilie only oiileiop noiieeil aloiiK liere,
the loek in ;;eiieial liein;; eoneealeil Itv gravels.
Furl Ihiiiiliii III Mi/iKiok rc(,/,-. — Melow Cirele Cily Ihe ^■llko|| tlnws
for .several limiilreil miles lliroiiuli a piMl'eeilv Hal re^rjon. i-overeil l>v
sills and ;;ra\<'ls wliieli are mostly of I'leisloeene a^e aii<l wliiili were
proliahiy formed as sediments in the lied of a irreat lake. In all this
rej^ion no onti'rops of solid roek were found. 'I'lie end of this le\el
(•ouiitry, wliieli ;ioes liy the name of the \ukon Flats, is at l'uv\ llaiii-
Jiii, where tile ri\ er narrow sand enters a ean\<>n-like eliannel throiiudi
a ranue of low mountains wliieli lie lietweeii this jioiiil and the .jiiiie-
tion of the ^'nkon with the 'ranaiia. This portion of the \ ukoii
valles IS called liy the name of the •' Lower Uamparts."
The lirst lock found on i cropping' at the end of t he I'lais Jiist alio\ c
Fort llanilin has the same peculiar lilliolo;;ical characti'is as the
rocks of the localities already descrilied. |''rom this point similar
rocks are exposeil coiiiiinioiisly aloii^ th<' \'nki'ii for iiearl\ loii miles,
as far as the lieiid in the river alio\e the .jnnction with liivss ( reek,
where this .series is overlain liy con;,doinerales, sandstones, ami ;,'rits,
wliiidi are made up lar;iely of pidililes and. smaller fra^inents derived
from the nnilerlyin^- ro(d<s. The younger formation coiilailis seams
of li^'iiitic coal and aliiiiKlant plant remains, which show its ai;e to lie
jirolialily F.iK'i'iie. lielweeii J''ort Hamlin and this locality I he oldi-r
rocks contain a j;reat deal <if diabase, \ aryin^' in text iire I rom \ cry line
loeoarsely crystalline, ami lieiiiirofleii very fresh in appearance. This
<iialiase channes ;;radii.illy into rnier-i;raim'd, ;,'reen rocks, which in
turn pass Into jira.v, siiiool h-textu red rocks, and these into I hin-liedded
or arjiillaeeons and slat.v rocks, often calcareous. .Mtlioii),di the dia-
base is a typical i;;iieoiis rock in appear.iiice ami si riicl me, the rocks
into which it |iasseswith iioaliriipt transition liavi' well-markeil sedi-
iiieiitary eharaeleristics. and altlioii^'li niany opportunities f<ii' observ-
inir the clian^re from i;rneoiis into sedimentary rock were alTonled no
exact, line of demarcation could ever be found.
.\ll obseivat ion.i ^o to show that the diabase forms many sheets of
variable thickness, which lie contormably with the walerlaiil rocks,
and the usual abseii >f contact iiheiiomena bet ween t liese shi'cts and
the ad.jacent sediments, as well as the nature of the sediments tlii'iii-
selves, jioints to tin ncliision that the sheets were surface (lows.
On careful study it is found that the rocks const it lit in;; the transition
between the typical iiiiieoiis rock anil llio typical sedinientaries are
really lull's of varying; texture, which are derived from the minerals
of the iliabase, the coarsest lieiii;r made up of lar;re framiielits, so 1 hat
it is with dilliciilty distiii-;:uislied from the unaltered i;;iieoiis rock in
the'tield, while from this coarse rock there are irradat ions depending'
upon the comnilniitioii of tlii' component materials down to very line-
c
4
i-
MO (JI'.ol.DdV or TIIK YIKON liOl.h iii-Ti;ici-, ai..\>ka.
^rn.iii.Ml lulls iiiKl ai-ill,i is n.rks. in vvhirli llir liMi:mriils jiiv so
SlMilllaslnlHMil.listill^MlisllMl.l.'. AI..III: I ll is pM H nil Iw li \ .T I ll.' IMCSl
• •uiiiiiion vnrk iM-si.lcs I riir .liiilms.' is ,1 iiiiissiv... iliirk-jrivcii. I liiliii-
jriiiiiK'cl iiiir. liavinv' a liap-likt' apiM'aranrf. vnIm.s.' Inif naliiiv is
(.I'lni IK.I (Irl.Tiiiinal.l.' rxccpt iiii-I.t tli<' iiiicinsc.p.'. In places I his
1 ni.-s liM.'f-rainrd aixl .'haimcs In a (larl<-y:nTii, smnnlli-mxtiiicd
slai.'. whi.'h is nllni .•al.-nr s in /mi.'s. In I lirsc wati'rlai.l mcks
irlaii.-niiii.- is alMiiKlaiii. aii«l nii aih'inlinn prnili s silirc.ms ami
IVriii^'iiiniis 1-nrks, aii<l i\<'ii li-nc .•lii-rls nr jasitcniids. ivij, ^'irm,
l.inNMi. and lilac'k in <'n|nr. .lasp.M'nids lia\ inj: less varic.l cnlnr arc
alsn fnlMini alnn^' slliar/nui's liy drpnsilinll nf silica li.v pcrcnialiiijr
waters, and s c dnsc-icM iiivd l•nl•l^s liavini; a similar appcarancw
ai'c \cr\' linc-irraincd siliceous scdimciils.
The itH'ks (if the Uamparl series iiilhis rejiimi cniilain rie((neiit,
liiniit;li lint alinmlaiil. veins nl' c|nari/, ami I'alcilc, whiidi arc usually
unlirnken and apparenlly nl' eninpaialively laic nri;:in. They are
iKHipersistcnl ami arc associated with joint jilaiics and shear /ones
which arc older than the veins, and liavc, indeed. Iiceii the cause of
their format ion. The e\ idei f earlier motion isshown li,\ slipping;
planes wiili sirialcd snrfaces and liy local sliirht si ri'lcliinir or slii'ar-
iiiLr: in places, also, i here are frci(nenl breccias cemented hy i|narl/,
ami calcile. These shear zones, hnwcxcr. lliou;:h frecpieiit. are only
loi'al. most of ilic lock hciiitr finite massive.
Occasional ilikes are found cnttinjr this series, ami anion;: these
aplile has lieen determined.
M iliitiiil; ( 'n I /.-. ThcTi'iI iary cnn;;lomcrales, irrils. and shales which
overlie the rocks of I lie Ka III pa it series al)o\c Hess ( rci'k seem to lie
onl.v a comparatively small palch. toron M\i k (reek, a short dis-
tance above its moni h. typical rocks of the I Jam pa it .scries a^rain cninc
in. These are cssciiiially I he same as found below l''ort Hamlin,
since they consist of dialiasc chan^in;: into sedimentary rocks, sonic
of which become very linc-;{rained ami slialy. < »iie v ariety is a irrccii,
apiianitic, sinootli-tcxtiircd slate, which becomes red on oxidation;
other slate.-, arc daik-j,'ray or black from I he presence of carbonaceoiis
matter. The rocks a if well Jointed, and in places llie Joints are .set
.so clo.>c to;;eilicr as In form shear /.ones, alonu' which there has often
been si liei Heat ion and t he deposit inn of metallic sulphiilcs; and alnnt;
crevices have been formed quart/ veins, a few of which arc very wide
ami persistent and appear to contain ;;olil in small amount.
/lihriiii MiiiiiKil,- ( '11 1 1: mill llii 'I'miiniii. — For b^ or Jii miles below
.Mynook Creek I here milcrop at intervals coarse urceii diabase and
the associated rotdisof the Kampart scries; and the hills a sliiu't ilis-
tance from the river show ihe dark-red color which the rocks of this
scries iissiime on o.xidation. IJclovv these rocks, and apparent lyovcr-
l.viiii; them with approximately I he same strike ami dip. ciuiie liiiie-
stoiies, H:ray, litlioL;rapliic, a'ld often rarbniiai'cniis. jissnciateil Villi
shales. 'I'hese shales cairv indistincl plant remains which sii^rLtesl
. I I
upriiH I
Tin; u AMTA ur skhiks.
H!l
I>i'\(iiiiiiii iij.'('. l''irifiii III' Jii inili-^ lii'luw ihi- |(liici' till' l:ii'iii imks
ol'tlio Kainpai't si'iirt apilii apiirai'. In-iiiu' pr'nlialily hi'ciii;;lii up In a
Can It, si lice III) rliaii;;)' in tlii' dip is appaii'iil. A I litis poiiil I Ih' sfiii's
\h ('III liy ;;rfal ilil^rs iiT );raiiili> aii<l i ice ii pics a Ix-it I '■ or Jn milt's \\ iilr
aliiii;,' I III' i'i\ CI', Ix'liiw .\liii'li ii is i(\ I'llaiii iiiici)iil'iiniialil\ liv 'I'lTiiary
saiiilsiiiiii's anil i'iiiiy:iipiiii'iali's I'limpusi'il lari^cly nl' maii'iial "li'iixi'il
I'lniii llic liaiii|iai't i-ni'ks. Iii'liiw ihis paii'li <>( 'I'l'i t iar.v inck^ I Ihti'
ail' I'Xpiisi'il, a I'l'W mill's al>o\ I' I III' iiiniiiliur I In- Tanaiia. miili'il\ in;;
4'ali'ari'iiiis i|nai't/ili's, '\liii'li piiilialil,\ lirlnnu: In Iln- l-'miyiiiili' si-iii's;
an<l lii'liiw ilii' Tanana lln- ISircli ('rerk si-r'lrs is t-vpnsi'd. as aln-aily
<|t'sci'il)i'il. lii'twi'i'ii I 111' 'I'anana and I In- sea t lie icicks nf lln' Ua in pa it
Mcrics ail' nut cxpnsi'd alidiu: tin- ^'ukl>rl.
MK<iAsi ol'ic rllAKACTKltlsTK s oC llll. ItniKs ill' JHK ItAMI \l;i
SKKII-'.s.
Till' lurks wliicli liavi' lioMi di-sri-ilii'd rniin widi'l.x' si-paiatrd locali-
tii-s, and wliii'li IniM- Iti'rii cDrri'lali'd as tin' Uanipart si-rii's. an- i-liar-
a<'lt'fi/<'il ilii'Mii^iliuMi liy a uriii'ial ilark-tri'<'<'n rninr. whii-li rlian;,'<'s in
dark ii-d mi i-xpnsi-d siii'l'ai'i's. liy a | nliar iiias-ixi' si iiiri mi' and
liini li'xl nil', and by llif I'lnisianily ii'i'iiriiny^ i'\ idi'ini' nf Milraiiii'
airi'iii'ii's. 'riiinn;,diniit tlicsi' nirks ari' niassrs ul' dialiasi-, wliirli
appari'iiiiy IniM' llii' I'liarai'li'isnl' Noli-ariir lln«s: tlu-ri' ari' alsn irrral
tlii(d;ni'ssi's nf lull's di'ii\i'd I'inin tlit'si- dialiasi-s. 'rransiliniis I'i'iiiii
till- snlid dialiasc In tlii> t'liaisi- I'la^ini'iilal ini-k. inadr up nf dialtasii*
lid I'll lis, liavi' often Ix-cn nlisci'vcd, and rari'l.\ is ilii'ii- any cniitart
|)lii'iiniiii-iia nr any lini' nf si'paiatinii liriwi'i-ii I In' dialiasi's and llii'
lull's. Till' rnaisi' t nil's pass u:iadnaii\ inin lull's nf liniT iriain, and
llii'si' in tiiiii inln linc-ti'M nii'd ^lay slali's, wliirli lii'cniiii' calfairniis,
and sn pass into iiiipnii' liiiii'stniii's m- lii'i'nnii' I'ailiniiarrniis. <ilan-
cnnilc is \ I'i'y alinndani in llii'sc si'diini'iilary I'nrks. and ;,d\i's ii>i' liy
its altcralinii tn .jaspi-rnids nf lirilliant rninrs— jrrccn, Innwn. n'd, and
,'j;iay. .laspi-i'nids alsn arisi- fnnii I In' di'pnsitinii nf xi'iinyi'iiniis silira
in till' iiiipnri' liiiK'stniics liy wati'i' prrcnlal in;:' ainn.;; slii'.ii' /nni's.
Snini' nf llic liniT-;:iaini'd fi'lilspal liii' i ks aii' alsn indiirali'd in llii-
saiiii' niaiinci'. (HIht inrks wliirli alsn liavi' ni'aily llif sann' appi'jir-
aiiri' arr i-liiclly liijlil-^riay in I'lilnr and appear In lie \ ery liiii'-iiiained
silieeniis sedi liielit s nr liii\ aellliles. These lilie-irrained silieenns rneks
ai'e till' lianlest rneks ill the fnrniat inn, and sn are innst pei'sisieiit in
detrilal rneks wliieli are derivi'd Irniii the disinleLrral inn nf the rneks
nf the lianiparl series; therefnre pelililes in the yniiiiLier n\ irlyiiif;
cnli^flniiierates arc nl'tcii alninsl cxcliisix cly nf \ arienlnicd Jaspcrnids,
(.•lierls, and nllier silieenns rneks.
i ,
( l.AsSiril AlliiN 111'- rill'', HiiCKS OK Till-: liAMIWRr SKUIKS,
IHiilxifii . — The diabase iseveryw I ere reiiiaikably iiiiifnrin in appcar-
aiiec and eninpnsilinii. It is ;;i'iici'ally dark-jtrceii in enlnr, with a
IS iiK()[„ I'T ;! 11
_^
ICj (,1'iinrjN (iK THK MK"N (ii'lD hHTKIC I, Al. \SKA.
I.-Mii.v viiiMiii; It. .1,1 III!.- or M.-.iilvii|ili.!inii'' I'- r.-itln-f .-...iim- .ind
pflMllllliU . all'l -■"Mill llIK
lii;> ;i IttliU'll'y liiWillil Jl iiiiipliynlir stnic-
liiri'. 'I'lii- !fliN|iiirs iii 1lif
C. lill'^l- I'll
k ni-f li^'lit-^rnv ill folur, while
tin- ii'si 111" till- niJiH'i-tils ail' "1 .1 i.'1'iH-iii
I .Ijiik L'lf.'ii.
>licri>?«M>|ii<iiliy liii'sinii'iiiri' i> liM|.MT.\>iiiliii
ii-iiii<l i>rt*Mi opiiitic, llio
iiiiii' r.iis hi'iiii: wi'il <
t'liil-i :i!r iil.iviMi-liiM'
iv-tiilli/i'il Mii'l iiii<Tli>rkiii!;. 'i'luM'ssi'iilial iiiiii-
II 'I auiriti'. » iili cricii 111 licit (ii-tluK'lasf ami ili.ii-
ia^'i'
^.•.•.•>.^(.ij.'s wliii-li iilii'ii lirctpiiic M'l-.v iiiipoiiaiil. af<> oliviiM'.
ill', iiiii'.'iii-tili'. iliiiciiili'. 'iiiil
lim iilili'inli'. ^i'i|Miiliiii'. t'lM'liiii . i''iii-i
pyrili'. (»r tli.'M'ilii' nlivinc ix ahvays a |friiiiary niiiHTai, ami ilii>
iiiairiii'lil'- ami il iiili' pntlialily iifarly nl vvay> ; i|iiarlz is suiiii-l iiiios
priiiian ami w)iiicliiii.''«i\ iilciilly > mlaiy, wliilc I lii' ijilrili', "piil.ilr,
Miial
nilili'inli- !> iii'ail\ a'lwaxs ili'iivi'il I'niiii
iii| p\ rill' M I'lii 111 ili'piiMl iipiiiitlii' lii'iiiiiipiisiliiiii til tlii'i'ssi
a
('■iiisi itiii'iit iiiiiii'ials; till' II''
till' aii::ili', iiiiil till' vi'i'pi'iiliiH' ilMiall> rnmi llir ulis im', fn'i|iniil ly
(''Mill till' aiiiii'i'.
f,;/((M7:-«/'ii/"i.v' . -I Jiiail/.-ilialia'^i' I'in'i'is liniii llir l>|iiral mrk just,
(Icscrilti'il only in till- im-ii'aM- i>l' priinarx i|iiaii/ tn Mirli a i|iiaiitily
jis 111 fiiiiii .111 I'ssi'iilial I'lin-^titiiiiit 'i'lii> jrivi's tin- fork in ilif liainl
Npi i-iini'ii a Ji^ihtiT iiiiii )i;rayisli i'hIoi
Oh
iliiihiisi . Tliis vaiii't\' is M'i'v ci.iimioii ami is \\v san
a- till' iypical ilialiasi', cxrcpl that IIh' oliviiH- 'ii-^'oiih's an i">m'M-
lial lliliiiTal. 'I'liiTi' is soiiH'liiiii's i li'iiililii'\ !ii\v,ilil a poroliN lit ir
sitii.-inri'.
',>f(r(/7r-i(//c/)/( -i//'.Wi'i.s' . - in till' >iii;rli' 1 liiii M'i'tioii I'xaiiiilii'il Imtli
ijiiail/ ami oli\ ini' witi' mi ainiiitlam as lo In- l■^s"lll la! niiiii'ials. w llill•
tin• siriicl iiro o!' the loi-k \\asiilln'i'«isi' llu'saiiie as that ol' llironlinaiy
lypi'.
(Iiihhriiiil olirliii -iliiihiisi . -In a sinjli- s(H'riini'n pii-knl up in lli(>
"lloal" on IliiiiliT Cri'i'k, \Nliirli i> mii' of tin' liranrlii's of Mynook
( ii'i'k, till cssi'iitial ronsiitiifiils an' aii;rilf. iliaila^'r. ami oliviiu'.
ria^ioi'lasc is pi-i-si'iit in Muall anionnis, ami Ihi'i-i' is a ilcciili'il pii-ci-
lilir sli'iirt III Till' oil villi' is ureal ly alti'inl to MTjit-nliiit' in 111 irons
anil splii'riili'.ii' inassi's. 'Tln'ii' is a ii'iiiaikaliiy l.ii'i.'i' proport ion of
iiH'tallii' siiipliiili's in till' rork, anions whirli aio laaii'.isiii', pyilli',
cliali'opN rill', .'iinl pxrilioliti'. 'I'lirsi' siilplijili's, .jiiil;.'inu: i'loin tln-ir
lialiit. ail' pi'olialilN' imliLi;<'noiis aiul primary. Tin pyrrliotiti' roii-
laiiis a Ira I' ni>'ki 1, as drii' niiiii'il hy |)r. Siokcs. ol' Ilic Survey.
S' i-jii iitiiii -tiiiY.i. Iiiili'i- iliis lii'ailini: are elasseu eertai.i rocks
wliicli were c'lllccteil on 1 1ll' ^ nkon Uivcr almx c .Mission ;'rcek ami on
Aiiicricaii (reek In the hainl spci-imcn they arc darl' -urceii, heaxy
ami iiiassi\-c, « iili t he color ami e- tea sy feel of M'rpeiii inc. rmierllie
lliicr iscopc llicy are seen to he liiaile up eliiel!'. .if selpenl ilie « llicll
has no .-special .In let inc. In one of t he '>ei'iioits, liowcser, are Inokcn
ami irrctrnlar trrains anil siiidls of ojix ine, »\hieli pass i'.io serpeni ine
liy a process ol all era I ion; there are sinallcr frairiiieiits of plaLrioeiasc
l'el(ls|iai'. ricsjijes t he -.erpeiit iiie in t he lirouiiilmass t hen ■!••• ehloiite
w^.
Till. KAMI'SKT MLKIES.
ICS
II! I' I iPllicI' '|i'Cii|ii|(iisi| imi |ilMi|iii-U. ,1111 1 oil I'll ;i I III III hi II I IiKILMii-l III' .11 II I
tit III' I' ii'iiii ■>.\iili'>. \N Inch a I SI I :i|i|M'ai' In lii' i| iii|mi>ii mn iirinliii'is ;iiii|
to lie iliTisi'd I'll nil till' >aiiii' MiiiiOi' iis llii' M'i'|n'iil iiii'.
Itinliii.sif liiljs. — 'I'lii'M' riii'ks jirt' .sihih'I iim-'i I'uarsi' ;,'iaiiii'i| ami I'uii-
tain anirular I'lau'iiii'iils nf i;,'inMiiis iin'k>. wliii'li ari'MTv imi ii'i'aMi- in
llii' liaml h|ii'ciini'ii ; nlln-is an' liiii'-^iraini'il ur aplianilir. Tlii' I'lilm-
is ilark-i:rc'<'ii to m-arly Mack. T'.i ■ lypicai mar^i' lull's ari' niaili' ii|i
(if la;';;<' fravriiiciils nl' aiitrili-, iilis Im'. ami I'l'lilspar, all imiri' m lix>
(I<>coiii)his<mI. anil ari'ani;>'il wiilmiit iii'ilii: iln' Lrrniiiiilnia^.- is ll;ii'-
yiaiiic'l, anil cunsisls lar;:«'ly of si-i |iiiii ini'. In aiiipilii'i- iNpi' iln*
(.'roiimliiiass is iii'i'iluniiiianl ; il is a liin' iiiiiiniTV |iliiir\ sialliiii' iLri-'i''-
};ati', lary:i'l\ k.'iiilinicami si'i|iciilinniis. In ihis triinimliiia^sari' many
anun'ar nr siilian^rular I'lairnn'iils, suiih' uI' w liiili an' si'\ rial inclii's in
Icii'^l li, ainl all' liitlil -rnlmril ami punnis in I lie liami spi'i'lmm. I in I it
llic niicriisriipc siiiiH' lit" these l'ia;;iiiinls sfcni tn In- jjlassy, w liilr nl Iiits
vary fniin iiiirrul'i'lsiiii' tn fmrly cnsialliiK'; in tin- I.iIIit i-m-i'IIh'v
air apparcnllx iiiaih' up lartji'ly nf I'l-hlspar ami i-aliiii'. riii--i' Irai:
ini'iils si'i'iii III ii'pii'si'iii I hi' irn 111 ml mass III' snmi' \ iilranir imk amh'-
,sitr, iir liasall .
'I'lii' liniT-ijraiiii'il liialiasir lull's lia\i' I'sM'nIiallv i In- -aim' iriuuml-
ina'^'- as alrcailv imliil. « liifli I'unlaiiis lai'L."'. Iimki-n i'i_\ slals ul' aiiirili',
liiii'iilili'inli-, i|nart/.. I'l'lilspar. ami aiM inulitr. In mii' l>ii'alii,\ almvc
Ciirii'Citv- tliisdark-i^'ri'i'ii I iilV is spntlcil with many small, w liilc lii.iIiis
111" cah'ilf, wliirli nmliTtlii- inii'insi'iipi' slmw a tilirmis si riid iih' sinr
p'stiiiy: iii';raiiii' miKin. In .-.niiii' n'' ihi-si' nicks, .ilsu, ;r|,'ii||.|,niii' li.is
fiiinii'il aliiimlaiil l\ . The i|i iiipnsil inn nf this mineral In silica. I, \ pl-
cillv clialccilniiic, nfiiii splicnilil ic. ami In |iyrilc nr siilcrilc. may
often I Iisii\ I'll.
Iiiili li , iiiiniilili liitl's. Those i'licks which are cleai'l.N' nf I llTaeciillS
ori;.'in lull in «hicli the internal e\ii|enee is imi cniicliisix e as tn their
ilcri\alinii from ilialiase are ela.s.seil simply as inlTs. They shnw ,i
;;railiial traiisitimi frniii the tnlTs which an' maije up i>( ili.ili.i^M.
iletritiis, ami ililYer fnnii tlieiii ehiclly in llnir limr ;;raiii. In all
these nicks are small ileliit.il fiairiiicnls. cni; stiiii; miistl\ of i|iiarl/
ami I'l'lilspai. cmlieilileil in a Unc-'^railieil, inicroeiyslallim'. clilnriiie
ami serpent iiioiis ^I'oiiinlinass.
( liiii-shili .- 'I'lic llne-L:raiiiei| tiiO's pass ).'ra'liiall>' inin ilie c|;iy-
hIiiIcs liy ih" 'iisappcarani f the lar^'er ildriial fra;:iiicnis riicse
rocks \ai\' fi'oni liy;hl ;;rei'ii to nearly black in color, ami are smnnih-
tcMiircil. snineiinies cum par.ii i M'ly massi\ c, nlicner li>s||i' m- sl.iiy.
rmler the micnisenpe tlii'V ale seen In lie liiaile lip nf I Very line
a;ri:rc;;ale kI tin\ ilctrital i|iiarl/ ;,'raiiis. with much kaolinic ami
liiusciiN it ic, often calcarcniis ami carlhiii.iceniis, niatcrl.il.
('iirliiiiniii mis .sliili . Til » t.\ peilill'ils flnni the last i Ic-cril leil cji ielly
ill the presence of aliiimlaiil cai'linii;i Us material, which Ki\e> a
ilark-;rrccn nr iiearl.N' lilack color. The rock is )ri'iicrall> striiii;;ly
li.imlcil or sl.ii \ . ,iiii| p\ rile is lieiieiallv |iri'seiii in Jariic ci \ .-i.tN.
KJl (i|.lll,n(,^ .i| IHK VI KoN iH'li IH>TKlrT, ALASKA.
I,,i.l>u,. .siiiiilsli.in . -On 111.' >.iiiili I'oilx Ml K..n\ iiillr CiTck mihI mi
MMi.M.k ( ri'fk w.Tf iii>i.''l l»'<l-(.r ini|iiii. •.iiii.Niiiii>- ill ilif Uaiiiimrf
«.<'iii«. ■rhr.lrirltiil rriiym<'nl!.jir.' l.iip' ■><"'■ >'»->b cl.-ii-riiiiiiiil)l<', and
tliiTc i^ iMPiiM.l.ial.li- i-alcilc. iiMiiill,\ |>r<>>«ciil a** a ituhmiI. Tilt' nicks
ari' jri'a.X' 111' iri-i'i'ii in cnlnr ami ;;iaiiiilai- in i<'\iiiir. ThcN aii' inailo
up n( ••liPM'ly «'oiii|iarli'il iriaiiiN ol" .|Mai-I/, plairiiii'lasr. ami orl IiucImhc.
with ..llicr l.'ss-rn'.|ii«'nl ii.im'ial'>. Miii'li'il llii' ri'i(ls|iai' appears to
lie Miii'iiM'lliir. •<iii:;.'i'-iini,' a friaiiilii- ipiiirin. 'I'lii' mck riom l''(»rty-
iiiilc t ii'ck i-oiiiaiiis aliiimlaiii irlaiii'iuiiii' in iiicirnlar irrains. with
\\lii''li arc a»iiiiali'il a■^ a ili riiiii|Misiliiiii piuiliicl iiiiiiici'diis crystals
III' >iilcriic. Tlic inli'isiiic- liciwccn I he ildrilal ;,'i'aiiis arc usually
lillcil with I'alcitc. ami in ilii>calciic is ;;cm'rally cniisidcralilc plainly
\cniii;cm)iis pyrilc in pcrtVci civslals. On Myiionk < reck. Iicsiilcs
llic iron pyrilc is cniisiilcraliic clialcnpx rile, wliicli slains llie rock
irrecn on (iviilal loll. This Lrrein stain uas roiiml liy hr. I lillcliraiKJ,
ol the ^iirxcy, to lie a niixliircor caleile ami copper silicate. Two
assa\s of rock cari'yiiiLr this copper pyrilc ucre niailc; one, liy I'rol'.
( . !•'.. Miinroc. ol' \\ashin;.'lon, ;ra\e no i.'olil oi' silxer: ami another,
lp> l>. II. oiliccr. ol' Salt l.ake('ii>. i:a\c no irolil ami t wo-tom hs of
an oil n f sil\ er |o i hr imi ; a ilill'crcnl sample tra\ e Mr. ( Ulicer one
oiie-hiimlreilili of an ounce of l'oM .iiiiI no siher.
I IK I III 11 1 1 nil slum . Inipnre liincsioiic is loll ml a I iiiici \ als I liroiiyli-
oiil I he foi nial ion. Inn mil in LTieat ainoiinl These limestones are
yeiier.illy dark-^ray or dark-liliic in coloi-, and are made up mosi ly of
small ^rrainsol' crystal line calcitc. This ca lei te incloses del lit a I ^;rains
of ijiiarl/, leldspar. and imleierininalilc dccoinposition products: it
also soineliiiies contains earlHiiiaceoiis malerial and ;;laucoiiite, with
secoi;dai\\ silica of I he clialccdoiiic or eryplocryslallilic \aiicly, and
St Iar.\ lira in-. o||i\ rile and hciiiaiiti', so times pari ly altered to
siilclile.
/• nil -iiriiiiii il iinii rl-.ili , iir iiiirni'iihti . — This rock i-- I oil lid at \ arioii*
poinis in the {{aiiipart series, in npaiat i\ el,\ thin licds .Mci.'a-
scopicallx ll is liulil-y:recn and aplianilic. ami jiciicrally thin -ocdiled ;
iiilcroscopicall.N it is seen In lie iiiailc up of vci'y siirdi, roiindi'd ilelri-
lal grains of i|iiart/. eenicnled li> -econdary silica. There are also
occasionally piocnt iiiusco\ itc. /inon. and kaolinic and I'criiiyinoua
malerial.
.///.s/" /o/i/. The Jaspcroids .ire rocks .(iiisisliiiy: chiclly of silica,
p'nerally chalcetlonic or cr\ pio<'ryslalliiie. and ate plainly ilerixfij
from (he silieilicatioii of other rocks. They arc loriiicil in \aiioiiM
wa.\s. lull inalllriic .jaspcroiils the silica is secondary, ami inlidduceij
sllltseiplelil to the dcpositi'ill of the rock.
.\ii iiitercsliii;:aiid iinporlaiit variety is the iilaiieoiiit ic jaspemitl or
taconile. such as h.is Ihch ilesciilicd li\ I lic' w liter as oi viirrin^' aluin-
ilanll,\ in the iron-licariim i .cks of the Mcsalii I'lnyc in Miniicstpla. In
lilt' rocks of the Uaiiiparl series ii also appears that the ylaiieoiiilic
Till. KAMI'MM SKUIK.S.
ii;:.
liliifNliiiii'^ |i;i'»> mill ,iM>|iiTiiii|--, « liiill ,ili' I'lilnli'il nil. :;iciii. liiimn
(ir ;;i;i_\ li,\ iimi in il> (lillVii'liI riil'iii>. ur iHT.isiniiallv li\ iii.ilii:;iiii"«i-.
Of wliirli iiri' lii;lil-ui'i' V nr iiciiily while. ,i> a t("<iill nl' the ■•I'luiial imi
of IIh' iliiri. Tile |ilurc>scs nl' liii> (•liaii;;i' aii' i'\arlly lliiix- vvlinli
Iia\<' liiTii (loi'iilinl fill- III!' lai'iiiiiicN 111' Miiiii)->.oia.
A I'oi-k i'\liiliil iiiu ^^<'ll I'll' liaiisiiiiiri lii'U\i>i'ii llic irlaiii'iiiiit ii' lliin'
>|iili<' ami I Id- .ja>|M-i-oii| waM'nIli'i'li-il mi llic \ iikuii UIm r in i In' I.uvm'i
|{iiiii|iai'l>. linn- in a I'lilV \va'«'<i'i'n a lliiii ^cain nf In iylil-inl la*
jM'r. Willi ilaikiTii'cn lini-L.'iaini'i| imU nil Imili Nii|i'». v\liic|i «a- in
iinnn'"liali- ciiiilacl \\ it li I'liaix'l-lcxliiii'ij ^rii'iii im-k »lni«ii li\ ninTn
si'iipii' I'saniinal inn in lie tvpiral liilV \ lliin MTlinii nl' llic i k al
llic i-iinlai'l 111' I 111- hiivrlit I'l'ii .ia-|ii'|- "-eain willi tin' ijai k i,'iiin ilinl
i> inaili' ii|i inii--ll.\ nl' iT\ |ilnfi\ >lalliiii' ■•iiira. wliirli is rlialciMlnnii' in
|ilaiT.s. w il li splii'iiilil ii- aL.'i,'i-i'Lial('s >liii\vin;.'ilaik imicm-x iinili'i' rinssnl
liiciils. (ilaili-niiili- i> ahninlaiil in iiii'irnlar «rain> nf all -i/f.. ainl
till- ili'riiiii|Hi>it inn 111' 111 is III i una I. rnnniiii.' clialrrilnMii- siiii-a ami iinii
oxiijf. is M'cii in all its sla;.'is, jlic |irniess is thai nlisiMV cil li\ ijn'
wiiii'riii tin- iiii'ks of llir .Mcsalii ir m iaii:,'r. Tliis i|i-i'iiin|>iisiiiiin
aciininis Im- I lii' iay;i^ril mil linrs nl' I lir ;.'iainsnr irlanrmiili'. 'I'lir iioii
is ilaik-ii-il, ap|iai('iil l,\ uclii'iniis limnal ili'. ami nrriiis i'\ ii\ ■.^ lirri'.
llimiirli il isi-niisiili'ialily Irss in animinl I lian I In' Lilain-nnili'. ii s|iii\v>
a Ii'IkIi'Iii'V In arcinniilali' in iri't'irnlai' rhiinps. ( ali'ilr in I'l'i'ipiriil
rair;;<'ii areas is ri'siilnal. Iii'in^ I'lii'mai'lii'il mi li\ ri'> ploi'i-ystalliiii'
silii-a. wliii'li is i'\ iiji'iil 1\ ri'plai'in;; il. Tlii' siliia ini'iiis also in isn
lali'il LTiaiiis spiinklcil I lirmiu'lmiii I lir I'ali'iif. 'riii'si' isnjaiiil '_Mains
an- liki'wisi' i'\ iili'iii ly s nilar\ ami an- ii'plariii^' ll iili-iii'. iliis
Iti'iiiL' <im> III' llii' iiinst iii'ilinai'.x pliriimm-na >>( i|ii> silieilii-al imi nl'
iinii'simii'. as nlis('i\ I'll li\ I li.' w lili':- in I he irnks nl' .\spi'ii. ( nlmailn.'
Till' ii'siiliial I'ali'ili' is iil'li'ii 111 a ;;ri'i'nisli liliii' rnlm-. wlin-h is smiif-
linii's liai'i'l.\ pi'ii'C'pi ililt' ami a^iain v<'i'\ ilci-p. 'I'lii'ii' is I'l'i'ipicnily n
;r|'ailual I lallsil imi I'lnni lllis fnlm- In I lie ilct-p Im'iiW llisli-i.'1'ccM of till-
jjlaiii'niiiii'. Till' u'l'i'i'iiisli-liln Im- siiu:;i<'sis niaiiiraiii'si', an I'icim'iii
ol'ti'li ni'i'iii ;'iiiv' in siiiail aiiiminl in '^lam'miiii'. iiniii wliii'li il iiia>
Iia\i' I II si-paiali-il iluriiiLT lln' ili'i'ninpnsil imi nl' this niiiii'ial: ami a
clii'iniral lest li,\ l>i'. Ililli'lnaml. nl llii' Sni'M'y. slmwcil a I lai-- if
inaiiLiaiii'sc in llii'inck siilliricnl In ai'rminl I'm' I hi' I'nImiiiL:.
Ill lllis lliiii si'i'limi alsn all- scmi ni':;anii- iriiiaiiis nl I'miipliialcil
!>t riii-l nil'. Tlif siniri nil' is liriiii;:hi inin prmiiim'iii'i' li\ i hr ini'irasnl
aimiinil of ^laiii'oiiiii' ami imii <i\i.|i' w hidi ha\r foi'iiii'il in ihrraiials
ami other eaxilies. .Mr. riashi'nril Ueaii. nf ( olnniliia ('nlli'i.'e. has
fMi'iiiiied this seel inn ami has ileleriiiiin'il llie sinielnie as iini|nes-
tioiialil\ thai nf a lishiiiul h.
.\ seel inn nf I he liri;:lll le ' .jasper illlii w Ihi'li the uieeli Inrk p.lsses.
taken niily a lew ilielies frmii l In s| inieli .jllsl ijeseii ImiI. is i-nnipnsei|
'Hull llrnl Xilt lll»t SlII'vi'V MllllliH.itB Sii l" 1'. Itl
'»ii'M"ii r K (ti'iil siirx'y. Vi,l XXXI I .m-i iiiililislinl.
ill
UUi
(il.d
i.cKiv OK riii: vikdn (itii.i) iii-«ri.'i( r. ai.x.ska.
itiri'h mI \fi-v liiii' ;.'i;iln"
c| sili.M uhi.'ii i.- >liiin.'(l llir.iii-l I Willi
i|.. ■,.! .|ci.|.l\ thill llir P"-k i- ii|ph;iiiili<- .'Mil iiliclfi- Itif iiiicni-
iiii'i'ii ,iii'l n
•I P
l«.|>clo|il
li;l\ IIIL
iiiiK' >iniiiiin' lis lliutr
• IfsclllH.I illlilV.-, Willi llu- cM-rplinll 111 lllr n".i< I ll.l I ^'lilll lilf JIIkI
cjiliMii', jiK' l'ifi|in'iii ill lli>' ripi'ks ..r ihi' lkjiiii|iarl s.th's. ami liv ira-
.sMii ..r lli.'ii •.lllHTior li.i|illir>s iirr iimsl <iiiis|)i<'lliills ill ciiMylMiiicnilfH
•Aliicii liiiM' Imtii <icii\i'i| lie. Ill lli.>.<' iiM'ks. riii'V an- imiilf Up
«-,ssciiiiall> "T r*ili<-ii. wliii'li \arii- I'li'iii |«lif i>slalliiii' I" liiirly
i-rv |ilM.i\sialliiic, aiKJ Ih'cuim.s iiCli'ii cliiilri'ilDiiii-, lilnoiis. nr splicni-
liiic W'liiTo 111 i^iiial inck cuiiiaiiiol iiiipiiiil ii'>. ilii'sr iiviirrally
I'l'iiiaiii ill ill- .ias|ii'i-cii(l. MP llial in llif xilira is I iic|iii'iil ly I'miiikI
i-ai'iMPiiai'i'iPiis ami i'la\<'v iiialiTial.
,S. Itisl,.
■/.;
Ajipii:^ >li<'ai /mii'S llii' i'>p('k^> i>l' iIh' l{aiii|pai°l
•iiiN ail' >i'ii liiiii's >li;.'liil\ iiiclaiiinrpliiPM'il ami iirw iiiiiii-nils aro
I III AiiiiTii-iiii tifi'k ami "ill ' N iiknn |{i\cr alxivc .Mis-
lll'llllllD'l
Niiiii (I k vvric i'iill<-<-ii-<l s|i('ciin«'iis ipf -iicli nick, whii-li an- appar-
ciiily xliKlilly iiii'iaiiiiprpliiiM"!, iiiiiuiir. liiH'jiiiiim'cl ■.ciliinciiis. Tlii'V
ail' ilark irri'i'ii in riplmaml ;;rmT'illy liiii' tri-iiiiicil nr apli.inil i"'. Tln-y
<'IIIINI
HionalK' tl
r \i\-\ linch'-tf ividi'il i|iiari/, wiili liiniii ■ rlilmii'; ncra-
ll';r IS (
M
'nn>ii|i'ralil)> luiiriiialiiii' am
•piiliilt
ami specular
iniii is pri'si'iil in pirlcci civsials.
I I KIN IN llli: KAMI'VIM sKltir.s.
Till' ripcks ipI I lir /{iiiiipaii siiii's arc I'lil i)i'<a>iiiimll\ liy lalcr iiilril-
.siiills. TIh' IIiip>.| ' lri|iicMl ilikr nirk is mallil"'. wlliili (ici'iirs in
iiiiniciisr liipilii-. ill 111' l.iiwci- Uaiiipai'ls hflnw M\ muik ( ri't'k. I'iki'H
ipI' yiiiiiiii-piiipliyr.'i ami >>( liuf puipliyry. wliidi arc pinlialdy clnscly
i'i>laii-i| III <iiic aiiipi iici'. Were iiuti'ij al<pii^' i lie ili\ iilc Ih>I ween ( hirki-n
('■'•■rk all)! Ill)- Soitli |''iii'k III' l-'iirtyiiiilf (ii-i'k: anil in tin' saino
vicinil\' ai'i- larir'- piiki'soC (iiiii'-i/.-ilinritoiir yranilf. wliii-li is pntlialily
iMiiiin'iifd ;;ciii'i ii'iilly with llic liiifi i;i'aiiii'il nirks. Dikes iif aplilu
Well' imii'il nil Anii'i'ii-aii (ii'ik ami ai ilic <'ii<i i>( tlic ^°llkllll l''latH
aliiiM' I'lPi I ilainliii: mi Aiiii'iii'iili ( reck is alsii a small iliki' nl' altered
I'lpck. vvliieli appears lip lie iiiii'a laiiipiipphyre.
I'liMHM,.
<>»iii^ III ilie inasHivc iiaiiii'e ipj' I lie rocks ul I he Itainpart scricn
the licilijin^ is p'liei'ally mil iliseerniltlc iirean mil
ili-^iini;!!!
.heil
fi'iiMi the jiiiiiiiii^: ami slicarini.'. .Imljiiiiu I'nnii ihe emlerlx 'iv.r ami
ii\erl\ iiiy riiniiiPi iuiis. liii\M\ er. this series iiiiisl iia\e ' 'eii i niisider-
alil>' I'lililed, altliipiiuli mil iiileiiscly. Sea'' l'''irl lliiiiiliii an pppielii-
iiity was riiiliid til <ili.scr\e the line siratiliealinn, whieh w:i«.: Sliik',
N. ■>" I'..: dip. -'II N'W. I''iiiiher dipw IP ihe ri\cr. in ilie UaniparlM,
strike ill' \. -jr, I-; a
ml a iiip
if |i' >K. Well' nil'
III tll(«
Kfei'ii slates 111 Mymii.k (reel, a '.Irikenl' \. In K. and a dip ul" MO'
•I'l HH )
Tin; UVMrAliT SKI.'IKS.
>!•'.. «cli' iiiitnl. 'riit'M' iiliscrv ill iciiis. t.iUi'ii liii;il Iii-i- « illi tin- .tlli-
lilili- i>( tin- liiiii'Hliiiii'> ami >lialc» « liirh ".iiitimmI iIh- U.iiii|iai'; -iTics
HiiiiH' disliilH'i' lii'liiw MviicHik (n-ck. serin ii> slmu ihal tin- iMi'ks
liaxi' n feudal rmitlicasl >liiki' ami a sdiii lica-.! <li|i in iIk' l.nwi-r
|{ani|iiii°ls.
.KilNTS.
At AimM'ican ( ri'i'k cuii^iilcialilf JuiiiliriL' wa- iimIciI. t iin- |iio-
iiiium-i'ii sci i> iicai'l> litii'i/iiiiial. wliilc aiiollit'i' >ii'jki-« \. ii"! K. aii<l
ilips 7'i NW. Abiivc l''iii" llaiiilin iirniiiiiMiritl \i-rtii-al .julnliii;;
Nifiki's N. l'"i N\ . , ami sunn' disianci' lii-lnw l''(irt lliiiiiliii iiian\ jmIiiIs
anil -liii-sni'lai't's, slrikini: iiniili ami mhiiIi ami ili|i|>nii; '<>< SW..
Were nulcil. AIm>\<' IIi'>s Crei'k. jniiil iiitr w il Ii a >i nki- nf N. jn |.;
ami a ilip III' il"i SI!, was mdi'il. < 'n M\ ninik ( rt-rk at (lilVci-ciil Im-ali-
lio, iiiily a mile "If su a pari, was wen juintiii;; w iili I lie fullnw niu alii-
liiilcs: slriki' N. s"p !•"... >lip sii SK.; sirjke N. In !■'... ilip s" SK.;
Nlriko N. 'la W. ilip '.'n N'l-'.. 'I'Ih' jninis at llu'sc (lilTereeii plaei-s in
widely srpai'iilt'd pailsuj' ilie iCampa;! series show no iiiiirnrmii v in
attitude and Hii^(:;<>st im edmiriMii cause.
slII.AI: /(INKS.
The shear /.nties are inliniali'iv euniieeled «;lli llie juiiits, and are,
ill lael. esselil iaily a series 111 parallel Juinls, se! \ii\ I'liise liiueliier,
alon^ wlliell tlieri' has lieell s.iiiie imiNenielll III' sllppini: 111 the iiH-ks.
prndiK-iiit; jiieal alieijiiiim. The inek aliinu' the shear /uiie is jien-
craii.N sninewlial eriished i>r sirelelied. and nielaimirphie ini'ii'rals are
siiniel ilnes devejiipeil nil a Hiiiall seille. Mule Inipiirlalil ehaii;;e>are
\vriiii;;lii li\ Ihe ill! riidiietion <>r xemip'iiiiiis inalerials li\ waters whii-Ii
iind eniiM'tiient I'haiinels almit.' these /nnes. IJy the aeiimi cif iliese
waters tile n-ek is iri'iicrally mure or less silieitjed. and ihere isoften
liepiisiliiin 111' iiM'lallie sulphides.
vi;iNs.
N'eiiis iif ipiarl/ and eiilfile are Ireipieiitly fmi id. esp«Mially alonu
Hliear /.lines, where Ihey are t'nrmed ill llle ere\ iees let'l 1>\ Ihe nni\e-
lllellls ill Ihe Inek. Tin V ale i;elierall> linlirnkeli. sinee llii'yhaM'
flirnied Slllisei|llelll In llle shearing:. Oil l.iltle MviiiHik ( reek a vein
of pure w hile i|uaii/ i; iVei wide w as nnled, wliieli appeared to Im- per-
sisleiit and 'Nliieh was said In \ield L'nid III! paiiiiini;, alllmnudi niiiii>
appeared in nlllr'rn|i.
\I1K 111- I hi: K WlI'Vlil sKKlKs
I tn l''nrt \ mile ( reek near {''raiiklln < liileh llieUampari meks appear
Ik nvi'i'lii' iiiniiodialidy ihe |''iiri\ mile series. This is the niily plai'i'
where the JKIietinll nf llle Uainpai't series with the illiderl\i ".r I'nrnia-
tiolls has lieell )iiisel'\eii. Iielnw .Mviiiink (reek the itH'ks nl' .hJH
1(!K (ii'.oLiMiN or TiiF- vi'KoN (;in.i) nisi'Kirr, ai.aska.
scl-ii". ,i|i|ir;ir Ici Im- i|i|i'c|I>- ini'll:iill li.\ rnif-;.'r;iilicc|, ciIIiMI r,i rliollJl-
II'. liiiir-idii.'s ,iimI -1i,iI''>. wliic-li iMirv |ilaiii i<'Mi,iiii> >lly:^r^•^*l iiiu
I»i'\ci|li;iri ML'"' 'Ml llli\llkilll iili,i\r ( ilcli- ( il\ till' l{illn|l,l|-| liil'ks
air -ucc Ii'il li\ |iii)liiil>l\ ip\ i-ilv iiiir liiiii'>liiiics ami .|iali'> >iiiiilai' In
lliiiM' jii^l iiii'iil loiic'il. In sui I' llii'M' liiiii'slipin'.-. all' chaiartciiNl ic
( ailicpiiili'i-nii-. IiisnIU \\ ,. max iliiii'lnii- cuiiiIimIc thai tiif iiifk> ul'
lliis M'iii-> arv vi)iiriL:i r I liaii llii' I'ml \ iiiilc sciio ainl njili'i- 1 liaii I lie
olJH'i' I'liiiiial i('ii> vv liiili "ill lie iIi'mtIImmI. Tiir iiili'iiial si nirl iiit" ol'
fill' nicks llii'iiisi'lvrs >liin\s ''Ifailv thai liii-.\ aii' yiiim<,'ri- lliaii 1ln'
Furl villi Ic Idrks, I'lir i'\ clI \\ lull I lie 1 Wn st-rics orclir ill I lie same Iculiin,
as CHI III!' Suiilli l''iirk III' I'lirl \ iiiili' ( ffck. tin' I'mlyiiiili' scries vjiuws
the result-. Ill iiicat cli-l iiiiiaiicc^. wliicli liaxciinl atVcclccl the rucks
III' the |{aiii[iai'i series, ami » liieli ilierelore i iirrcil prcx imis tu I heir
<ic|iiisil iipli. 'I'liese ilist lirliaiices are lliailil'ested ill tlieiililer rucks liy
Ilic |i|imIi|cI idli 111' hiijllly c'rysti.llilic schist s. I he riiriiiat imi lit' e\l rcliiely
ahiiiiilaiit i|iiarl/ veins, ami uther |ihemiiiieiia which are waiitiiij^ ur
are (lev elii|iei| mi a iiiiieh siiialler scale in the |{aiii|iarl series. Oii lhi>
ulher liaml. the I'lniiiat imis « liich will he cuiisiiiereil later shii« suine-
whal los ilynaniic iii>i iirliance than ilu the Kaiiipart rucks.
Ill a s|iiciiiii'n liiiiii ilie lfaiii|iart series lielnw Mymiok (leek, mi
the ^ llkmi. sectimis 111' iiii'anic liniljcs x\ clc miliceil ill Ihill scellctll,
which «iic iilentiHeil by Ml. liaslil'mil I >ean. ul' ( iiliiiiiliia < '(illcire, as
lisli teeth, lint no iiimc >|ici-ilic ilelcnninal imi i-aii lie iiiaile. 'I'liese
ale the miU I'lissil reiiiain-. Imiiiil.
Kl iiNiiMli tMIMiKTANCK
■j'lic rucks ill' this series .nc charactcri/eil tliiuiinjiuiit liy ureal
liasiciiN. The ilialiases cmitaiii a laiu'e |iru|Mirl imi uT iiliu^eiimiN
siil|ihii|es. am! ul iruii ami uihci metals as cuiii|imiciit cleit:eiils uf
aiiiiilc. uli\ inc. ami uther hisilicaics. In the lulls, which make up a
lame prupuriimi ul the rucks, these iiialerials arc sc|iaralcil ami leii-
ileied espcci.illv lialilc til I Icciiin pi islt lull : al'tcrwaril I he re irraii;;e-
iient 111' the cmiipuiieiit clciiieiits I'lilluws Hat iirall.x . ami Ilu cunceli-
Iratimi lit the metals in I'av m. l>le lucalil ies must lie luoked I'ui-. Siidi
lucalities are alVmileil l>\ shear /mies. which may ruriii chaniiels I'ur
walers licarini; mei.illie sulniiuiis ilcri\ci| I r Ilie ilccmiipuseil ilia-
liases ,'inil t nil's, ami aloni; which these metals ma.\ lie ilepusileij
iimlci pruper cumliiimis. .Man.v ul these iiiiiierali/.cil shear /.mics
'111 \V II Hull. Ill iwi;. ri.pMil.il Am .lnui- s,i . thir.l ~..i-i,.. V.-l ,\"I.V. p '.m. ilinlliu,, ■■.juHt
iil>..\ III. Kiiminii u. )»Oilil.H ,1 Xliimiiii hnii'Hi..n.. »iili it. .Imm. icrMir ii.««iK Nc, imilirr
iiic'iitioii I. iimclc Thf iB-l.l.l.-s fcfi.fi-iMl I., Ilia) hiivi' Ibcii derived ii t|„. Itaiii|>iiri .■■i-|i.,.
fcrlhc-s,. III'.' the iiiily r.n'le. c'xii.i,i.il ul,,!,,; tlic > iikicii 111 11)1' I.H'ulity name it .Micnc tlil-. tin-
Hic'i llc.w. l..r wvral Imiiclr.'il inii, s ilii'..iiuli .|,'ii.,.it. .,| '.ili. win, i,.„' ,„' ,„, , x .„||,'|',,|,.
Intel Iciulclc'cl with the'..- Milt, arc ..elll.'llllie., untVc'l-e M'hi. h ar.'. h..tt'l'\ Cr llll.cle' up ,l||||e»t C'Xi 111
■lllcly eirillllU'l.! IM'1,1,1,.'. rilC cl.'I'llUli r the' | i.'l it lie llli'll t |e ,I1.'C | liV Hall Im t llC'I'de ,|-,. pfe ill
ttlily licit fi'ciiii thc'cc- (ji'iiv. I- aiicl wliilc tlii' nicagiiii.'.. .,f tlie- liir<irmail>in i- .in li thai ii..eiiii.
c'lci.l..Ile'UIl li-sarc'lvcll'llVlM (!'. j V.'l.ccllt'lklilHil t,i(tl'tlllM' witli the ..vide- all c-llcl V lllcilluht
fc.iMai'.l t.. .tieewilini the H,'iiii|cuil -c'Hc- is 'ilelc'i Iliaii Ihc De'veehinn unci <apli..iiil.Te.uK. wi-
nmy lec' .luntill.il In .ei.p.'.tlm{ a Slliinan nuc tur ii
Ilir. TAHKANDIT S|:i;li:s.
ii;:*
tS.'t
im
liiiM' liccii (iltsci'Vi'il. lull lliii> I'iir a^iv-. ^Imw ,,\\\\ iiiiii|i.iiiin\ il\
iiiNi;;iiiti<-aiil aiiiiiiinl^ ol' i^nlil .iinl ■•IKi'i': in iIh' 11111111'. huwiv ir.
|)rcililiil>li' "Tc (IcpMsils iiiiiN \i'i\ liUi'ly !»• rciiiinl
i'i;i:\ icii s \(ii|.>.
Mr. I{. it. Mc( iinncll makes ijiciiiidii of ili|., -.itIi's ji> tollnw-. in
siimiiijii'i/.iii;r 'III' cr^ >ialliiic' ■-i'lii>i> \vi>si di'ihi' Kuc^ky Muiiniain--
.Miiiii; till' riisli'iii imIki' nl' llic (•ry?<t:illiiii' ln'lt tin' lucks iiii' iliariu'lcri/.ril liy 11
jjiiiiTiil Krf"'"i"*li I'olor iiiicl nmsist liir^'ily i>t iilliTcd viilimiii- rock*. Tln' must
iiiipcirluiit variety i» a .-ilii'arcd ami alti'icil uri'eiiisli (|nart/.iwi' srliist. With tlii-.
ari' iiss(Kiato<l (^rccnisli ililnrili-lii'iiriii;; schists, Instrciis iiiirn schists, ilinhascs.
anil si'riK'iiliiU's. The schistH an' iiilcrlH'iMccl with iwca.sinnnl haiuls of slat, s and
crystalliiio linuistoncs. ami arc Imikcn llirnni,'h in iijany jilaccs l.y iixmuns mini-
Mions.
I»r. (J. .M. Dawsiiii -' lia- ihpiciI ijialiasi's. <'ciiij.'l(iiiii'i;iii's, MiLriMiieN,
ami iiitcrlicilili'il liincslcpin-. al \aiinii> |iiiiiils almii; 1 he l.i'Wis KJNcr
ailiiNC its jdlicl jiill Willi till' I'i'lly. ( cil mill:; llic Icic'ks ;|ln|l;^ the
I.i'Wcs Ileal llie jiiiietiiin with llie jiiv; SalllKPli l{l\c|-. he urili's:
FrDHi the few e.\iiiisurt's which ec( nr cm that |cart cit the Lewes whic h cats
across the Seininow Mills the rani{c> wcnild apiii^ar tec he ocniiicisi'il ccf ({ri'eiiish.
altered voU-anic rcuks, prolialily diaha.si'. iiilerliedded with ;.'ray 01 whitish mar
llie. Hcicks icf this character life those which have siipiilied the iicilc'rial tor the
cccn:;li)mera(es clescrilii'd licl'iire c)). IKdii. ancl are evidc'iitiv iiinch cc'.chr lican
these and clcmhlless refeialile to the Paleozoic .
THE TAHKANUIT SKRIKS
I'KKI.IMlNAin s|A jKMIAr.
rinler llie iiaiiie Talikaiicjil series lias liec>n elassiiiod .1 scTio cil
while cir ;rray liinesloiies alleriial iiiLr uilli imiIichi.icichis slijijo aiicl
MillM'l lilies willl ecii|e;lciinelale-. 'I'llis clireellv iiverlic's the |{ain|iail
.series ami IIIHlellie^ I lie .Missinli (reek series, wli ieli will lie cleseli liec |
I; ler. Ill this scries have been rmiml e;i((Ml Ipiiei- < atdiiitiileroiis I'cis-
,sils ami |ilaiil rciiiaiiis w liiidi ace picdtaldy nl' l>e\ cmiaii .'ii.re. lint llie
llniils 111' iieiilciLrieal 1 iiiie as^ietii>il ici ii in litis idassilieal imi are mil
illlelnleil Ici he clelliiile The name lallkallilil is taken rniin the
'lalikaiiilil |{i\er. uliicdi etilels lli.- \ iikini m>arllie jnealilx where
rplicr ( ailiciiiileniiis |'ci>-.iU arc ' iitml in u liile cm ysl a lli tie lita>fM>»llf!s.
hlsTlillU TIciS Wji c,|:\|,|; \|. iMirx IMI'lliiN.
ii\ nil-, ^l isccs Miccvi, c 111' ; 1 ■ rrv.
Al llic' imiiilli ccT Missiciii r k are licijcl eliiVs c-cniNi^i in- cd' lila(d<
NJiales Willi thitl'lli clileil sainlsliines miil liniesl.nies. uhieli will lie
ileselilieii as llie .Missinli (reek series. These are civerlaili ralllier
I .\tcic. Il.-pl 11...' Kill lll-t Scii-\..\ rmiii.l.i. Isss su. iic.«- «..n.'- Vc.l IV.]. |:||i
'A:ili Hc'i.t II. ."I N..' Ili-I Scii-v..\ c'liim.lci |ssT ««, iievv- ....i-i,.,. \',.| III I'liri 1 i. IMIl
^'!
i ! \
170 (ir.Mi.iM.v i)\- iiii; MKiiN (iui.n nisi kki, ai.vska.
(low II liy lii'jixy ripiiu'liiiiicralf*. sluilfs. iiii'l >iiii<l«lciiii'~. cjiii \ iiitr ;iliiiii-
(Imit plaiil iiMiiailix. tin- lalln lM'l(iii;;iii;: Id llir l\<iiai M'iii'>. Tin'
iiiiiIitIn ill!,' -.lialN iiM'ks allfiiiali' in liainK^hli ll \ i'il\ iiiir ruii-
;,'liiiiicialir rciiiiialiuii iicmiIn In I ln' 'ralikiiiiilil l{i\<'i'. wlicii' aiiulliiT
fill iiialini ii>i>l iiiir 111' lna\ \ lM(l-.iir |iiiir w liilr it\ >lalliiii' liiiii'>li(iic,
"I'al lii'iiiiv' .\ I'llii^v nil i'\ jiipxil Miilai'i's, I'liiiics ill.
Tlii'M' « liili' (Mvsialliiic liiiir>liiiirs i'liaii;.'c iiii" ;,'i'a.\ , I liiiilicililcil
liiiii'>tiiiii-s, ami alli'i'lialt' " illi I mm Is nf sliali'sainl r(iii;rl(MiiiTalc«,. 'I'lin
rnii;.'|uiiifrat<'s riiiitaiii pflililrs iiC },'i'ay. «liili'. lilark, ami cspiTialiy
fiici'ii c'lifil. « liicli is si Ml i la r to Ilia I nhscrv nl in I lit- |{aiii|iai't rucks,
ami sii si|i.'L.'c>l> <li'i-i\aliiiii riuiii llial scries
III line jiicaiily where eaicriii simly was iiiade ili iiu'liiineiaii's
I iiic calcarciiiis, ami mi |ia--s jriailiially iiiln lie' uliilc i ryslallilic
liniestiiiic: ami Iml li 1 lie ealcaremis eiiiiirliinierale ami I lie |iiire iiiarlil*'
are llltrllly riissilirermis. The fii>sils eolleeleil Were iilelllilieil as
( ailiiinil'i'iiiiis liy Mr. ( liarle-. Silnieherl. uliu iiiade ilio rnlliiwinji
IT|»iirI, aililressei! In llie ! >i reel iir :
In roKiiril Im 111!' fos-iils si'iit tn im- liy Mr. .1. I",. S|iiirr, aii'l (nllicleil 1j\ lii- imrty
iin till' YiikdM Kiver aliiivi' t ircle ( 'ity. .\l;i-<l<ii. I res|iectriilly iijinil 111" r"lln\viiij{:
Tile iiillci linn is an I'.xcrlli lit eiie. audi- the lu^i (•ulliilion i.t ( 'iirlKiiiirirciii»
fiiK.«i!s (rem Aht-ka in llie I'niliil St.iti-. N'alinnal .Mnsciini. The ai,'e nl' the*' fos-
.•*ilM is iiniiii.'<>akal>ly Cai liiinifiruns. iiml ^-iin r iin rharailerislic Lnwir I'arlion-
it'iToiis njH'cics lire iiicsent i infer I his fatnia to he nf I'lpi r < arhiiiiifi'roii.s nu>:
This iiillectii'ii nlsii inilieated ihai the Yiikeii i rirli'inifenms is nmri' chisely
ri'lateil In the N'evaila l'|i|iir < 'arliniiifirniis than infither the < 'alifnniia or Min-
sissijiiii Valley faunas. Tlu' Viiknii, Xevaihi. an 1 Mississi|i|ii faunas ii|i)ii'iir to
have iiinre s|iei-ies in coniniiin tii.in any of tln»e with that nf Northern Ciiliforniii.
The fnllnwinif is a li-t nf the species;
.\ni|ile.\n-'r .Vjipareiilly r-'laled tn \. /aphieniilmniis.
I'riKliieliis niiillisirialns Meek.
Proiliiriiis seinirelienlalns Marliii.
Priiiln. tiis piinetatiisvariii\
I*roilu(tiis hin;.Mspiiiiis Siw. I hy,
Prnilii.tMs Inimisiiinns Siwerhj .■
r'rn.iiietiis like Imoneiisis. lint nineli hlrijer, ('{. l\ iimlaliis nefraneo.
Spirifir n. »p. It ha,sUsnrares| nlalinnsliipin S. senliiniis Mirk. Init iliffcrs
in havin^,' more jJlcitioiis arranK'il in ilistincl Iniiidlr.
Avii'iihilxfteii s{>, uiiilot.
Tlicsc CarlMHiii'cfttns nicks arc >nciitl.\ Iml mil liiicii.scly I'dlilcd, liii«
pii<'aliiiiis Ileitis; 111" aliiiiil (lie same ili>;;icc III' iiiiciisiiy as III llic iixcr-
InIii;; ciiiie|,iiiicraies ami shales lictwccii llie TahkaiHlil Hivcr and
Mi.ssinll Click. Tile I'lissil plaills lliilll llicseii\cr|,t |( n ijlUgliiliiciUlcH
'*«"'"ii I" I'l'- '•>'• >''ii">- ill Hie Kueciii' pr|'iiii|. illlll i|| ii nj|HU s I tli|| Hut
imisi iif ilic rohiiiii; whicli lias alVccicil In iieiiily I ic si|iiii> ilcirrco
all the rdriiialiiiiis riuin ih,. K ,„. „s far i|ii»|| j|s |j|i< I iliiliill-
ircriMis wasci)ihparali\cl.\ icecni—eeriaiiily |HiKl-|*;m'Mll»'. '\'\i\H I'll (■
I'lusidii rccci\es siippiiri lr ilic facl tlialllic lii|i(iiihili|i> l|llni|tr|l.
(Mil ililsdistrici sliiiwsil vci'y ylusc ivlalioii lu i|ic sliiieii|ii.. In siiintt
Ml Ull I
1
iiir. lAiiKANnrr si'.iiii>
|iliHTS f<ill(i\viii;r il r;iillit'iill\ l''i;.'. l'.Ms,i |iliui.ii.'i-u|.|i cil' 1 lie ( ai Ki^li
iri'i'iiii> I'lK'ks nil llii- ^ iiUiiii iiiar till' riihk.'iiiilil ItJM'i. <i|i{iii>iti' ilii
spill \\ Ih'It I III' I'li^sils VMTi' i-iilli'i'li-)|. A liiiijul liaiiil 111' « hill' i'i\ -.liil
liiir liiiirsliiiii' niakt's llir st rilcliirt' ciiiisiiii-iHuiv rrmii a ili*laiii'i>. ami
I III' I'lililiii^' lull I ail antii'liiii' ami >viii'liiii' i- hIisitx alili' In i ln' jiiii iiri'.
il is alsii si'i'ii thai llir aniii'liiii I'ui'iiis a lilll ami iIh' sviii-liiii' a val-
ley, I in- 11 III lis 111' 1 1 11 'SI' 1i)|)(ij;ra|iliii' Tea In res em res|iiiii,||ii;; el.i>el\ in
tllC limits III' till' I'nills. Ill this ea-e lllele ha> lleell lln | il'ni'i ill ||i | ein-
hIiiII silli-e till' I'niilili;;.
Iiclnw the 'ralikaiiilit Uiver Ilien iiie in ealeaiemis ami earlm-
IIIH'enlls shilli'S ami t llin-liiddi'il lillieslnlles, uliieli ale |iiiilialil \ In In-
assi;riieil In the saint' si'rii"> as 'he rneks illimeiliali'lv lielnw Missinii
(leek. 'I'lli'si' rucks enlltilPle ii.lleln|i|iili:.' ainli;; t he ri\ el . allillial iliu'
ill liamis «ilh I he enliiiinliierales. samlslnlies, ami ;riil'> lielnllLrili;,' in
the series which has lieeli linteil as nxeriyiii^ the shales lielweeii Mis-
sion (reck ami the Tahkamlit JiiM'i', as I'ai' as the .iiiiietinii nf the
Cliarlic Hiver with the Viikmi. Near this pnint there cmiie in ;rrav
ami ilark-liliit' liiiieslniies nl' ilistiiiclly nide" ap|iearaiice: ilie-.e are
soiiiclinii's (lark-lilue nr ilaik-;rra> ami enarsely crysialline. Inii are
usually very !iiii'-y:raiiieil nr aphaiiiiie ami iira.\ nr iieailx lilack. the
cnlnr lieilll, line lar;;i'ly tn the presence nl' ea rlinliacenUs inalei ial. 'I' he
cai'linliaecnlis li liiestnlies lieciilne t hili-lieilileil ami pa^>> ililn caleareniis
ami carliiiliaceniis shales. The natural irra> nr lilaek cnlm- nl' ihi'
I'rcsii ruck ln'cnint's in places yellnw-lirnwii rrniii iriiii riisi, whieh is
(Icrivi'il rrnin the (|i'cnni|insitinll nl' pyrile; this pyrile is ilisseininateil
in t iiiy crystals nr nut-like enncrei inns, 'i'liesc rneks miii-mp I'nr .in
nr III miles all >li;,M he N'llk I a lieliiw Charlie |{i\ er. .^1 I he eastern end
111' the cNpnsure iinpeirecl I'lissi Is were I'niind ill rather inassi\e ^'lay
lillli'Stnlle, lillt llnlie '^iind elinl|e;h I'nr idelit ilieal inn . Snme .IHiir l<l
miles alinVi' ('il'i'le ( ily these rneks ari' ■.lleeeeiled l.y llle Incks nf the
Itaiiipai't serii's, already descrilied.
Ili.l.nw MVVnnK ( IlKKK.
,\l>i>llt IS nr Jll miles iieliiw the niniilh nf Mymiiik (reek, nil the
^'ukiili. the rucks nl' I he IJ.iniparl series are siieceeded li\ ;;iay lillm.
jrr.iphie liniestnne, u hicli ill places lias I he appearance nf li,i\ ini: 1 n
fnssilil'crnus; liiit the inck has liecii sn kMcaded liy d,\ iiaiiiic act imi
that tlie I'nssils arc iini ^ni/alilc 'I' he re are niiiiiy sean.-^ nf iin\ ac-
illllc nr liiic-irrained ipiart/iti . which slinw liy their separ.ilinn and
breccia I inn the ninMiiiciiis w hi. 'h lia\c taken pl.ice. (Sec li::. 'i. p. I Tu'. )
Tiicse liineslnlles alleriiale W il 11 carlinlia lis slates, u hich are siillle-
lillli's schistose ami K''»|i'i>I<''< the less alte'.ed nl" these carry iiidi.s-
iUll-i |tlil(if reiiiains. Sniiie if these Were siiliiiiiileil In Mr. ha'id
^\'llile, nl' (he Siirvi'y, who made the I'nllnw iny repnri :
unci piiilM ii'iiiaiiis. .-'nine i i i imvm
^\'llile, nl' (he Siirvi'y, who made the „ ,. ,
I liiive carefully csiiliillicil (lie tliri'i' I'nik'nniits ynii ir.in.Hiiiil in i,'rii|iliitic sluf
f|(i(ll (lie Viiknll Uiv IT, ill (iiiliK I'l'lnw- Myiiiupli Ci I,, 'rinie cm ln' m. il..ul,i
Hull (lid rt'liliiitiH lire nrtfiMiK'. mill, wliilo iliiy iir" luii iilj.'.iiliii'ly cmu KimririiUji
' '
I7"_' (ii:iil.()(iV (If- TKI. VIKON (iol.I) nisTKKT. ALASKA.
il''liriiiitmliU'. lliiTi' is riHiiii fur liiit litlli- cl.mlit lliat tiny loprixiit pl.-iiit Iniif-
iii'iitx. Tlii'v •"•iiii to !"■ niiiiiiiit <if vii-riiLir |iUiiils
I mIhiIiM say tlipy iiiiu'lit 1>« n'filalili' t" l'-ilo|iliyiiih, nr inpssibly wiiiH' -li'iidiT
ft'rii riirliiHi".. If till' fiirimr. iImv iiiiitlil
aiivwiii 11' frum llu- liHWiT l)rvi
hiiiii to till' Ldwit I 'ailioiiifrrimH i iiii'lii-ivi- > Knuii their (iiu'atii/.atimi \vc may
coiiil It'll' that tlii'y ari'|iriilialily ii"t nliliT than tin- Di'Vuiiiaii. Such fni'-'iiii'iitsiirt".
Ill k'i'iM'ral, III"!'!' I'liiiiiiiiiii ill the Miililh' iiiul I'lijH'r |)i'voiiian: ami I iiiori' tliiiii
half i'.\|i<-rt that the ili-^'uvcry nf aiMitimial ami iiiiiri' (*>iiii|ilrtc inati'rial will imli-
cati' all iiui' ill that ri'tfinii "f thf ({•'"li't.'ical luliiiiiii.
Tiiiiiiiii'h ri'liiiiiri' ■•h'liil'l mil. Iiowi'mt, !"■ iilac'il "ii tl hsi-uri fraKiiiriits in
haml. Mim ii tln'y ai-i' hanlly u'l'mTirnlly i'lriititialiU'. still 1i">n Hpi'iillcally sn: ami
whili' I inlrrpn't Iroiii iIu'Iii a lii<-aiiiiiL; a> .iIi'iM' .-tali'il, it i^ <|iiili' pi'Msilili' that
Kl'. '.I Kiii'iiillhif ill ii|ihaliili" liiii.-t"! f TiilikiilMlit -.-n. -, I..
•\V4'i' Itiiinpiirts
aiMitiuiial malirial i whirli is in.i-t In lie dcsiicil i will
lltiratliill of iipllinli. .\iiy
11. ri'ssifnti' a I'niisidfralili'
pri»inii III' opiiiinii as til till- a-cnf lln' fniKiiinits
li'fiiii' nil' is liazanliiiis. thiiin,'h tiny su-^r.^t Miihll.' ..r Tjipir D.'vnniaii I
I iiil.r llii' iiiii'i'iiM'ii|ii' ilii' liincsliiiH' ii|i|M'.iis III Ih' \ry\ liiu' ;:r,iiin'ii
aiiil.'i)ni|.ai;ili\.|y|iuivjiki'lli.',i,'iii\lilliui;i;i|,|ii,'liiiii'sl.iii('.si|(-sri'ilir.l
•low llii' Cliailii' I{i\(
r
Id
riiic-yiaiiii'il i|iiair/il('.s .ii- iiii\ai'iil
K' i|iiarl/. M'anis mii' sci'ti tiiii'i'dscuiiicjiliy
III';
ill iiiiiiu:li
III till'
spi'i-iiiii'ii llii-y nt'ii'ii Iia\i' lilt' a|i|ii'aiaii<M' nj' ■^vn\ clicii. ]
of Ihi' riii'lx llicsi- iiovarillili'S an- sli
(till
II |inl'l|ii|is
I'iiii'il. ami Miiiii'iliiM'.s I icinnlitc,
s llii'lailiiil'jiliir
!ii '" Iioi'IiIiIi'IkIi', ami liiniiii 1i,im' Ih'I'ii ili'M'lup.'.l
liiiiKTals. oili.iM'aiii.siir li;;lil-;:ri'.'iiapliaiiilii'i-.i<'k.wliii.|i,ii-,'Mi''ail\
iiU.' 111.' iio\a.'ulil..s ill 111,, han.l sp...'iiii.'ii, aii' m'cii iiini.'r ih,. nii.'f.'.-
si-.ipc III hi' cuiiipaci ciav -slaii'.s.
Till-. TAIIKANDIT SF.IilKrt.
ITS
NKAIt TIIK MKI.iiZIKaKaT UI\ I It.
Nt'iii'Ilii' iiiiMitli of III)' Mclu/.ikiikal HiviT, a Icirality ii!il nImixmi mi
ilic iiia|i ul' till- \'iikiiii Kiilil lii'liU. lull wliirli iiia.\ Im> I'iiimhI um j'U.
\ X X I! anil X X Xl\', llii'ii' iiiiti-i'iipN Ciir m'MmhI lllill•^ lilin'-;.'i-a,\ rixs-
laliiiii' iiiiK'stiiiH' iiiiili'i-iaiii liv Itlai'k slati'. In i!ii> liiiii'>tiiiif ai'<-
lliiii M-anis III' w liiii' iiiaililr. ami llii'mrk Immii Ii\ >iiiall >Ii'iiim'i' veins
III' I'alcili' anil nrrasimially nf i|iiarl/. 'I'lii'ir i>. mhih' Jnini ini,'. IVi--
t|Uriil sliitpin^r, ami sli;:lil shraiint,', <'s|MTiall\ alnn;; lii'ililiin; |ilam'«.:
lint thi-rc is im iiiiiriinn snnIi'Im in Ihc Jniritin;;, nur yi'iicial M'lii>lii>li \ ,
niir any olinT oilier r\ iileiiri' nf ri-;;iiiiial strain^. At llie rasirrn m-
n|i|ii'l' cliil <il' the e.\|iiisilie the l)liie-;;iay liliiesliilies iinli'ni|i. •.Iiikilij;
N. (in K. ami iliiipiii;: I'l Si';,; ami at the west eiul ul' ll \|iiiNni'i>
are the same Jime^tKnes with the same strike, lint iliiipinj; :!ii \\V.
lietVM'ell t liese t«ii espiisnres eiiiiie in the slates. These ineks. 1 hiTe-
fiire. I'liiin a syneiiiie whieh ivpnses liy eriisiiiii the nmlerlyiiii.' slates
lietween the twii liejts iif liiiiestnne.
<|'1!I!KI.AII<IN AM> M iM I'.M I. A I I ' 1! K.
Th
isalreaih ileserilieil heliiw .M\ III ink (reek anil I lliise I PI I ween
(iiele City ami Charlie Uixer lesemlile niie .imil her elusely in lillni-
loirieal eharaeters ami appniximaiely in I he a mini n I nl' iiietaiMnrphisiii
wliieh they liave iiiiiier;fi)iie. lielnw Myiumk Creek the iiieks are
sipiiiew hat inure allereil than aliuve Cirile City. Inn this may lie
aeeiiiinteil I'ur liy the prultaliility that the Uampart Mniiniaiiis. in
whieh the I'nrmer expusiires ueelir, lia\e been snlijeeted tii niiii'M
(lislnrlianee than the le^imis lyin^'- tu the mirth ami In llie smith.
It is III this ilist iirliaiiee that the existen r the iiiiinntains is
pruhiilil.N line. 'I'lie i;ray liniest
lilies ami sliaie
III" Mymiuk ( reek,
imireii\ er, appear tu uxerlie ilireetly the lueks III' the Kamjiai't series,
illile aliiiM' Cirele <'ilv rucks whieli lesellllile I he:
lit liuluL'iealU ar«>
alsii siieeeeileil liy ilie riieks ut' the Uampart series in prulialpjy th«
.same relat imi. 'I'liese nueks, emisistinu: ul' y:ra.\ limestunes ami shales,
mileriip lieluw Charlie IJixcrmi the \'nkun, ami appear tu lie siiceeeileil
farther np the ri\iM' liy white erystalline limestmies with interln'ilileil
shales ami euiiMlumerates, ami these llniesimies earry ( arliuiiiferuns
fossils ., mI. in the lueality lieluw .Myniiuk Creek t he shales assueia ted
with t II ■^y:t\ litliiij^raphie liniestmie earr.\ plant remains wlileh sii^-
^est I) \uniar a;;e. In the rueks imteil near the Melu/ikak.it no fos-
sils wei" luiii I, lull the j,'<'iieral litholoirieal eharaeters uf these roeks
imi tl
ttiit tu which tliev liaxe lieeii iiillilenecil li\ lUnainii
(•iian;res st run^ily sii|j:^fest this ;feiiei'al l)e\iinian-( arliunifermis series.
.Ml these rucks may then he classed toi,'ether as a siiifile series w ilh
siiiiicwhat inderniite limits, uml may he emiv cnieiit ly failed the
Tahkandit sories, from the 'rahkaiMlil l{i\«»r, which i nters llie Vnkim
)
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Photographic
Sciences
Corporation
23 WEST MAIN STREET
WEBSTER, N.Y. 14S>0
(716)872-4503
174 GKOI.OfiV ni- TIIH YUKON (i'HJ) DISTHK T, ALASKA.
iiciir till,' |)l;ici' wiicrr CMrbniiiriToiis lossils were rmiiid. 'I'liis serios
may tliiMi lie (Idiiicd as coiisisliiii;- of liiiu'sloiK'S, SDini'tiiiies wliite,
goiiorally j;i('cii or bhifk, sDiiictiiin'.s cryslalliiiL', often aplianitio or
lilliofiiapliie. Tlio.solimi'stoiii's become tliin-boililod and carboiiaeeons
and alltTiialc with slialcs. 'I'lic white ciyslallino limestones of the
C'ail)i>Miferous above Circle Ci'.y also alleiiiale with beds of eonjrloni-
erate confaininj? chert.
Tile 'I'aiikaiidit rocks overlie the Kamiiart series directly, and the
chert in the eon.ij;loiiierate mentioned above snjis^ests derivation fror\
the roeks of I he Kaiiiparl series, 'riuis an niieonformity, or at, least
nn erosion interval, in .some part of tiie 'i'ahkandit sciies may be
sn.spec1e<l.
The lower limit of this series isthus fairly definite. The upper limit
is not so well marked, but is taken approximately at the bottom of a
series of bhick shales* with interbedded impure samlstones and lime-
stones, which ise.xposedat and below .Mission Creek alon^- the Yukon.
'J'he fossils taken from various points in the Talikaiidit series .show a
ran.ire in a,!j;e from probal)le I'piH'r Carlioiiiferoiis to probable Devo-
nian, liiit tile .series may contain format ions lielongiiig toother jjcriods.
It has no very delinite limit sin point of a}?e, and lias IjeiMi named merely
for tlie elassilication of our very rudimentary knowledfje, and for
convenic'ce in iiiai>i)iii!;'.
OTIIKU AKKAS MAPPEn AS TAIIKANniT KOrKS.
."Mr. 11. (i. .McConnell ' notes that, on tiie J'orciipine, below the niontli
of tlie Sneeor l{iver, tliere outcrop for J.") miles yellowi.sii-weatheiing
limestones wiiicii yield . liri/jni rrliviihivis wilii fray:mentary speeimens
of corals, and wlii<'ii iie refers, in part at least, to the Devonian.
Farther down tlie river, close to tiie edjje of the Yukon Fiats (wliicli
e.xtend u[> the Porciii>ine for a ioiijj: distance), these limestones aro
iuterliedded with dark shales, which .Mr. 31cConneil considers as
l)robai)ly Cretaceous.
3Ir. W. ()f;ilvie^ lias made atraver.se from tiie Yukon up tiicTatondu
Kiver aero.ss to tiie headwaters of tiie I'orcuiiine, and so down to tlie
conllueiice of the I'orcniiine wilii the ilell Itiver. On liiis trip lio
has noted liiat dark siiales, overlain liy liiie-j;;raiiied contriomerates,
occur aloiifT tiie Tatondii for 27 miles from its inontli. At two i)oints
in tills liistauce limestones rise to tiie surface from boueatli liie sliales.
ami in tiie upper part, of tlie valley of tiie Tatondii liie siiales and oon-
glomerates are replaced by tiiese grayish I'aleozoic limestones. Simi-
lar limestones were also met witli all across tlie watorslied sejiarating
tlie Tatondu from tlie Porcnipine, wiiere they form a range of liigh
mountains, and down tlie l'orcu])ine as far as tlie Cathedral roeivS.
.Mr. I. C. Uussell" notes that the crest of the mountains, a few miles
'Ann. Ropt. Gool. Nut. Hist. Survey Omadii. Vul. IV, Sue. U, ii. l:i;i.
«()p. I'it.. 11. i:i».
» Bull, (ii'.il. Sin'. .VmiTicii. Viil. I, p. I.li).
THE MISSION CRKEK SEHIES.
175
iioi'tli of the Yukon, at the intonialional boumlarv, 'Ms fompciMMl nf
coinpael earthy liiiu'Stone in nearly vertical strata, strikiiit;' lU'arly east
and west, couformably with tlie trciul of tiio niountaius.""
THE MISSION CREEK SERIES.
PRELIMINARY STATEMENT.
Stratigraphically above the rocks of the Talikandit series eonio
blacli calcareousor i'eldspathie .sliales, wiiicli allevnale witii tliin biMJs
of impure limestone and witii beds of gray sandsbine. 'i'iicse locUs
aro generally considerably and sometimes intensely folded, and j re
sometimes slightly sheared and altereil, but ordinarily are fresli and
recent in appearance. They sometimes overlap tlu; i-oeks of llie Tali-
kandit serie.s, so that iu at least two localities visited tlicy lie upon
the llanipart series. In both the.se cases the lowest bed of the
younger formation is a conglomerate containing many fragnifnls of
the rock on which it rests. This series has been named from .Mission
Creek, iu the vicinity of which it is well exposed. It is probably, iu
part at least, of Cretaceous age.
DISTRIBUTION AND tiENERAL DESCRIPTION.
NM'OLKOX VXD CUICKEN tHEKKS.
According to the ob.servations of Mr. Schrader, the mouth of Xapo-
leon Creek seems to be nearly on the contact of the iiampart series
with the Fortymile series. Just above the mouth, however, there is
encountered, resting upon these older roeksj a conglomerate, which is
made up at the bottom of jiebbles ranging iu size from mere grains to
a foot iu diameter. These pebbles are subaugular in shape, showing
that they have not traveled far, and among them are fragments of
quarlzite and of vein quartz, probably derived from the IJiich Creek
or Fortymile series; of aplite and porphyry, similai' to the dikes
already mentioned in these older nicks, and of comi)act gray and
green slate, identical with the rocks of the Hamjiart series exposed on
t.ie ridge between Fortymile Ci'eek an<l Chicken Creek, only a few
miles away from this conglomerate. The conglomerate is very firm
and coherent when fresli, so that the pebbles often break before the
cement does. The strike of the rock is X. 2")^ E. and the diii li'i SE.
Farther ui) the creek this conglomerate is overlain eiiiiforiiiably by
coarse gray sandstone and grit, interstratilied with scams of a black
coaly slate carrying plaiit remains, which, however, are so poorly pre-
ser\ed as lobe indeterininable. Above this comes liner sandstone,
slightly interst ratified with coaly slate and striking N. 4'J E., with a
dip of f)0' SE. There is liere considerable sliekensidinganil jointing;
the principal set of joints trend N. 10° AV. and dip 80'^ WW. Higher
up in the series the black carbonaceous shales beenme nioi'e abun-
daut, and contain beds of compact greenish clay-slates, while still
'H
V'^,
Pi
i
I
176 OI'.OI.O(iV OK Tin: YUKhN gold DIS'IIMCT, ALASKA.
lii^'licr M|(cmiifs iirt'imccoiis liMU'sldiic. wliicli is in part iiuinnorized
by coiilucM Willi a ImmIv of dialiasic liasall Fii Iliis iiianiiorizcd Ijinc-
stone tlitTc is a |ii<Hiiiiii'iil jdiiiliii;;. striliiTii;- N. \'.> K. and dii>i>iiij;
■M)" X\V.
Tlic y()iiiij;<T scries, <'iiiisisi iiii; of a '...sal (■(iiifrioiiK'ratc |)assinj,f
upward iiiln samlslouc, jri'its. shales, aii'' iiiiiesloiies. is seen al tlie
tiiDiidi »( the irideh tii resi iilieoiil'ciriiialiiy mi the ohU'r roeks, uf wliieh
fra;;iiieiits are foiiiid in the ciiiiiildiiieiale. In tiie bed dC Napoh'cm
(.'reek the gravels in the bell iiceiipieij b\ the basal eonuloinerale and
inmiediately beluw iliis belt an' rich in placer ^nld, while above this
eoiiiparatively narrow /.(ine thcyai'c entirely bancn and below they
ari' very poor. It is probable, thercl'orc, that 11ic};old isdci'ivcd from
the conirlonicrale. and from t lie l'a<M that this confrloincratc is coiii-
poscil of t'ra;iiiieiils of the older aniifcrons ro<'ks it api)ears that the
gohl fi'oiii these rocks has been concent rate<l in it, so that it is an
ancioid oi- fossil [ilacer.
On ("liiekeii ('ri'ck black, carl, uiaccons, c()nii)acl shales, containing
impure coal seams, form a lari^c i)art of the beil-rock.
Mii-riisriijiif {■hiiriicti rs. — Cnder the microscope the cement of tho
Napoleon Creek coniilomcrale is seen to beesseiit ially like the associ-
ated bedsof jrrit ; both are ma<le n[)of fraii'mciilsof varying siWiOl'toii
iinfriilar ami ill assorted. These frai;ments are of (niart/ and feldspar,
both ]ila_irioelase and orthoclasc, wii li blot it e, often altered to chlorite.
The liiiei' material i nclosinjj;! lie.se jji'i' ins isa calcaroonsand niuseovilic
ajrurcfiate, containinir liny grains of crystalline s]tecnlar iron, which
are often altered in pari to siderite and limonitc. In many ca.ses these
iron minerals arc seen to be <l(>ri\ed from the biotitc in the ])roccss of
its decomposition. The microscope al.so shows tlie shales to be com-
posed of tiny particles of ([iiartz and snbmicroseopic ag^'re.uatcs of
decomposition products, with much carbonaceons material in the l)lat'k
varieties.
IIKI.IW |-ol(TVM!l,i: IKKKK.
On Forty mi 1(> ('reek,alioiil .'i miles above itsnionlh, th(> schists of the
Korlyniile scries are siK'ceeded by black shales and sandsloiies, strik-
ing: east and west and dipjiin^ 111 N. Tlwse rocks are t ra\i'rscd by
shear zones, aloiiji which there has been some mctaniorphism, partly
dynamic, but iiriiicipally aiincous, evidently resullin^.' from w,".;er,s
which have coursed aloiiij these zones. As the result of tl. is action
the rock in the iiiMjihltorl 1 of the shear zones is often somewhat
iniprcfjnated wi.h sulphides, and fre(|iiently small <iuartz veins havo
been loriiied. On Cone IFill, opposite the mouth of Clinton Creek,
one of these altered zones has been exphiitcd for ore. The rock is a
line-;rrained impure limestone, rendered schistose in nai'row belts.
From the alteration of the minerals which have liecii deposiled alon^f
lhe.se belts the outcrop appears dark-red and sometimes ^reen, the red
sri RB]
THE MISSION CREKK SKRIKS.
1
I (
color l)('iii^ i)i'olial>ly (Im- 1o iron and tin' jri'ccti to cliroiiiiiiiii. 'I'ln'
altered rock is said to sliow the presence of precious iiii'tals im assM\-
iiifj, but an assay made In the lalmralory of the Sui\cy sIkiu-. mo
appreciable amount ol' eillier ^old or sil\er.
This rock series is exposed \'vii:u llie|>oinl al::)Vi' uienl ioui'd toliic
month of Forlyniile Creek, and from here <louii ilic ^■ul•;on for alioul
i!."> miles. I''or the wliolc distance tlic lock consisls of IdacU sliaies
alternating' with thin-liedded ,u;ray sandstones and iimestoues. The
beds arc held into broad, open folds, which u:ro\v more pronoiuieed as
one {^oes down tin' ^'ld^oll from the mouth of l'"()rtymili' (feck ami
approaches ncai'ei' the Mammolh Mouniaius. There is also sliulit
faidtiliu'. \'\i!:. HI, .1, showsthe structure of a hiu'li and loiii;' sect ion of
Fiu. til Sl^(■l.■lu•^< (if ilistiii'l.i.il stnitu of Mission n k soi'i,.s.
those bedsexposed in a vertical olill' on the river aboiii lo nnles ludow
Fortymile Post.
These rotdis are cut by occasionid dikes, whicli are irenerally li}fht-
yollow in color. Speciuu'ns of a dike ro<'k collecte(i at the nionlli of
Coal t'reck have been Ibnnd to bo porphyry.
MifVdncopic chiiriirhrs. — The Ihin-beddeil limestones founil near
tlio mouth of !''ortymile Crook, and below thai cri'(d< alonnthe N'ukoii,
are ordinarily dark-n'ray in color, and nndci' the micros<'op(> are seen
to bo made ui) of very small calcite j;ranules with no evident reu'eiu'r-
atiouororystallizatiou. Alonj; the sheared ami altoi'cd zones a short
distance above the month (d' the crock, however, the limestone has
boon [)artly rocrystalli/.od and dolomizol, and the nucroscope shows
the development (d' occasional inetanior[)hio miiu'rals. There are also
18 QEOL, PT ;J 1-
m
J . -!*'
178 GKOI-tXiV OF THK YUKON GOLD DISTRICT, ALASKA.
small niiisscsiif a dark-hnnvii iiiclallic mineral, wliicii arc surrouiuled
by 11 .slif,'ht stain of j^rccii. I'liciiiical tests made liy Df. Ilillehraiid,
ol' tiieSuT'vey, sliow tiiat the (laik-l)i(iwii iiiinei'al is probably chroinito,
ami that the ^fcen .stain which sui't'oiiiids llu'se grains, aud which
gives a .i;eii"fal eoloi- to tli(> foek in the li<'l<l, is due to clii-ominin.
l'"i-oiri tiie !imestoii''s there is a transition to coai'.sc caleai'eoiis shale,
whicli is often dark-gray in color, hiil on oxidation cliangcs to liglit
red. This shale is made iij) cliielly of small dctrital ([nartz grains and
of mica which is also iii'ohalily dctrital.
'I'he sandstcmes wliich arc asso<'iatcd with these thin-bedded limc-
.stoncs and shales arc loi'ally melamoi'iilioscd into ([nartzitcs. In a
spoeiinen of sheared sandstone from Fortyniile Creek, about .'i miles
a1)0vc its month, the alteration has given rise to an abiin(hinc(> of fclty
actiiiolite. 'i'his st)ecimcn is traversed by many parallel fi'acturcs at
riglit angles to the i)lancs of siiearing, and both along these fractures
and along the shearing i)laiies a great deal of iron o.xide has beeu
deposited, whicli gives the Itrowii coloi' to llio rock in Ihc field.
MISSION I i;i;i:k and iii-.i.ow.
About •2i> miles below the mouth of Fortyniile Creek the series
jii.st descril)cd gives way to the J{ampai'l series, but 5 or 10 miles
above Mission Creek the liaiTqiaii .series is again overlain by thin-
bedded black Ol' gray limestones and limy shales whicli seem t(j bo
lithologically like tho.sc exposed l)elow Fortyniile Creek. The plica-
tion of the bods here, however, is much more intense, the strata
being com i)rossed into close folds which are often overthrown. The
sketch in lig. 10, Jl, is from an exposure of these beds on the Yukon
above Mission Creek. It is to be noted that the locality is in the foot-
hills of the sierras which have been called the Mammoth Mountains.
The ineroa.se in the inlcnsily in the folding as one apjiroachcs these
mountains is very mai ked. Although 1he.se rocks are closely folded,
there are no .schists or <iuaitz veins of any importance, and the whole
appearand! of the formation is comparatively recent.
These rocks are continuously exposed to the mouth of Mission
Creek. On American Creek, which is a branch of Mission Creek,
tliere occtir.s, aliout -2 miles above its mouth, the contact of these shaly
rocks with the rocks of the Rampart series. The actual contact was
not observed, but an outcrop a short distance away is of gray shales
with layers of impure coal. I'hese shales strike X. 70 ' \V. and dip 05°
SAV., and overlie more massive dark-gray or dark-green rocks, much
older in appearance. In the bed of the creek were noticed large
bowlders of conglomerate, with a hard limestone cement, containing
pebbles of (luartz and nearly black slate or chert. The size of these
bowlders shows that they must be derived from some point close bj-,
and they are probably from the basal conglomerate of the j-ounger
shaly series, which rests uueonforniably upon the ohler rocks aud
6PIKB.J
THE MISSION CREEK SERIES.
179
corresponds lo the basal oonsjloinciate oli.scrvcd du Xaimlcoii (reck.
Tliis sofios is contimioiisly exposed on llic main .Mission Creek,
nearly to its head, and consists of thin hcd.s of I'lMiulonieratc, black
calcareous shale, thin sandstones, and carbonaceous liniestoui' with
seams of slaty eoal. These rocks are much folded, but are only
locally altered by shearinj,^ Near the junction of .Mi.s.sion Creek
with T\v(!lveinilo Creek the series is overlain uncoiiforinably by
sli}i;]itly tilted coufilomerates and grils with unconsolidated li^'nite
beds. This later .series is probably- late Tertiary.
From the inoulh of .Mission Creek down the Yukon the rocks con-
sist of black shiiles with thin-bedded limestones and sandstones.
These bed.s are intensely folded, but the folds can be continuously
followed in (he vertical cliff sections, for there is veiy little fault iiii,'.
In these cliffs sharp or j^entle anticlines and syiiclines, occasionally
slightly overturned, succeed one another I'apidly, for they are ordi-
narily of nn great magnitude.
About 7 or 8 miles below Mission Creek there come in massive con-
glomerates, containing jH-bbles of small size, which are ai)parcntly
almost exclusively of dilfereut varieties of chert— gray, white, black,
and especially bright-green. The conglomerati' jiasses into samly
argillaceous limestone and into shaly layers, in which are abundant
plant; renuiins. This conglomeratic and plant-bearing formation
appears to overlie the dark shales and thin-bedded limestone and
sandstone which are exposed at Mission Creek ami immediately below.
It has been separated from the ^Mission Creek series, and will be
described later under the head of Kenai sei'ies.
At the locality mentioned abov(^ the conglomerates and leaf beds
occupy a belt several miles wide, below which again come in rocks
like those exposed at ^Mission Creek — mostly black sliaUs ;ind gray
limestones with seams of im])ure clay. The outcrops ar^' yellow in
places from the formation of sulphur on exposed surfaces. Farther
down the conglonu'ratic series comes in again, alternating in broad
belts with the underlying shales. These two series piesent such
marked lithological difTerences that they were classified f-eparately iu)
the field. The fossil leaves which were collected from the U[)per rocks
are stated by Dr. V. II. Knowlton to be evidently Eocene, while Mr.
R. G. 3[cConnell, of the Canadian (ieological Survey, collected a char-
acteristic Lower Cretaceous fossil fi'om the underlying shale series.
In the neighborhood of the Tahkandit River the dark shales and
t 'n-bedded limestoiu;s of the ^lission Creek series are succeeded by
\ lite limestones interbedded with shales and conglomerates. In tlie
limestone abundant fossils were found. These I'ocks have already
been described as pari of the Tahkandit series. No abrii])t break was
noted between the Tahkandit series and the overlying ^Mission Creek
series, for the rocks of both have undergtme about the same slight
amount of alteration, and both are folded in about the same degree.
■, I
«
180
oEiiLOdv or TH1-: ykkox (ioi.it nisTurcT, Alaska.
'J'licri' is ;i iii;irU(Ml lilliolnicical rcscMililiiiici', moreover, for Imtli series
I'oiitaiii siiiiiiiii' (•alciircoiis siiales. anil llie coiitrloinerates of tlie ear-
hoiiil'erniis noted alioveare iijeiitleal in a|i|)earaiiee with I lie (•oiijj:ioni-
erates of tlie Crelaceous and Koeeiic. all lieiiiir eoiiiiiosed of jielihles
wliieli lia\'e the aspeet of i).'in,i;' lariTely derixcd IVoiii tlie roei<s of tlie
|{a]M|)ar( series. So it appears that the .Mission (reek overlies the
'I'alikaiidit with no eiioi'iiious iineoiil'oriiiit.x . and that the rocks of
liotli lliese series lia\'e been left nearly iMidisI iirhed iinlil a eoiiiparii-
1i\-ely recent period, when all were I'oldecl at the same time. The
Yukon J{i\'er, cutlin^r across the folds, now exposes the dilTerent series
ill alternatiiiu' hroad liamls.
."\Ieii'asco|)ically and iMici'osiMjpically the rocks on .Mission Creek and
below resemble closely those at the month of l'"<irtymile (reek. The
tliin-bedded limes'ones of .Mission Creidi are .seen under the micro-
scope lo be made ilii of pure, liiie-irrained calcite or doloniile, willi
carbonaceous material in some parts.
.VIony; shear zones treiiiolite is dcM'loped in this limestone, as in the
liu'estone near the nioiilh of Fortymile (reek. This tremolitie rock
lias H j;reenisli color and a schistos" si riictnre in the hand s|iecinieii.
A green feldspathi<' stale, which is sometimes found, is made up of a
very fine a}j,srre,u:ate of (piart/. and musco\ite, with \eins of calcite.
Fine-grained sandstone, consist inj;- ehielly of small detrital (piartz
{grains, .'itli .some carbonaceous and claye.\' material, and veins of
iibrous <'halee(lonic silica, is common. Other beds are coarser and
more ini|)ure. and are to be classed as mrits. One s[iecinien examined
was made up chiefly of frafiinents of ])laf;ioclase and jiyi'ile, botli
nndoiibliMlly detrital, and both present in larjic amount ; these wore
emlieude(l in a ceinenf which was [larlly calcareous and jiartly a
nu.xture of indeterminable decomposition jiroducts.
KAXniK lilVKK .\NI) VlrLNlTV.
In theneiirhborhood of Katlinl ."Nioiintain, on the Yukon, calcareous
sliales come in as^ain with some thin-bedded blue-«ray limestone.
These beds are clo.sely comi)ressed, often into vertical folds, and are
in places niuoli .jointed and cleaved; occasi(nially there are small, non-
persistent (piarlz veins. Above the Kandik Kiver these beds are suc-
ceeded by {freeii j,n'i'^ sandstones, and conglomerate.s, with coaly seams
and impure plant remains. The beds evidently correspond to the
up[)ercon,irlonieratic series noted fartli"r up the river. A* the Kandik
Kiver closely folded, black calcareous shales and thin-bedded linie-
stoiies afjain ccniie in, exa<'tly like the rocks observeil near Katluil
3Iountain. Farther (hiwu the Yukon, above Charlie River, these
rocks are succeeded by uuissive gray limestones carrying obscure fos-
sils. These limestones have already been described as part of the
Tahkandil series.
I
Jiu
5w 'it
smut.]
THE MISSION CKEKK SEIUES.
181
C'OHUKLATKlN.
'I'lii' iH'<'UiT<'iic('S just (Icscrilicil rrmii Xa]">l('on (rccU. ( liickcn
(.'rt'ck, tlic iiioiitli of l''.irt yiiiilc (reck iiiul hi'lnw. Mission ( iccU iiml
vicinity, and iiciir llic Kamlili Uivcr. arc ail nf nx-lvs liaviii;: similar
litluilDjflcal cliaracters, hciiig composed ol' dark calcareous ami cinlion-
accous slialcs with tliiii-boddc(l impure limestones ami san<lstoHes. and
occasional tliin beds of ;j;i'its and conjrl'>meratcs. Tlie^e rocks cairx
iiii])urc coal seams and i)lan1 remains, wliicli, so I'ar as found, were not
idcntiliable. In all the <lill'erent localities I he I'ocks desi'rihcd haxf
T)(;en considerably' I'olded, but oidy slijflitly faulted, and only locally
have they been sheared, cleavecl. or metamorphosed. In all these i ks
vi'ins of t|uart/. and ealcitc are bnind, but they are usually small and
iioniMM'sisleiit, and do not form a distinniiisliiiiL; feature of the rocks.
AVhorever the liasi' of these beds was obsei\('(l, as on Napoli'on and
American creeks, there has been a basal conglomerate conlainini;
])ebbles of the rocks on winch it rests. On Napoleon (reek this con-
glomerate rests nnconformably on the I'oeks of the i{ampart series
and of the l''or1yinile series: oii American Creek it rests unconl'orm-
ablv (m the Hampart series, i.elow tin' '{'ahkandit Hi\er, ho\vi'\cr,
and also Ixdow the Kaiidik River, the series which at ^li.ssion Creek
vests ui)on the rocks of the liampart series is underlain by the Tah-
kaiidil series, with no appearam'o of great unconformity. This
shows thai the .'^lission Creek series must overlap Ihi' edge ot' the
1'ahkandil series, ami some slight unconforinity is probable. This
iiiiconformily is also hinted at by the congloiiierales occurring in this
and in the underlying Tahkaiulit series.
Uolow Mission ('re(d< the shale series is o\-erlain bya conglomeralic
series carrying abundant plant remains. Above and below the Kan-
dik liiver shales and limestones having the same lithological charac-
ters as the Mission Creek rocks a., also overlain by tin • plant -bearing
conglomeratic series. Tlii correlation of the rocks in the \icinily of
]\rission Creek and those in the lu'ighborhood of the Tahkandit Uiver
is, llu'ri'fore, strongly snpiKU'led by lithologie, dynatni<', ami especially
by .straligraphic evidence.
Tlie strata at the mouth of I'orlymile Creek and below .•ire sep-
arated from those near ^[ission Creek b.\' a belt of older rocks, which
is probably maiidy referable to the Kamparl scries. Uetwccn th(^
rocks at these two localities, however, the lithological resemblance is
grout, and they have both bee!i alVected to nearly th- same e.\t. nt by
dynandc action. On P'orlynule Cre(d<, .just aboxe the mouth, there
appearslo have been sli.ghtly greater alleration than is usually shown
in the roid<s near .'\Iissiou Creek, but this is jiiobably due to local
shearing, which gives the formation in iilaces an older appcaraiK'c
than have most of the rocks corrcdalcd with it. On Coal Creek, how-
over, al )nl 1- miles above its mouth, are bmml beds of hard lignitic
K i'
T^^'
•li»
i I'
1 1
I
n k
ftyl
- !'
^
1«2 GF.OMKiV Ol- Tin: VIKoN OOI.IJ district, ALASKA.
I8
coal, with hrilliiiMt luster and iMindioiilal rracturo ami cDiitaiiimg
graiiisof amber. ( oal i>( Iliis iialm-e isofton found iiitho upper coii-
tili.iiieralie series, and is not. sofarasohserved. found in thelowor sluilo
a)id earlMinaeeiPiis limestone series. ( »n a small creek a few miles lielow
Coal Creek, a short distai'ee up. the same coal is found. It is i)rob-
nlile, tiierefore. liial at this point the upper confil cratie ( Koeene)
beds conu' in, overlyin;; the rocks expo.sed at the mouth of Fortymilo
Creek: and this seems to furnish strati,i;raphicai evidence for tlie cor-
relation of these latter nx'ks with those at the mouth of .Mission
Ci'cek. The fornuil ions exposed alon.ir the \'ukon. in the vicinity of
Fortymile Crt'ck. .Mission Creek, and Kandik Ifiver, therefore, seem
to form a continuous belt infoldecl with the overlying: conjilomerato
series an<l the underlyinjr 'I'ahkandit series, so that the river cutlinj?
across the folds exposes ail llu'se dilferenl series, toy:ether with tlio
older rocks, in alternatinj,' Ixdt.s.
'J'lie Napoleon Creek aii<l Chicken Creek occurrences ai'c separated
from the other localilii's, but these rocks lia\'e close litliolo}j;ieal and
structural reseniblai to the others, and like the rocks on Aiiieriean
Cr(>ek, are characterized by ,. la.sal con!j;lomerate whicii rests uneou-
fornuibly upon the l{ampart and Foi'lymile series. All tlu'se rocks
nuiy thou be prcvisionally ci)ri'elated as ii sintflo series, which may b.'
called the .Mission Creek series. The upper limit of this series may
be repirded as the heavy beds of conjj;loinerate, .sandstone, yrit, and
shale, which carry abundant ])lant remains and beils of pure li.i;nili(!
coal, with brilliant luster and conchoidal fracture and freiiuent grains
of amber. The lower limit of the .series is not so clear, but is approxi-
mately the heavier and purer limestones, with some eou}i;lonierales
and shales. In some of tlies(> limestones Carboniferous fossils are
found.
The lithological antl structural resemblance between some rocks
which have been classified as j)ai't of the Tahkaudit .series and some
wliicli have been put into the .Mission Creek series is v(!ry strong?.
For example, the I'oeks lu'ar the nH)utli of Fortymile Creek strongly
resemble lithologically and sti'ucturally the rocks below Mynook
Creek, which carry plant remains suggesting Devonian age. Possibly
further evidence may show that some of llie.se rocks should be ])ut
into divisions different fi'om those whi(di are now considered best;
the jjoint aimed at is simply to make a provisional classidcution.
AOK OK THE .^IISSIOX CKKKK SERIES.
In the Alission Creek series no fossils were fouml by the United
States (Geological Survey party except indelerminable plant remains.
Mr. K. G. .McConnell,' of the Canadian Geological Survey, disi'overcd
below the mouth of the Tatonduc liiver, in the shales uiulerlying the
heavy conglomerates, specimens of Aucella mosquensis var. voncen-
' Auii. Rept. Oeol. Nat. Hist. Survey C'niiailn. IsnHjtli, V<pI. IV, pp. L'lD, l;t8U.
Bpniii.l
THE MISSION IRKKK SKIUKS.
1S3
//•/(■'(. Coiiccriiin;; iIk' stratijirnpliical si^'iiilicaiii'i' of llicsc fossils,
Mr. 'I'. W. Sliiiilon, of tlif I'nitcd States (iooloj^ical Survey, lias kindly
supplied the writer with the foUowiii};; note:
Tlio guiins Aiiccllii is with very few doubttul oxeeptiniK cciiitinifl t.i tin' I'lppcr
Junissic and the Lower Cretaceous. Tlio foniH that Wliiti'avis calliMl Aiurllii
miisiiKfimin viu'. ri)iictiilricii certainly do not have a ,i;reati'r raii^e tliaii that, and
they are vrobahly Lower Cretaceoun. (See Bull. I". S. (Jeol. Survev, No. l:l;i. pp.
40-1 r.)
DKFIXITIO.S' OF THK AIISSIO.N ( HKI'.K SlOKIKS.
The ."Mission Creek series may then he descrihed as a siieccssiou ol'
caleareotis ami earholiaeeous shales with tliin-hedded limestones,
sandstones, and eon^donierates, of eonsiileralil(> l)ut not enorinous
tliiekness. 'I'his series often rests tineonformahly upon the Kanipart
scries and older rocks. It is norniiilly underlain by the Tahkandit.
series, the odfies of which it overlaps and from which it is iiroliahly
S(>pai'ated by a sli;,dit dciirrce of uiiconfoi iiiity. .McConnell ' notes on
the I'orcupine Hiver, below the mouth of Driftwood Kiver, the expo-
sur(> of a contjict between sandstones and (luart/.itcs with underlyiiii,'
coni])aet bluish limestone. The sandstone iiiid quai'tzites jire overlain
by soft bluish shales with harder ealcareoi;s layers, and are sii|)-
posed byA[r. ."Mcl'oniicll to be Cretaceous. The(>oiMpact bluish lime-
stones are lillcd in i)laccs with broken criiioid stems ami other fossils,
and iiro referred to the I'aleozoie. The contact between the lime-
stone and the overlyinjj; rocks hits the appts'iraiice id" beini; sli^rlitly
discordant.
The .Mission Crook series is directly overlain by conj^lonieraii<- beds
Ciirryinji; abundant i)lant remains which indicate Kocene aj;e. The
siKblen abumlance of these coimlomeratcs ^ivcs some reason I'or
susix'ctiiifi; a slij;ht unconformity, but it certainly is not ureal.
Tl
10 oeciirroiice o
f th
icniis Alice
ill the .Missi(jn Crt
scries
shows that it is, in part at least, low(>r Crolaoooiis, although otl
re (doselv related to ti
periods maybe re])resciited. 'I'he series is more closely related to tlio
Tabkaiidit series than to any other, ami the litholouncal and paleonto-
loflical boundaries between the two arc not well determined. They
may be colleotiyely considered, however, as a grand series of setli-
ments raiij;iii}j: i.ii a^e i)rol)ably from Devonian to Cretaceous, and of
this the Tahkan<lit series forms tin: lower and the Mission Creek series
the upper di\ision.
C()KKKSl'().\lJlX(i STHAT.V IN" OIHKl! l.( K ALITIK.S.
Mr. H. G. .McConiu'U-' notes at various points on the I'orciipiiK*
River bluish shales with sandstones jind eoiijflomi'iates, wliich carry at
different points AitciVn iii<is(jii( iiKl.y var. '■om-inlricd and Inocenimiis.
At the ends of the Lower Kaniparts on the I'orcupine. Just above tho
> Op. cit., p. ia«D.
'Op. oit.. 11. li-.D, i-':d.
\H\ (;i;<)I,()liV OF TlIK YUKON (iol.n DIsTRKP. ALASKA.
l.c-imiinvnlllM' Fliils, n.cks liiivin- lli.->.'si lii liol.i-ical iVjiliiros
.M.^iir, l.iil Irnm tliciii ii,. I'os.sils wm IliTinl. 'Ilicy (.Vfplit' licro
li-uciiilii'i'lii^' liiiioidiics wliicli i-.ii'i'v .I//-///'" ri I iriiliiri.s nnd
Vcllcpw l>
I'liliriMClllMI \ >|)r('ilM('tlN 111' .Mll'ltls, alH
1 Wl
iii'li an- <M>iis
iilcrcil hv "Slv,
.■M.'Coiin.'ll as ivlVrahl.', in part al Ica-l. i" Hi" I ).>\(>riiaii. Tlit'so
ivnlvinj: nicksarc rcpr. x-iili'ii on the map of llif \iilvnii iX'M dislrict
as l)('l()iiu;in}j: In tin-
y\
issimi ('i'(c
u liilc llir iiii(lcrl\iiii;' liiiu'-
sliiiics all' inappi'il as pai'
I'ldspcrlnl'S wllii
I (if llii' 'ralilNainiil scrir
III llic lii;
ri'iici' (if cdal (111
t 111' .Missidii ( 'ri'c
lia\i' passc(l upllic Kaiidik lii\« r.ainl tliciicfacniss
r.lack liivcr and diiwii idllit' i'lii'cnpiiic, icpoi'l tlicociMir-
llic l!i;r I'.kudv Uivcr. U is pn.lialdc, tlicrcforc, iliat
rics (ir ihc ovcriyiiiir Ki'iiai sci-ics. or liolli, aro
• \|)oscd. 'riic l(icalii.\ (if llii'st (•iii-rciiccs. houcxcr, can not
llii'i'i
be asci'ilaiiifd from llii' |irospccloi>
l)i<
irmalions as diMwii aloii
ilid llicrcforc llic Imiliidarii'S of
i; till- lily r.lack Ki\ cr on I lie map aro
liy])oili('' 'al.
.Mr. \V. Oyilvic' slates that aloin; tlic Tatondii liivcr for J7 iiiile.s
iiliovo its monlli all" dark shales ovi'ilain liy rnu'-jiraiiifil coii^rlonicr-
atcs, llicsf beds hciiifi similar to lliiisc ohscrxcd on llic Yukon. At
t wo piiinls
this distance limestones rise to the siirfaci from lieiieatli
1 lie shales. In the upper jiart of the \alle.\<if the Tat olid lie tile shales
and coiiulomerates an.' replaced li\' ;irayis|i I'aleo/.oie limestones.
Similar limestones occur on the walcrslieil scparal iii.n' the 'raioiidu
from the l'oi'<'iipiiie, and here form a raii'^c of liiiili molinlaiiis; they
jil.s iirdowii the rorciipiiie as far as I he Cilhedral rocks, where
th
ev are :\iiiiin overlain ii
V dark shal.
THE KENAI SERIES.
l•l!l•;l.l^Il^•Al:^■ sr '.■ik.mi;nt.
The name K'eiiai is iziveii by I )r. W. 1 1. I )all to a I hick series of fresh-
water b<'ds carrying' abiiiidant plant remains and frciiiiciit seams of
liunit ic coal, which is often llecked with amber or amber-like resin.
T
le liailie IS del
i\('d from the Keiiai Peninsula, on Cook Inlet, where
these beds are well exhibited. l''or the full description of the series
and bu the details of the dilVereiit occurrciiees, Dr. DalTs work
should be colisillled.-' Tlie deteriilinat ion of the a,i;t' of these beds
<lepeii(|s n[ion the di'terminat ion of the ajrc of the fossil Mora, which
as formerly reuardi'<l as .Mii lie. bid is now considered t
o lielouu:
t:> the Mocene. In the followinii' payes are described certain rocks
which ajipear to belonj; to this series. 'I'liese are all in localities
examined by the I'liited States (Jcolouical Siirvt'y parly aloin; the
Yukon ]{iver in the suinmci' of bs'.iil,
i.\m Hc|jt.(ii.'iil Xiit Ili»t.Sii)'V('> (■iiiiu(la.l.'i-v'< si'. V.il.IV.ii. risD,
•Bull. U.S. Uuul. survey Xo.fl. t'orri'limuu Papirs. Xl'oi'ciu'. |).;.':U.
TIIK ::KN.\I Sl'.UIKS.
IS;-)
DlSTHIIifTloN \NI> (iKNKIiAl. |iK,S( l;l I'lK iS.
Jtihiir .]/l:^.siiiii Criil;. — Ahniil 7 iir > iiiilc^ ln-lov .MJN.siun (ircU. mi
the \'uUiPii, llic tliiii ii'ildcd liiiii'sldiics. siiiiilslniifs, ami citilMiiin \is
•shak's (if Ilic .Missidii (I'l'ck sci'ics aif Miccci'ilcd hy ii\cil\ iiii; iiias>i\i'
eoiiKloiiicratcs. Tlic |i('hl)lcs in ilicsc ciiimliiiiiciali"- aic Miiall,
anil arc iiioslly luadc iq) of (litlVrciil xaiictics of t[\\,\' .mil dicri or
,jas])('ri)i<l — Jli'ay, white, Mack, ami especially pale-^', TlieNc
rocks ])ass into samlstoncs ami cDai'sc ^rrils, almosl iii\ aiialily L;reeii
in color, ami lliese iaio samly ari;illaceoiis liim'sloiie- and c-ailmiia-
ceous shales \vlii<di eoiilaiii l're(|iieMl seams of iii| ii'c. Ii_ 'il ic coal.
This coli^;loiiicial ic series is infolded wilh Ihc iiadeilyin^ .Mission
Cieel, M'ries. ami the ^■nkon culliiiii' across these folils exposes the
two in allenial inn' lii'lis nearly lo the 'I'ahkamlil Ki'.er. wheic the
])nre-white linieslones of the 'I'alikanilil series, ^nww of which cai'ry
Upper Carl) nil'erous I'ossils. come in lieneaih llie .Mission Ci'eck
series.
In the eonnlonii'ral ic series overlyinu' the Mission ( reel^ series llie
samlsloiies and shales very ucnerally eimlain ;il>nnd;ini le.il' iinpies-
sions, and ahoiii J,") miles below 'lissir)n ( fi^'k a colleei ion of these
fossils was made, from which the lollowinji' species were i<lentilied by
1)1-. I'. 11. Know Iton : .
SiMiuniii liiiiLTsilortii.
KicusV iiliisk:niir.' Xewb.
C'liryhis miii-i|ii:irrii ■ i Torlies) ITcer.
Ptero^jicrniitcH (li'htiittis lU'c;-.
'rhese fossils ai'c considere(l liy !)r. Knowiion to lichum to the
Eocene. .Vt the Sana' plai'C where they were collected a pelihle
of line, dense. f,'ray, calcai'eoiis sandstone, like the yi-ay sandstones
of the nndcrlyinu' Mission Ci-i'ck series, was loiind in the coninlom-
erale, su.u'u'csli'iii' s(ane sli^ulil um-onfornuty, or at least an erosion
interval, lietween the t wo series. The iii)per plant-heariny: sci'ics is
very llii<d<, and alllion^rh no actual measurement was undertaken. I he
ini|ii'cssion liixcn is th.at it is several tinn's as thick as the nndcrlyinu'
^Mission ('rc(d< series. .V ronuh estimate in the Held made the ihick-
in'ss of I he upper series a lion t In, nun feet, and that of the .M issimi ( 're(d<
scries about l,n(i;i feet. This est iniale, however, was based on no data
whatsoever, but simply expressed the impression iiaini'd after seeing
llie continuous and numerous i-ock exposures foi- many miles alonu
the river. Itoth the U|)per and the lowci' series ha\e been folded at
the sanu' tinu' and iii api)roxiniatcly the saifie deuiec. 'i"he st resses
appear to have been local, foi' in one exposure the strata are hori-
zontal and in the nexf vertical or xiolently contorted. No xcins
worthy of nu'Ution wiu'e seen in these rocks and no <likes were act uall.\'
()bser\('(l. although certain objects seen at a distance were suspected
to be dikes.
\\
•fj;
T^W
186 GEOr.OGY OF THi: Yl'KdX GOLD DISTRICT, ALASKA.
Ahni-i KmiiJik Riri r. — Scvoral niilos iiln)Vi' llio Kaiiilik Kivci' ot'our
njiaiii .iTfocn },'rits. saiiilstoncx. and ronirlmrn'rati's witli bbu-k shales
ooiilaiiiiiii; coaly scaiiis. All tlicsi' rocks contain l)a(lly pi'os(>rvt'd
Iilant i-ciiiains. I.illioiofjically iliosc beds an' exactly like those in
the locality just described below .Mission (reek. As in the last-named
locality-, the jiebbles in the conij:lomcrate consist mostly of silica in its
various I'oiMns, but a siu'cimcnof ilai'k ;ri'cenisli-;;iay ,^rit is seen under
the miei'oscope to be 7nade ui) of irre,i,'ulai- and often sharply anij;uhir
fra^Miientsdf feldspar and iiuartz Tlie fi'ldsi)ar, which is plajfioclase,
is the pi'edominalini: material, ami occurs in bi'oken, lath-shajjed erys-
stals. The Lfraiiis of quart/, are not much ronmlcd, and there is some
orthoelase, aniiile. lioi'ublende, anil mica, with line calcareous and
kaolinic material. The naluic of this ffvii shows that it has been
derived from some basic ii;:iieous I'ock, probably a diabase or diorite,
and the diabases of the Uampart sei'i(>s may be susju'cted of haviuij
fui'nislie(l the material. The richness of the rock in hiirhly |ierishable
minerals, moreover, and the anjrularity of the irrains show that the
material has not traveled very far from its oriirinal source.
On the river al)o^'(> ami below th(> locality just mentioned come the
undcrlyini;' darker, ihin-bcdded limestones and shales of the .Mission
Creek series.
Cmil Cfdk. — On tloal Ci'cek. which enters tlie Yukon a few miles
belo 1 ihe nKMilh of Fortymile (reek an<l on the o|)p()site side, coal
occurs some '. .' or more mil(>s above the mouth, as .Mr. ( ><;il\ ie. of the
Canadian (ieoloi^ical Sur\ey. has informecl the writer. One specimen
given by Mr. Oi::ilvie was a pure, hard, black liirniti lal with bril-
liant luster ami perfect eoncholdal fracture, ancl contained t iny tleeks
of ])yrite and larjrer' uraius of amber or amber-like icsiii. This coal
is like that found so frecplently in the rocks of the Kenai series, and
it is probable, Iherefore, that these rocks cross Coal Creek some miles
above its mouth.
On a small cie<>k a few miles below Coal Creek, on the sanu' side of
the Yukon, coal is also t'ound, identical in appearance with that on
C()al Creek.
The e.xisteiiee of line-;rraiiu'd conglomerates overlyinj; dark shales
nloufjthe Taton<luc for iT miles above its mouth has already l)ceii
referred to under the li.'ad of the Tahkandit series. These beds are
considered by Mr. 0,irilvie lobe the equivalent of beds observed cm
the Yukon. In the upper part of the \ alley of the Tatondue they are
replaced by i;rayish I'alco/oic limestoiu's.
Ahitrc^fij)iiiiikCriilf.—\Un\\ J.'i miles abr)Ve Mynook Creek the
green diabases and tulTsof the Kampart series ai \erlain uneoii-
formably by conglomerates and grits, with some limestones and
shales, all thin-bedded. The grits are green in color, owing to their
derivation from the underlying rocks of the Hami)art series: (he
iualri.\ of the eougloinerales is also green, and the pebl)les are made
sprim.]
TlUC KEXM SEHIKS.
187
up of varicolored choi't (tr .iiis|HM'oi(l. and alsoof diabase and diahasic
tulTs from liic iiiidcrlyiiifj: roctcs. 'rii(> liiiicstonc is in tliin layers,
gray or jjfreoiiish in color, very fmo-Kraiin'd, and wiih a sniooili mn-
C'hoidal fraetiUH". In tlic slialo arc froiiucnt scams of I'alhcr impuro
lignitic coal; llircc distinct scams arc c\p<iscd on a clilV here just
below tlic moutli of Wliymjx'r Hivcr, or. as il is ordinarily caileil liy
Alaskans, IIcss (,'reeic. Along one of these seams a I uriuel has been
driven by Oliver Miller, the discovererof gold nn Miller ('reei<. in tlie
Fortynulc district. The coiil, when ])urc, is of brilliant luster and
ooiK'hoidal fracture, like that on Coal ("reek, and is lignitic. The
thickest seam of i)ni'c coal uote(l was 18 iuciies thick, and theie are
many thinner seams alternating with impure bauds, or "bone," ami
with clay ])artings. The pure coal c<iutains ambci-. like the coal of
Coal Ci'cek and vicinity. The l)eds at this point are nearly vertical,
and arc even locally overt ui'ued; the general strike is \. i;.V !•;. i'lant
remains arc everywhere, and some were collected and h.ive been
id(Mitilied by l)i'. V. H. Knowltou. These will l)e rcfcri'cd to later.
^Vbout 15 miles bidow this locality the sanH> scries has a strike due
north anil a ilip 45" W., and ali<iut ."i miles fartlier below, the contact
of coaise green diabase belonging to the iiampai't series wit li the over-
lying basal conglonu-rate of these plaul-beariug rocks is show u. The
pebbles in this congloinerale are not usually more liuin 2 or ;! inches
in dianu'ter, and consist xcry largely of the dilTerent varieties of si 'lea;
some, however, are coarse diabases and tufl's, like tliose of the Ram-
part series. Abo\e tiu' lowest bed the conglomerate Ik mes liner-
grained ami alternates with thin-beddeil grils and black carbonaceous
shales. The shales contain in<listinct ])laut remains.
-VI th<> month of Myuook Creek are ex|)osed conglomeralcs, gri.s,
and shales similar to those just ilescribed. The beds arc f.iirly well
con.solidaled, aitliouiih some layers are lnose and iucoliei-ent. The
coiiglonu'rates are generally line-gi-aiuc<l, ancl often contain nodules
of limonite and silica; the shales carry snudl scams anti fragments of
lignitic coal, which often contain si)ecks of amber. The pi'bbles in
the conglomerate are [lartly derived fi-om the diabases and lutVsof
the liami)art series. At the mouth of the ereeU the beds strike X.
80" E. and dip <!() N\V. Above this point a continuous section is
exposed along the bank of the ^■uk(lu for nearly i' miles. In all this
distance the strikes remain the same, wiiile the diji is steadfastly to
tht north, so that continuously higher and higher beds are exposcil
as the distance from the mouth of the creek increases. Toward the
end of I he section, however, the dip becomes grailually shallower,
and at last is in places as small as iV) . The thickness of these nni-
forndy dijjping beds must b(> very great, unless there e.xist faults
which were not noted, and which may jiossi'bly operate to increase!
the apparent thickness. The uppermost beds exposed have a char-
acter and a composition substantially like those of tlic lowest bcils,
^1
18H (JEOLcMiY OF THK VIKON GOLD DISI'KICT, ALASKA.
l)Ul I
M'i'c IS a III
iirkcil ililTtTcii
lli(' dciri'i'*' <>r CDiiso
iidati
coiiciciicy.
tain sdiiictiiiH's Idosc la\
C'liiiiildiiicrali's, irrils. JHmI
"lie lowest beds near the iii(iulli(ir .Myiiook ('rci'k coii-
is, yd arc ordinarily (irmly consolidated
^liali's. Ill llic liiirlicr liori/.ons, liowever.
Ins consolidation liccoiiics \ei'\' yrai
iiaily less, until the ni)i)enni)st
bcilsareol' little coliereiil clays and shales with loose sand and uivivels.
^Mlhonjfh these ui'a\('ls eori'espond in c(nn|iosit ion to tin niilonicr-
ates in the lower beds, they are so little iiidnrateil Ihat the pebbles
can be easily and cleanly pickc<l oiil ol' tlic> mat rix ami the whole rock
can be remo\ed with a slio\cl. The jfei'eial ■>
l)e(ls. therel'ore. is decidedly dilVerelit from that of the lower ones,
and if ihe two localil ics were not connected by a <'on1innouse.\i)osnre,
the san<ls and uravcls would iindonbledly be considered as beloii^inji'
to a decideilly yonnycr series than Ihe conji'lomei'ates.
'riiroujrhoiil this series, from to]) to bottom, are fi'e(|ueiit. seams of
li.ii'iiilc and li.unilic coal which contains specks of ai
ppearance of die iip|>ei'
'h
.al
seams arc u-ciierally oxcrlaiii and underlain by sandy cla\'. and arc
associ;iled wilh earlionaceons shales <Min1ainiiiy plant remains, stems,
find ofleii lai'irc frai;iiii'nts of trees. The best leal impressions were
found in the upper, less consolidaled jiarl ol' Ihe series, and theseare
regarded bv Dr. KiiowInjii as V,
Thespecies identilicd are als
round al .MillerV coal mine. 'I'lic correspondence of the lowest part
of the series, with the beds at Miller's coal mine, is bevoiid a doubt.
find tlier«>forc I he whole series <
arsto beloii"- to 1 1
le r.ocene
Slil
the loose, iiicoliereiit nature of the ii|i|icr strata, comparecl with the
coiiiiiact. well-consolidated condil ion of t he Kocciie in other localil ics,
g'ives rise to the doubt as to wlicl her all should 1 lassilied under
exactly the same head, and whellu'i'the iincoiisolidated bods may not
beloiii;- to a somewhat more recent ])eriod.
I /"in ///( 'I'll III 1 1
.V boll I :;.") miles abos'c the mouth of the Ta
nana.
on the \'ukon.coiiie in coarse <'oni;lonieratcs, yreen jirils, and mica-
ceous shales only part ly consolidated. The Liriis and the liner mate-
rial of the coiiiilomerales are e\ ideiit ly made up chielly of detritus
from thediabasic rocks of the Kamparl series, while the pidibles in
the coimioinerate are laryidy of the \arieolorcd chert or Jasperoid,
which occurs so abundant h in the same ro<'k
Thei
e are also occn-
inal pebbles of white eryslalliiie quartz which may be derived fi
the X'eins of the Kirch Ci k or l''or(yinile series: and in
coarse urits there is much line uranit ic del rit us. Tlii
some of tin
s conulonierate
overlies the Kamparl rocks, which arc exposed fart her up the river,
and for some distance below the contact has a li-eiieral soiithwesl dip,
which it chan.u'cs farllu'r down for a northeast one. The strike is
usually noriM or northwest, so Ihat the whole belt seems to have a
jicneral .synclinal structure. I''art her down the river llieso eoiiKhun-
eiates arc succeeded by ohler rocks, consist inn' in part of niica<'eous
and calcareous i|iiart/.ile-scliist wiih<piartz veins. These scdii.stsliavo
been referred to the l'"orl \iiiile series.
p'
i
Hill
H '
SPriiR.]
THK KEN A I SKRIES.
1«9
Xoai'ly opivjsilo tlio iiioiilli ol' lln' 'raiiaiiii liivcr, alioul :! iiiiU's
above the tradiiij; post known as Tanaiia. aic airain lonnd (mtcicips
of foarst' oonjiloinoratcs similar to liiosi' last (ifscribcd l)nt scpaiatccl
from tlicni by tlic belt of oldcf rocks. A\ this point 1 In Mirlonicialcs
lie nearly horizontal ami ar(> inlcrsi ratilic<l witli laycisi'f iticrn i;rit
wliii'li contain jdant I'cmains. 'i'lic pcdiblcs ai'e lai'uc, boinf,' often '> oi'
Ci iindies in diameter, and are commoidy siibaniridai' in shape. One
liowlder of (piai'tz noted was over a foot in diameter. (Jreeii dialiase
and otlier cliai'aeteristie foeks of the Hamjiai't sei'ies make np a lai'y;(^
propoftion of tile ])ebbles and bo\> Iders. 'i'he micai'eousipiarl /.-schists
of tlie ISii'ch ('i'e(d< or l'"ortymile series also make uj) a \ery lar^te
part, and tliere are qnai'tz and chi'rl or jasjieroid of all \arieties and
of all colors, (iranite pebbles, however, conid not lie found in this
localitv. I'l. XXXIII is a i)holoj;raph of a mass of this con,L;l<iiiicrato
newly fallen from the fai f a <'lilV.
ndiiir flu Milozlh-iikdl. — .\ few miles below the .Melo/.ikakat (seo
]*l. XXXIN') the ;iray limestom's and indnrated shales which have
already be<'n describetl under the head of the Tahkandii seiies are
overlain by coiijiloinerates, ^^reen ii'rits, and shales contaitnny plant
I'emains. The pebbles in the conjrionierate are mainly of iliahasi' ami
diabasic tnlfs from the liami>arl series, of mica( lis schist fiom the
liii'ch ('re(di or I'"ortyniile series, and of coarse fii'anile like thai of
the great intrusive ma.sses obserx'eil in the Lower Kamparlsof the
Yukon; there are also frajinicnls of line-irraine<l, greenish limestone,
like the limestones ' f the 'I'ahkaiiilit series, e.xposccl inimeiliately
above. ^Vboiit li miles liidow the Melozikakat these c<ii|Ml(iiii,.i'jites
strike N. 7<l K. and dip :.'ti SK. ; about H miles farther down the
river the same rocks strike N. lio W. and dij) ;!■"> SW., and the fold-
ing al this latter jjoiiit is more marked. In both these localities the
conglomerates are X'ery coarse, the pebbles being as much as il or H
inclies in diainetei', especially tho.se of granite. About 7 miles below
the last-named locality were found sainlstones and soft iday-sliales,
both being i)lant remains. The sandstones aregreeiush in bands, like
those above described, but ,, mostly gray and of pure nposilion,
jcing made up eh lolly of ((iiart/, grains, while the mdi nary green sainl-
stone is largely composed of feldspar. These rocks strike \. ijo K.
and dip 35° XW., and are continuously exposed, with a uniform di]),
for 5 or (I miles along the river, thus albu'dilig a line cross-section.
The thickness of strata exposed in this section is apparently very
great, but it is probable that this appeariince is largely due to fault-
ing, as noteilby I'rof. I. ('. Unssell.' Of this Professor Russell speaks
as follows:
The finest eXHiuiile of nionoclinnl structure seen in nacpmliiis,' the Yukon. thou},'U
on ii coniparatively small hi'ale. was in cliffs of sauilstono anil slate l«)Vilfring the
right hank of the river tor sevrnil niilcs, at a lofahty some I.") or L'll luilcs lielow
'Note8ontllesurtlu■l^^,"M■l(.^;.v.>l ,\liiskii: M-.U. Uim>1, Sue. AiiuTii-a. Vul. I. p. liw
:5,
,t >-
,1
190 GKOr.OGY OI- THE YUKON GOLD DISTUICT, ALASKA.
the moutli of the Mi'lozikaknt, or iniilwiiy bptweon Xnlato and Nnwikakat.
Thfsc Bamlstoncs contain the leaves of diriduonn trees, and belong to tlie same
systiin as tlic roiks at \iilato. which have been described by Dall.'
The river bank at the loiality referred to is extremely preciiiitous, and exiioses
a fine section of tlio rocks, wliich dip. in general, northwest 2.")° to W)', excejit
where disturbed l)y fanlts. Tlie disi)iiiceinents trend near'.y north and south, and
appear in the clitTs as in a diagram. In the best-exposed portion of the section
there are six or eight important fa\ilts within a sjjaceof about S mih's. These are
parallel, and liead to the east at an angle ranging from )i'i to4()\ In each instance
the strata are distnrliecl on ;i|)proaching the breaks, but soon return to tlieir nor-
mal dip. At each fa\ilt a lateral valley has been excavated, the westsiile of which
is a smooth, even rock sIojh', frequently slickensided, and is in reality the heaved
side of the fault. The east wall of each of the valleys is rugged and broken, and
the strata in the iirojecting ledges usually show a high dip .oward the east. In
other ravines, where the structure was not clearly visible, the peculiar topograjjhic
conditions imlicated a similar origin. These faults are iiLstrnctive Un- the reason
that they illustrate the manner in which a series of displaced blocks sometimes
jiresent a nearly uniform <lip. so as to appear as a .single monocline when the
exposures are not sufficient to sliow the true structure.
riaiits (•((llcctcd from tlicsc beds have lit'cii i)f(ivisi(mally referred
l)y Dr. F. II. Kiiowlton to the Koeeiie.
About li miles fartlier down tlie river were iiote(l 11i(> same s>'<^"'"-
isli siiiidsloiies aii<l soft sliales, earryiiii; leaves, stems, and small
eluinks of hard, black liirnite. In these beds, niin<,'leil with tli(> i)laMt
remains, were found fre.sh-watcr shells, which, however, are not eliar-
aeteristie iMioujrii to determine the horizon. At this point the be Is
strike \. 7(i" K. ami dip 40' \W.
^\t a point some H or 7 miles beyond that last mentioned weree.xandncMl
bliiisii-jiray and brown sandstones, jrrits, and eonj^h)inorates, difyeriii}?
considerably in appearance and color from tlio rocks in tlio localities
further U]) the river. These beds are considerably foldcfl, and even
slifjhtly overturne<l. There is a stronji .jointinjr. trendinfj; due north
and varyiny: in di]) from vertical to lib" E. Alonj; these .joints and
other fracture ])lanes are slickeiisidinf? and slight faulting, and there
are snniU stringer veins of calcite, often cutting across the slrati-
fication at right aiigl(>s. The conglomerate contains jx'bblcs of schist
like that of the IJircli t'reek series; of diabases, tiilTs, and chert from
the Rampart series, and also of : haly green liniestoin' in large pebbles,
the derivation of which is uncertain. The general .strike here is
X. 0()° K., while the dip varies from :!0" N\V. to vertical, or is csveri
locally reversed. About or 7 miles fiirther down come bluish-gray
sandstones and sandy shales, striking N. 7o° E. and dip])ing r)0° SFL
Tliese (iontain many plant remaiiis similar to those collected in the
other exposures between here and the month of the Melozikakat, and
the sandstones are rii)ple-nuirked.
A few nules below this last exposure come in high bhiffs of horizon-
tally bedded silt which conceals the other formations. Tliis silt is
>Aiii. .Toiir. Sci., L'd serii's. . il. XI^V, l.-sfts, pp. 117-118.
iii
!i
if-^
i
:i ii
rf4
, .1
i
m
BPDBR.]
THK KENAI SEIilES.
191
the only deposit exposed alonj? 1 lu; ])anks for about ;t5 miles, ami it
apparently extemls away fr>iii tlie I'ivei' mi liolii sides for a iimulier
of miles, for the country is eonip(jsed of broad, level Hats, wiiieli foim
a marked contrast to the rougher topojtraplix' alrnxf and below, and
which stretch away to the distant hills. It seems pi'obable tliat tliis
silt was deposited in the bottom of a lake wliieii ()<'eu])ie(l the rejiion
of the flats and whieh was drained in cinnpai'atively recent time. At
the end of the Hals are two eminences, whicii are called the 'I'win
Jlountains; they are close toy;ether, on tlie left-hand side of the river.
Nearly opposite these mountains, on thi^ riijht-hand side of the river,
is a steep rock clifT, about :!(Mi feet hijrli, comiiosed uf c(imi)aet, blue-
gray slialy limestones and sandstones. These rocks reseMd)le, litho-
logically, those seen farther up the I'iver, and contain indistinct plant
renuiins, buti they also contain marine fossils, which Dr. Dall considers
to be probably of Jliocems afj;e. .\n estimated thickness of al)out <iiM)
or 700 feet of strat.a is exposed in this clitf, and the beds are well
folded. Tlie general strike is N. 80° W. and the most important dip
30° SW.
Bfhrcen the Koijukuk itnd llic scu.—Xt the mouth of the Koynkuk
is a sheer cliirof magnificent height rising directly from the river ,iiid
known as Koyukiik Mountain. This rock is of basalt, and shows on
its naked face very beautifully and regularly two dilTerent sets of
joints, due to contraction in cooling. The l)asalt has burst through
conglomerates and sandstones, whieh it indo.scs in hirge masses. A
short distance below the mountain the sedinu'iitary rocks are exposed
in a (Munparatively un<listurbeil condition. They consist of black
shales with beds of brown-weathering sandstone, and extend from here
at least as far as oO miles below Xulato; according to Dr. Dall, as far
as Kaltag. These rocks are referred by Dall to tlie marine ."Miocene.
At the Holy Cross ]\[ission dark-blue sandstones and conglomerates
■were noted, and at a village l^i miles above Andi'eafski are impure
sandstones. All these rocks are well folded, although not intensely,
and are mingled with intrusions of basaltic nat are. ]?elow Anil reaf ski
no outcrops were noted as far as the mouth of the Yukon. tSt. .Michael
Island is purely volcanic, being made up of basaltic lava and ash.
The Koijiikuk Bircr. — Concerning the rock formations along the
Koyukuk, Lieut. II. T. Allen ' notes that "the geological formation of
the country drained by this liver is in appearance very similar to
that of the Yukon from Yakutskalitnik uft, so that what may be
written in respect to the geology of the Yukon will in a large measure
apply to it." Ho also notes that " on tlie noi-thern bank of the Koyu-
kuk are indicat ions of coal beds. " According to t his report, those por-
tions of the Koyukuk which have been explored probably flow mostly
through Tertiary strata, like those which have .just been described.
A few j'ears ago considerable prospecting was done on the Koyukuk
i,]
> Beport of an Expedition to the Copper, Tannna, and Koyukuk rivew, Senate Doc., ISO", p. ISO,
1 "'
m
;*. I
11)2 (IKOI.OfiY OF TIIH YUKON COM) DISTIUct, ALASKA.
jiinl some irnlil was tiikcii "ill. A posl was cslaMislHMl ini this rhci'at
Aiclic Cil \ , iioi'l liwcsl llMl mill's or so Iroiii 'I'aiiaiia station, on tlio
^'ukoii. lint lias lately liccii aliMiKliiiicil. A< I'lllrifj to tlic ri'ixirts ol'
in'ospcctoisaiiij tiadrrs t he ;.'ol(i is cDiitaiiii'd in IhmIs of cnn.irlonici'alt'.
(■()l!l!i:l..\ll().\ AM) A(il:.
Tlio coii'iloini'i'alif series exposeil below .Mission Creek and lliat
I'oiinfl above the Kanclik ii'ivcr evidently ai'e the same, since tliey ai'O
identical lit holoirically and st ijitii;r'aplMcally, contain the same phiidi
lemains. and ha\t' the sam<- amonnt of imliiiation and l'oldiii<j;. The
strata above .Mv nook (reek, at .Miller's coal nunc, liavi' the same <diar-
actersas in the two localities last mentioned, cori-espondinj; (dosidv
ill nal lire and composition of the beds, in t he deM-rei. nf eonsolidat ion,
and in the li;riiite seams and plant remains. Immediately above the
month ot' .Mviiook ('re(>k the lowei' bed.s in the section exposed havo
the same character as those a! .Millei"s coal mine, but are less consol-
idated. Toward the top of the thick scries e.\]iosed aloiiir the banks
of the \'iikon at this point the beds bccimic proj^rcssividy less con.sol-
i<lated, until linally they are only aravels, sands, and slijrhlly iiidii-
rated clays; yet t liese upper beils are conformable with tlie more con-
solidated ones below, and contain liirnilc seams and jilant remains
similar to those found in other localities. l''roni these loo.scdy coiisol-
iilate(l beds specimens wore collectC(l which were idenlilied as Fii-ns'/
(ilii,sk(in(i/ Xewb.. and Cori/liiN iiKii-ifiinrrii (Forbes) Ileer. From the
beds at .Miller's coal mine were identified —
PliraKn.ito.s iila-ikiiiia';' Hecr.
FicnsV iilasliiiiiii'.' Xmvli.
Coryliisniaciniarrii iForbi's) Hpor.
yu'Tcns? sp.
Pi>]mliis liulsamoides Hecr.
Platami.s sp.
Vitis creiiata? Hecr.
Carpitcs s]).;
and from the locality below .A.ission Creek —
Seiinoia langsilovfii.
Ficns? alasttaiiay Xcwli.
C'orylns iiiac(inarrii'.- (Forbes) Hecr.
Ptprosi)('riiiite.>< (Iciitatii.s Hecr.
Since these three localities have at least two species in comnion. Dr.
Knowlton considers them as approximately e(|uivalenl in ]ioint of ajro,
and the combined collections from the three localities j>ive 7 .species
which are characteristic of a liorizon formerly known as the "Arctii;"
."Miocene, but wiiicli is now considered to belonji: to the I'pper Koceiio.'
The beds broufjht lofretlicr in this correlation are closely alike lith-
olofrically, with the exception of the upper beds of tlie series exposed
■ Sen Di-. Kii.iwll. Ill's report, pag,. 1!« ; nlsu A review (if tlie fossil flora of Alaska with ilesei^-
tiou of new species, by F. II. Knowlton: Proe. T. S Xat. Mus.. Vol. XVII. pp. ■Ji\:,-JH).
' It
M
■ : ' I i
TIIK KENAI SEIUKJ*.
Ift3
iinuH'diiitoly aliovo .Myiiodk Creek. 'I'liesc Jire no liti Ic (■(PiiMiliiliitnl
ill i'()iii|)iii'is(>ii with till' liultoni i>t' ilic suiiif series and with llie incUs
o.\|Mis(',(l ill tile olliiT liicalilics, liial IlifV woiiiil luir.il\ In- (•inii'lalcii
willi tliciii hytlii'ir iiliysicai cliaraclci's. Sliil, llic I'liaiiu'f t'lnni ilic
lower rocks lo tiie ii)»|)er sands and gravels is seen to he \ cry u'radiiai,
and llie series to lii' cont'(H'iiiat)ie from lop to liott^mi. If t his corri'la-
tion l)c correct, we lia\'e al)o\c .Myiiook Creek a xcry i^reat tiiickncssof
fresli-water strata <le[)osiled in liic Cpiier Ivici'iie ]ieriod. 'I'lic sec-
tion exposed must Ileal least I (1,1 Hid feci unless faults cxisi, wliich wei'c
not noted. If deposits so tliick were acluall\' I'onned in this compar-
atively short "^colofrical time, the dilTerciicc In llii' coiisolidal ioii
between the lofi and liotlom of the scries apparently depends upon
tlioconsolidatiiifi inlliieiices exerted on the lower lieds liy the weij;lit of
tlie overlyiiij,^ aeeuimilations. as well as upon the sliy:litly <:reater api
of the lower licds.
In the somewliati loosely consolidated coarse connlomeralcs in the
Lower Kaniparts, lietween .Mynook Creek and the Tanaiia, were col-
leeied roiiiaiiis of dicotyleilonous plants which were indeteiMiinalile,
liut which were <'oiisi(lere(l by Dr. Klio.vllon to be probably of the saints
aj^'e as those above noted — I'pper Koceiic
Below tli(> Mtdozikakat the first Terliar.V rocks exposed are con-
fflomerates, s^i'cen grits, and shales. Farther down the river they aro
overlain by \mnH- and liner sediments, eonsislinff of jriay sandstones
anil soft clay-shales. In the upper beds were collected frai;nienls of
wood and indetormiiuble dicotyledonous leaves and a small fern,
which, aet'ording to Dr. Knowlton, somewliat resi'iiibles I'l iiqitt'i-is
(ircticd Ileor, but probabl.v represents a new species. Dr. Knowltou
says in rcwird to these beds: "The aiie is uncertain, but from a nn —
ber of shells in tlio sanui matrix .Air. Stanton ini'liiied to call it, a.,
least provisionally. Eocene." The spe 'cs containing the fossil shells
referred to were submitted to Dr. W )all, who eharaeterizcd them
as follows;
Frosli-water gamlstono with remiiins nf vegi'tatiou. worm (?) triiclvs, ol)scuro
l)ivalve imiiressions (possiljly a small Uniol.aapecics of Giiiiioliasia, Anrylus, and
a ver.v elongated, rather nmooth nhell, which appears to lielong to thi^ Kenus Cam-
lieloiiiH.
None of these in iilentifial)le with any ilescriljeil American species as far as can
lit! juilKcil ti'oiu the material.
Thesandstoiies below Kaltagand above the Yukon delta are referred
by Dr. Dall to the same series as tho.se already described, apparently
on stratigraphieal grounds and on account of their probable conlinu-
ity with the beds on Fnalaklik River and Norton Sound, which con-
tain fossil leaves characteristic of the Keuai group.
All the occurrences which have been described, therefore, may bo
correlated with the Kenai si-rics of Dall, and mr-y be referred to the
Eocene. The rocks may be summarily described as cousisling of a
18 (JKOL, rr 3 13
\m
i: ■ - n:'
L
M
WW
\
194 (JI'.OI onv OK TIIK YUKON OOT,D DISTUICT, ALASKA.
j;rcal tliicUncss of soiiicwliiit Icioscly ciiiiMdlidutoil coii^'loini'nitoH, hiukI-
stoiK's. iiiiil sliali's. all irriiiTally (.'iccnisli in ciilnr. 'I'licy confain
(•vci\ \\ licii' (ilaiil remain^ ami t'ici|iii>iit scaiiis iif liyiiilc, and ri'sl.
lin<'i)iir<ii'Mialil\' ii|iiiM llii' iilili'i' I'di'iiiat idMN.
tiiuknkss oi' tmk kknai m:ries.
Tlic Ical'-Mraiini,'' cunirl rales, sandstones, and sliales overlying
the .Mission Creek serii's below .Mission Creek on the \iikoii were
roughly estimated, witlioiil any actual data, as heinj: Ki.ooo fci't
Ihiek. and as lieiiiir >^e\ eral I imes as tliiek as the iiiiderlyin},' .Mission
Creek series. This is a mere ^'ness, lint serves to <'()livey the imjires-
NJoii formed after viewing;' numerous extensixc exjiosiu'es alon^' the
hank of t he river. .1 list above ]\lynook ( reek t he seel ion of beds I'on-
lainiiiK tlie same s])eeies of fossil plants is at least Ih.ikhi IVet thick if
there is no faiiltin.a. iiclow the .Melo/ikakat, also, these beds occur
for many miles with a general northwest di|t, passing' upward from
conifhmierates to liner-u;i'ained sandstones and shales; and e\eii allow-
inirfora ui'cat deal of fault ini.', the actual thicdviiess of strata e\])ose(l
here must be \cry u;i'eal.
REPORT ON A COLLKCTION OF FOSSIL ri.ANTS FROM THE YCKON-
RIVKU. ALASKA. oHTAlNEl) RY MR. .1. E. SPi'RK AND PARTV
DURlN(t THE SUMMER OF IsiMi.
By F. IL Knowi.to.n.
i>r,s( liii'TioN.
This cdllcrtion. as sulnnittcil to inccdnsisti'dof nliont l-Ti spccinions. ami re])re-
sents 111 liii-iilitii's at varicms iioiiits aluiit^tlic Yukon lioni Walkers Fork of Forty
Mile Creek to tlie vieinity nf tlie iiimitli of the Koyiikuk. a (listaiice of soiiieMiii)
miles. Tli(> entire collection was carefuUv arrani;i'(l l>y Mr. Schrailer by locali-
ties, anil the iiositioii of each iudicateil on a map of the Yukon, together with the
Jirovisioual (leleriiiiiiatioii of the Keiilo;iical hori/oii.
The material is, \nifortuiiately, very imperfect, the plant remains boint; in
alumst all I'ases only fra;;meiits. The ileterminations. therefore, are more or less
doubtful, and can not have the value that is necessary for satisfactory identifica-
tion of hoiizdiis. The report ia thori'tore to be n>.i,'arded as provisional, and sub-
,iect to revision when more ])erfect material can be ot)tained.
I have given iir.st a list of the localities, witli the plants from each, relegating
the discussi,)n of their age to the end of the report.
1. Foirrv .NMI.K. NAI'cl.F.tl.N CItKKK.
Material a black carlxmaceous shale. I'ontain.s idnnt fragments, but so
imperfect as to bo of no value.
™. MISSKIX CHKKK.
Material a very black cari.onaceous shale, with minute, wholly undeter-
minable plant fragments.
a. IIKI.OW MISSIO.V CHEEK
Seipioia langsdorfii.
Ficus? alaskana? Newb.
Corylns macijuarrii? (Forbesi Heer.
Pterospermites dentatus Heer.
&
KOSSII- I'l.ANTrt. 196
4. TWKNTVtlVK MII.KH MlliVt; .MVMllllv lilKKK: Mll.l.t^lt H ( llAI. MINI".
PhniKiuitcs iiliiMkaiiii? Jlccr.
Kii'iis'.' lllil^l^llIw^.' Nt.'\vl>.
('(irylurt iiiiu'(iimrrii iTorlirs^ Ilrrr.
I'ii|mliin liiilHiiiiiniilis lli'cr.
l'l;itainis sp.
VitiH cri'iiutu'.- Hi'pr.
Cni'liitrs sp.
W(hh1.
Stems mill fr.ifimc'iita.
"i MM-I MII.KS AMIiv K MV\CM1K ( IIKKK.
NothiiiK '"111 111' iiiiiili' dill li'diM lliis iiialiM'i.il.
It. .irsr AHnvi; uit Noimi ui' \n simu i ki.i.k.
FicnHV iiliiskiiiia Xcwli.
Ciirylns iiiaciinarrii (Furlicsi llccr.
Wodd, apparmitly o<iiiiter(iiis.
7. IIKI.llW MVMXIK CHKKK, Oil limWKlN MVMMIK I IIKKK AMI TANANA.
Several small siiecimens sliowint; franmnits iil' (liciityli'iliiiKiUH leaven, but
wholly iinlpleniiiiiiilile.
^. -rillllTVI-IVK Mil. lis llI;l.dW 'lA.NAN.V.
Di<'Otyleilimims leave.s; frai;iiieiits.
Piiiiis maceliirii'.' lleer.
11, IIKI.OW Ml:l.llZIKAKAT.
Pecoiiteri.-; nrctica lleer.
Dieiitylediiiuius leaves, iiiileteniiiiiable.
Wood,
III. Mii,i;s MiiivK iiii; MuiTii ur iiii: KuviKru.
Traces 111' iirvtaiiic reniaiiis. Iiiit ilimhil'ul plant trai,Miients
niscissiD.s' 111' Aiii'. .\s iMiHArKii hy im.ants.
if nil value
In regard to localities 1 and -'. olivionsly notliin;; can lie said. Tliey are plant
t'rat;iiients. but witliout cliaraeters. The same may lie said of localities ."i and 1(1.
The localities :!. 4, and (! may be <'onsiilei-ed tiii;eiher. I'^roni the lirst ol these
(I!, below Mission ('. -ek), four species have been idi.'ntified. Locality I (Miller's
coal mine) has yielded five siiecies iiiul five or six (mestiiinalile fragments, while
locality!) laliove Mey nook ( 'nek) has afforded two sjiecies. The combined list
from these three localities is only seven named species, as follows:
Sequoia langsdortii.
Pliragmites alaskanii.
Corylus maciiuarrii.
Populus balsainoides.
Ficus alaskaiia.
Pterospermites den? "us. i
Vitis crenata.
These three localities appi c to be similar in age, since at least two species
Coryliix iiKiniHiirrii and Fii s iihialiiiiKi) are found in all of them. These seven
species are all well-known forms, being found in abnndauce in the vicinity of the
Mackenzie River and various parts of Alaska. In age they belong to what has long
1 b
IDfi
(iEOI.OGY OF THE YUKON GOLD IHSTKICT, ALASKA.
I
been fiillcil tlie Arctic Miocene, but wliicli late iiivcstiBiitiniis liave sluiwii is prob-
ably l'iii)er Kucoiie. A majority of these species were also t'oimil by McCoiinell
in liis explcjratioMs in tlie Yul»on ami Mackenzie basins near tlie mouth of Bear
River.' They were referred by Sir William Dawscju to the liaramiu, but it should
Ix' remembered that the ranailian Laramie c<irris|ioiids to the Fort ITiiion Ki'onp
of United States jjeolofjists and not to our (.'retaceous or true Laramie. There is
lUidoubtedly a stroiiu resemblance between the Hora of Alaska. Mackenzie, etc.,
and the Fort Union ll^>ra. but F incline to rei^ard the northern Horas as a little
higher, therefore jirobably Upper Eocene in a.Lfc. They can not possibly be Cre-
taceous.
Locality T dielow Mynook Creek i alfords only frairments of dicotyle<l()ns. but
the aue is probably siiuil.-ir to the a,i;e of those last considered.
Tlie specimens from locality "< ('■'<'> miles below Taiiana) are also fra};nients of
dicotyledons, but none surticient for identification. There are sevon'l finely pre-
served cones that appear to be the same as Ileor's Piiiiis iiiiicfliiril. The a,i,'e is
Pliocene, or possibly upper Miocene
Tlie only form from locality 1) (below Jlelozikakat) that I have been able to
determine is a small fern somewhat i-esemblinf.; I'trajih'rin drcticd Heer, but proba-
l)ly representing' a new sjiecies. The age is uncertain, l)ut from a number of
shells in the same matri.x Mr. Stanton inclines to call it. at least provisionally,
Eocene.
THE NULATO SANDSTONES.
'i'lic Niiliito I'ocks have already been (loscrilied by Dr. Dall.- Tlicy
(•(insisl of iiiariiic Mioct'iic saiulstdiics and slialo.s wliicli (ivcrlic tlie
rocks of llii' Kciiai gi-oupaiid arc (>.\[)os('d aloii;;: tlic Yukon IVoni near
KaltafrtoflicKoyiikiikMoiiiitaiii. 'IMicsi'l^'dsaroortenripiilc-inarkcd,
and I'otitain vcjrctablc frairmt'iUs. In issi; |)i'. Dall obtaincil Cossil.s
r('l)ios(Mitiny: the ij;cni'i'a Moiliola, 'IVllina, .'\lvtiliis, (iaslrocliii'iia, and
.■\lya.
About Jii miles above llie mouth of llio Koynknk, noai'ly oi>posito
tlit'Twiu Mouiilains. isa stccpcliiroii the rijflit-hand sidcof tlio Yukon
fisiiiu: 1o a lu'lifht of ;)(I0 iVcl or inoic. Here the Ix'ds arc well folded
and have a {joneral strike east and west. They eonsi.st of blue-
.tfray siialy liinestoiie.s and sandstones, contiiiuiiig doubtful plant trtig-
nients ami ea^ls of marine shells. Speeiitiens eolleeted from this
locality were submitted to Dr. \V. II. DfiU, who eharaeterizod them as
follows;
Marine saiid.stone, jiroliably Miocene, with poorly preserved casts of Thracia
(ilycimeris, Tellina (sub^. Angelusi, Macoma. Yoldia (or a yoldiform Macoma),
Xiicula, a species with heavy shell, and a partial imprint of a naticoid shell.
THE TWELVEMILR AND PORCUPINE BEDS.
TWELVEMILE HEDS.
Twelremile Creek is one of the bran<'hes of Mission Creek. Xear
the point of junetion of these two stri-ams are expo.sed in niimei'oti.s
outcrops slifjjhtly consolidated and eoarse-bedde<I aravcls and sands
' Ann. Kept. Ui'ol. Xiit. Hist. Survey Canailii. Vol. IV, Isss Sli. p. 23 D.
"Bull. U, H, Ueul, Survey No. 81. rerrfliitiiui Papers— Xeorem-. p. 24T.
siTiin.]
THK TWELVEMILK AND PORCL'PINE HKDS.
i;»7
k
viiifh carry seams t)t' ligl!t-l)n(\vn sandy 'iij;niu'. KraLniicnts ul' wood,
t'onsiderahly alloi'cd, liaviiif; a dianictcr of as iiiucli as I'l iiiclii's. aro
found, but no fossil leaves or shells. Oeeasional pieees of black,
sliinv lijjnlte, such as is found in the Kenai series, and less ahun-
■lanlly in 11\e Mission t'reek series, occur, hut in such a manner as lo
leail to the suspicion that they are fra^rnients ili lived from tl.ese older
rocks. The l)eds are sli;;htiy folded, iiaviny: a dip of about -J" . Near
the month of Twelvemile Creek the diji is southward, though abcuit a
mile above Twelvemile (.'retd<, on .Mission (reck, tlie dip is to tlu'
north, tjioujih tiu' strike remains nearly the same: thus a siiallow
.synelinc is inaicate<l.
The rocks of the .Mission C'l'cek series, which underlie these IhmIs. are
shari)ly folded, and altliou,ij;h no actual contact was seen, it is im-oI)-
able tliat an unconformity exists. I'xdow .Mission (reek the rocks of
the Kenai series are well indurated, forniiufj; compact conglomerates
and samlstones. ami they are apparently confornmble with the rocks
of the nnderlyin.u' Mission Creek series, with which they are infolded.
It apiiears, therefore, that the Twelvemile beds can not Ix- correlate(l
with the Kenai series, and yet they are old(>r than the horizont.d
Pleistocene silts an('. <;i'av(ds which are exiKised all alonjr tiie<-ourse
of tin- Vukon. They maybe provisionally refei'rcd to the Miocene oi'
Pliocene. From theii' nature they seem to be fresh-water lake
deposits. 'I'he nuii'ine .Miocene sandstones described at Xulato are
littoral, as is shown by the ve^'ctalile reuuiins, ripple-marks, and mud-
cracks which they contain, .so that at the time of ,heir <leposition it
is i)robable that that portion of the country throu,u:h which the upper
])arl of .Mission Creek now cuts was laud, where there may have been
lake.-, in wliich such deposits as the Twelvemile beds were laid down.
I'orurriNK hi:ds.
On Porcn|)iiu^ Tiiver, between the mouth of the Driftwood Kiver
ami the head of Ihe Ramparts, is a series of bi'ds which .Mr. K. (i.
.AlcConiu'll' has described as comiMised of "yellowish and whitish
san(h and sandsloncs, inteilieddod with a jirayish rather hard coii-
filomcrate i.iade up of (piartz iiebbles, fra.irmenis of shale, and scales
of a silvery micaceous schist;" in other localities these beils consist
of '"soft scai'cel\- strati tied v.hitish and yellowish clays and sands."
Xo fo.ssils were touud in these beds, but lhe_\ are umMPuformably
underlain by liluish shali's and sandstones, which contain numerous
impressi(Uis of a larjie Inoceramus, and which ai-e probalily, in jiart
at least, of Cretaceous aii'e. Prom these stratiyraphii'al relations Mr.
^IcConnell corrc.ates the overlyini;- series with the Jiear River beils
of the Macken/.u". At the lower cud of the Lowim' Ramiiartsof the
Poi'cupine. .just above the termiimti(Ui of the flats which occupy both
banks of the v'wi'v 'or (Ht miles above its mouth, Ihe same sei'ies of
' Ann. Ki'Pt O.'..!. .N;it. l\i-t. Survi'v. Caiiiiila. i,.'w >.'1m.-. Vnl. IV. I>'N« .■-'.i. p. IJTD.
m^"
Rit-;
P
liff
ill
1!).S
(.Kill.OCY 1)1' TIIR YUKON OOI.I) DISTHICT, ALASKA.
ycllowisli tiiid lin;lit-ic(l(lisli sands and flays was obsi-rvcd by Mr.
McConni'U, and Ihto also tlicy nvcrlic unconforniahly dark shales
wliich arc [H'oMably ('r.-tai lis. 'I'lic l>oar l{iv(M' l)i;ds Cdiitaiii abun-
dant remains of flora, wliicli were ('xamincd by Sir William Dawson
an<l lii'ld by liini lo iiidica(c a l.araniic (Fort I'nion or Eocene of
Uiiile(l Stales jrcoloj^isls) aji'c Cor tile beds. On siral i^'rajiliical and
lillioioflical grounds, liowcvor, Mr. ^McCIonnell ai)[)ears to cntci'taiii
siMiic doubt as to the cori'cctnoss of this correlation. He says: '
Till' 1)im1s i)f this Tertiary Ixisin iiro cviilimtly Intnistriiliii tlii'ir oriKin. iiml Imth
in litlioldgicat rliiiiactiT iiml striUi%'ni|>hii-al position Imvi' a uuu'li clostM- rcscni-
lilaiicc to the Miocciio (Wliite Rivori of tlio Cyipri'ss Hills and ncigliboring areas
than to the I.araniie with iiieh their fossil flora eorrela.es them. Like tho
Cypress Hills lieils. they are i liaracterized by their irrei;iilar (lejiosition, by their
slight indiij-ation. and by the birno proiiortion of gravel and ])ebble beds which
they contain, and a further degree of relatimisliip is evidenced by the fact tliat
they both rest unconforniably on the beds beneath. Mere lithological similarity
in the case of two such widely separated cletrital terraiies is of very little vulne in
determining age. and in the jiresent instance might be disregarded were it not
sujiported by the more iiiiportant feature of a corresponding structural break. In
tlie area of thetxveat Plains, and even in tlie Rocky Mountains, tlu^ Laramie is
everywhere conformable to the {'retaceous beds below, but sustains a discordant
relation to theoverlying Tertiaries.and it has been found that its termination was
synchroiioMs with a widespread elevation of the land and the formation of fresli-
waler lakes 'n which the succeeding deposits were laid down. At the moutli of
the Bear Hivv r, instead of a confonuable pa.ssage from the t'retaceons the Ter-
tiary, we have (evidence that the '' inner was elevated and sulijected to a ,)roloiigeil
d(>nudation before tho latter was (h'posited. In order to reconcile the stratigraph-
ical position of me Rear River beds with a Laramie age. it will tlierefore be neces-
sary to assume that this part of the continent was, toward the end of the Creta-
ceous period, affected by extensive movements of elevation and depression in
which tlie central part did not participate.
CORRELATION'.
It is the opinion of the writer that the Tertiary beds on the T'oreii-
pine, described liy .McConncll, are of the .same ajrc as the 'rwelveiiiilG
beds.jus* described. Liketh ' Porcupine J{iveraii(l Hear River beds,
the Twelveniile beds rest unconforniably on the older rocks, in this
case upon dark shales, which have been called the Mission Creek
series, and in which ]\[r. jMct'onnell foundth(> fossil . I (/fvV/a luoNqiien-
.s'/.s var. i-oiicnitrifd, thus sliowinfr that they are, in i)art at least. Cre-
taceous. The same fossil is found in certain of tlii^ dark shiily rocits
which uiiderli(> tlie slitflitly consolidated Tertiary beds on the Porcu-
pine. I.itlii .onically and in dcfrree of ii. duration the Twelveniile
beds reseiiiole closely the I'orcupine beds, and in both regions they
have suil'ored a very slight amount of folding or tilting. All, more-
over, appear to be hike deposits.
It has already been reciilled how below ,>[ission Creek there o\erlies
the heavily folded .Mission Creek .series, in ai)]iareiit conformity, a
series of heavy conglomerates ami shales carrying i)lants which are
I l)|i. c'it., || IKII)
m
^w
TIIK I'.U.ISADKS liiNCI.oMHHATE.
lll'.l
ODiisidorcd by Dr. Km twit on lo idciitil'y I lit- scries ;is of the K nc :[\ii\
Botwci'ii tlit'sc Kdcciic beds of llif Kciiai UTcnii) aiiil llic iicailx lidii-
zontal Twclvcmik' beds there is tberelore an al(ril|pt iiiiiMiiii'iiiiiiil y,
aud the did'ert'iit'o in dcgrue of eojisdiidation between the two tnnna-
tions is so fii'Ciiti tlial in tlio field the ])()ssibility oC their correlal inn,
even in a ueiieral way, does not snirj^esl itself, sinee the 'I'welveniile
beds appear certaiidy nineh yoimiier. If the Twelveinile and tlie
Pori'iipino beds, therefore, are still considered Eocein', wc must accept,
t he coiisecinenee, already iiointed out liy Mr. ^fcConnoll, of a judfoiind
tinconl'orinity separaf ill}; tlie dilTcrent cihicIis of tlieKoceiic period in
this region. Since, however, if appears to the writer that the classi-
fication of the i?ear Kiver beds as Ka.aiuie by Sir William Dawson
(or as I'lipor Koeono by Dr. Knowlton) rests on data whi<'h, hi>wc\er
sn^jfestive, are not finally conclusive, it soems that the evidence
atl'ordeil by sf rati.ni'a|)hy and lit holoiry shoidd be considered, and thai
at least the ])ossibility of a .Miocene aire for the Twelvemile and I'or-
cxipini' lie<ls should be admitted. Certainly, in an> di\ isina of the
ro<'U formations, t hese l)eds must be scjiaratcd from the undi'rlyinu
Keuai series, and thoyai'O therefore uutppcd separately in this report.
I
:1 '.
THE PALISADES CONGLOMERATES.
On the left bank of the Yukon, about :>•'> miles below (he moulli of
the Tanana, clifl's of .silt and ura\cl rise to a heijihl of |."io feet. 'I'liis
V'J'*''^*:'<K'K^.
I'll;. It. — Exiinsuro of PaIls(i(it'S('onjrloin."*ato iiiuti'rlyini; silts.
locality has been named the Palisades, but on account <if the occur-
rence in the silt of abundaiU bones of tin- mammoth and other larjri*
mainnuils, it is more popularly known as the " Uoncyard."" The sills
also contain li|j;nite beds and small land and i'resli-watcr shells, and
are of I'leistocene aye. About a iiule btdow the bcLrininnjr o.f the silt
bl nil's the heifrht of tiie vertical exposure changes from l.")(Mo 2(H> feel,
the increase beinj; apparently caused by a fault which is visible in the
face ()f the bliilVs, and which u[)thrusts the dowii-ri\cr porti(Ui The
fault is a normal one, and the silts of Ihe iii)strcam side are seen to be
ii])turned atrainst the fault |)lane. (See fig. 11.) On the downs! ream
side of the fault there is brought up a lower and more con.solidated
ij; ■■ y
200 GI'.OI.OCY OF TIIK YUKON GOLD DISTRICT, ALASKA.
bt'il wliicli midcrlics t lie sills. Tliis ikmv bed is i)iiro wliito, hpinjjcom-
jmisimI .)f clean sand iiiKJ woil-wiislicd ])('bl)l('S. It is strongly cross-
lu'ddi'd. and foiilains inucli woody matlcr— sticks, lojrs, t^tc. — in a
condition between wood and lignite. Manyof these woody layers are
stee]ily inclined, bcinir cross bcchb'd witji tlie sandstone. This l)ed
is very Kent ly arclied and has a liarely ])erce[)lible dip downstream.
It is i)artly indnrated, so that while it yields with comparative ease
to a pick, it is firm en.nij;h to stand in solid, nearly perpendicular
clilTs. iuid falls in ffreat slabs.
In the materials <'i)Uccted from the woody layers Dr. Knowlton
found fra^nnents of dicotyledon.s, but, none sullicientlly distinct for
identifieation. Many of the layer.s are full of finely preserved cones,
Avhich, aecording to ])r. Knowlton, appear to be the sanu^ as Heer's
/V/(//.s iiiiircJiirIi, and from these he infers that the ago is riiocene, or
po.ssibly Upper Miocene.
THE YUKON SILTS.
i.ii '!
Yr'KOX FLATS.
ThrouKliDUt nearly its whole course the Vukcm flows throujili an
un.iilaciated country. The great eonlilleran glaeiei', which has been
iiiaile known <'hielly by the work of Dr. (J. 'SI. Dawson, and which
occui)icd liritisli ('oluml)ia west of the Hocky ^[ountain.s au<l tlio
extreme southern jiari of Alaska, has now shrunk into liie many
snudl sejiarate ulacicrs which form such interestinj; features in the
scenery of the .Maskan coast. This glacier, however, never extended
farther north than a iioint which on the Vtikon has been determined
as just above the Junction of the T.ewes witli the liig Salmon Kiver.
This fact has been eonrn'nu'<l by the observations of Dawson, ]\Iet'on-
nell, ]ius>'ll, and Hayes. From its source to its mouth the Yukon
flows in narrow, dee]) valleys; and where the country has been gla-
ciatinl, as along the l.ewes above the ]>ig Salmon ]{iver, th<> hills are
•somewliat rounded and the toi)ography suggests gl.cial action. Here
also the rivei' sometimes slackens, and forms long, narrow lakes, whose
shores are generjilly steep and often in'ecii)itous and whose basins are
siin])ly jjortions of the ancient rivei- valley which have been dammed
in one way or another. North of the limit of glaciation the seeiiei'y
is nujre bold and pietures([Ue, and the river flows through a deep and
often liarrow valley with stee]) and rugged walls which are eonsj)icu-
onsly terraced, the lower terraces being formed of gravels or silts,
while t hi' higher ones are earved out of the rocks. 'Wiis is the nat ure
of the valley from the Uig Salmon IJivei- to Circle City, a distance of
4110 miles or more.
About ."() or (10 miles above Circle City the valley of the Yukon
enlarges, so that there is ofli'n a llood-plain .several miles in width,
which is swampy ami covered with moss and .stunied sjjruce and cot-
1
i.SJ :
sprnnO
THE YUKON SII.TS.
201
tonwood. The cuts iilonu the l)aiik of llic river show that this Hood-
plain (l('iK)sit isi'diiiposcii mostly of st falifii'd sands witii some j^'iavcls.
Fai'tht'i'down the river the width oft lie xallcy still inc-reasi's. Almut
5 or i) nules above Circle City the sleep wall on the left side suddenly
disappears, and is replaced bj' low, perfectly Hal banks, which stretch
away to the southwest Jo or liO miles to the distant low mountains.
The high rock blult on the ri^dit bank persists a little lon.i,'er, but near
Circle City this loo disapi)ears. With tlic recession of the conliniufi
rock walls the river broadens out and wanders slowly throufrh the
flats, formins; long islands with channels or sloughs between. Thus
the Vukoii is said to be 7 ndles wide at Cir(de City, and un<l<i\ibtedly
the combined width of its several channels is nearly or (piite that.
Xortheast and northwest from Circle City the sky line is low and per-
fect ly level, being formed, indeed, by swampy land, such as const it iiles
the banks at this point. To the northwest, beyond the Hats, lies a spur
of pictures(|ue mountains. Uelow Cinde City the river Hows for l'.W
miles or so through this perfectly level country. For a large jmrt of
this distance the higher land which bounds tlio swam](\ Hats is so far
away as to be bidow the horizon, but at times outlines of hills may ho
seen. At its Junction with the I'orcupiiu' the Yukon turns nearly at
right angle and flows to the southwest, and the nature of the country
on both sides continues the sanu^ as far as the trading i)ost known as
Ftn-t Hamlin.
In this flat region the river spreadsout very broadly, with numerous
channels and islands. (See 1*1. XXXV.) There was no hard rock
observed at any point, the islands and the banks of the river being
perfectly level and composed of horizontally stratilied sands and line
gravels. The islands are of various heights; at thetimeof the writer's
observation (the latter part of August) the highest ones stood at an
av(>r!ig<' of •■> to S feet above tlu' river, and Were composed in largo
part of dark-colored silt with some coarser sands ami tine gravels.
These higher islands are covered with a heavy growth of spriu'c: the
somewhat lower ones, which are nuide up of sand and gravel rather
than of silt, have a young growth of cottiniwood. while tho gravel bars
and sand sjiits, which rise only a few inches or a foot above the river,
are hare or have but a scanty growth of young vegetation. So
numerous ai'c the channels in tlH> river that one is rarely con lident
of having found the true bank; indeed, between Circle City and Fort
Yukon our i)arty was never certain about this point. From Fort
Yukon to Fort Hamlin, however, the nuiin current of the river Hows
along the right bank, which it does indeeil for the whole length of tho
river between Fort Yuk«m and tho si'a, as has already been noted by
Kiissell; and in this way the .stream is continually eroding dejiosits
which have been >indLslurbed for a long [)eriod. I'.etween I ort Yukon
and Fort Hamlin the boatman drifting down the river naturally fol-
lows the swiftest current, and tiuu'efore keeps always close to the right
11
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20-j
Ol.dl.DOY OF Tlir. YUKON fiOI.I) DISTKICT, ALASKA.
liaiiks. Till' hunks arc usually liit^licr lliaii any of tlu' islands in tlic
river, vcacliintr (i'''cn :>n or |o tVct above the water at tiie time of
otir observation. Like many of tlie islainls, they are built n|) mainly
of horizontally siratilied sill with frequent layers of jrravel. They
are eovered witli a thiek ^'rowlli of trees, many of wliieli are evidently
of eoiisiderable ayre, and on the surface is a coatiiifj; of deep moss,
wliich is not found .n tlic lower islands. 'I'licre also appears 1o be an
abscn( f the driftwood ami oilier evidences of yearly inuiidalictn
which eharacleri/.c these islan<ls.
'{'he Hals end e\en more abruptly than the\' bejrin. They termi-
nate sharply about a mile above I'"ort llamlin at a line of steep, bare,
rock hills which rise to a (miiumioii level estimated as Hdii or 7i"> feet,
above tile ri\ci'. There is no not u-cable iiarrowiiijf of the \alley as
the slreani approaches tliese hills, but the hills lie transversely to
the coiiise ol' the river, like a solid wall thrown up to hinder its
adsance. I'p to the ycyy point of reaching; this liai'rier the ri\cr
colli in lies to be very broad, willi inaiiy islanils. Iioth tlic islam Is and
the banks ari' low and ]ierfecily lev<'l, and are built np entirely of
u'lavel capped with silt, exactly like the banks and islands for I'.'iO
miles above. Tn the silts numerous shells of small f^asteropods were
found, belontriii},' to land and frosli-water siiecies. all of which are
liviii;; in this region at pi'cseiil, aeeoi'diiig to Dr. W. ]I Dall. Here,
ns ffirtlior ii[> the stream, the true banks of IIk- river are higher than
the numerous islands, and there is no evidence that they have been
inundated by the river Hoods for a long period, since at the time of
oliservation they wore about '.io feet above the I'iver, and appar<'iitly
above extreme high water. ()!i leaving the flats the ri\'er imme-
diately enters a narrow ennyoii, the walls of which rise steeply ui) to
tlie general level of the hills. PI. XXXA'I is a ])hotograp]i of the
lower end of the Hats and the beginning of the Lower Uamparts. In
the right foreground is the silt bank of the river, 'i'lio river, here
cutting its right bank as nsiial, is undermining tli(> silts, so that they
fall into lli(> water continually, carrying with them their vegetation.
In the center of the picture is the narrow, eanyon-liko valley into
which the river plunges on leaving the flats, and the level top of the
hills in which this valley is cut is well shown. Beyond this level
surface are low, rounded hills wliieh rise above the usual lev(d to a
considerable heiglit, and in the distance are steeper and higher
mountains.
Heturniiig now to the upper end of the flats, we find that their
boundary on leaving the Yukon runs olf at, a right angle to the river
for a few miles, ami then skirts the base of the Crazy ^Mountains.
Eight miles southwest of Circle City is a stream of considerable size,
known as Hirch Creek, meandering through tlie flats. This stream,
however, c(Uitiniies to hold a course nearly iiarallel with the genei'al
trend of the Yukon, so that the distance is iiearlv :.'oh miles from this
Mi
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• 13
■PURR.)
THi; YIKON SII.TS.
.'(»;{
|H)iiit to where it Jiiiiis tlie lai'irer river .sDiiie ijlstain'e lieinw tlie irreal,
beliil. I'l'idii tlie point on IJireli Creek (lirt-fl iy o|i|)(i>iie I iiclc City
the Ihits extend haeivwiiri! in a sontlieas! ilireftion, t'oiiiiinn' a lonir,
lii'oail arnL. IxMindeii in' hiuili and hiliy land in all dii-eei ions except,
the nort hwest. As is e\ ci'ywlieri' the ease, t he liiM' of Jiinet ion nt' t li(»
ilats with the honniHii;,' liiudier land is very dist inelly inarkeii, and
lias been followed alon^^ this arm in some detail, since it is in this
rcfiioii that the placer ^travels of jiireii Creek, uliieh are ihe most
prolitalile thus far diseoverecl in Ilie Niikoii district, are found.
^^'hen thus t'ollowccl, the line is tonnd to he extremely irre;;iilai',
liranchiMn' olV into arms w hich run for some distance up \ alleys deeply
cut in the hilis. '{'he to|M)^'raphical sketch map of the Mirch Cr ^ek
iiiinin^r district ( I'l. I,) ,L;ives some idea of the Junction of these j-'lats
with the siirroiindiiifx hills. The bottom of the Ilats <M)nsists of
swampy ground, with dry, low swells and small, shallow lakes,
'riirou^rh this level country llirch Creek winds with complicaled
meanders. Narrow, cnrvinu; lakes, such as are shown on the map near
'rwehcniile cache, are olil cut-oil's <if ilie stream, and are now bein;^
ji;radually coiiverte(l into swani]is by enci'oachiiif; ve;ietation. Other
lakes, sueli as ^[edicine Lak<', liave had an oritrin independent of tho
stream, beiiifj; shallow bodies of watei fillinu: slight depressions in tho
surface, and these also are surroniu'ied by a thick urowlli of rapi<ll.v
incrcasinfj; mo.ss and wator-lovinj^' |)lants.
J>et ween this swampy eouiitry and the base of the boivlcrinj; hills
is a b(dt several miles wiib-, which has a uniform, very slij;lil slopo
awa.v from the liills and which is ordinaril.v dry. Tiiis belt occupies
the mo.st of tho valley of Crooked Creek above lloj;"eiii Junction, and
has also boon continuously observed aloiij;' the base of the liills
botweoii Central House and tlio Twelvoinil(> caclio. (Soo PI. .\I,IX.)
The surface of this belt exhibits very slijrht undulations, which
are not noticed in the perfectly level countiy m<n'e remote from
the hills. Tho materials of which it is composed are schists and
firanito, like the rocks exposed in i)la('0 on the ad.jacent hills, but
here these I'ocks occur only in suban}iular or slitrlitly waterworn fraj^-
monts, iiileil together with often some sng^'ost ion of rude stratilica-
tion. 'I'ho streams which How over this belt, such as Hofi'em Creek,
Boulder Crook, Albert Creek, Quartz Crook, and otliors, have no
delinite valle.vs, but havecai'ved mere furrows on the surfaci", tlinmirh
which the.v How down to the swampy (lats. Tliest; streams all orij^inate
in the hills which rise abruptly from the lowland. Above tho line of
.junction of th(* flats with the hills each stream, which before has
llowed in a little furrow on the surface of the nearly level accumula-
tion of rock frajiments, lies in the bottom of a V-sliaped valley carved
deeply in solid rook; and in this valley there is little fraj;montal
nmtoi'ial exoojjt a small aocunudation of frravels, which lie in tho bot-
tom and which are in many iilaces rich in jrold.
'If:
\\i
204
(iKOI.onV OK THK YIKON (iol.ll DISIKICT. ALASKA.
Tlii'si' flats cxfinl up tlic I'nrciipinc jil»)\ i' ils jiiiicl ion with llio
Yukon f'di- 7") or |ihi iiiilcs, lis iiolcd hy Uiisscll ' and .McConncIl,-' and
Ik'Ic till' idiMiaricrs of llii' di'|iosil an- tin- same as noti'd aloii;.' tlio
\'iikoii, till- iiialiTial lii-iii;; slialilii'd silts, sands, and ;;ia\ids, ofton
wliowiiin rioss-linl inj;. 'I'lii' I'Mi'iil ol' Ilii' Mats is, t luToforc, not tar
I'loiii tliat sliowii on till- iiiap, wlii'i'i- llii'v ai'i' si-i'ii to ri'ai'li in a nortli-
t-asl diri'i'lioii lor alioiit -Imi mill's, wliili' tlii'ii- width, taken in a north-
wi'st-soiitlieast diii'clion, is prolialily oxer |i"i mill's.
The sliapi' of till" ^'real silt. sand, ami ^'ravi'l deposit, as thus out-
lined iminedialidy su^f,"''*''* 'I'e lormer existeiiee of a ;rieat lake, in
the liollom of wliii'li these sediments aeeiimulated. and the sharply
lie lined hills whieh I'ise e\ei'y where distinctly and abruptly from theso
JIat deposits have all the appearanee of shore lines. The siidih'ii
chanj^ein tlie eliaraeliM' of the streams when Ihey enter the Hats from
the hill\' country, or leave the flats and enter the hills a>;ain, is also
very stroll;; e\ idea f the existence of such a body of water, for at
the Junction the canyon-like valleys suddenly and completely disap-
pear and tlio river wanders farand wide ovei' the sandy deposits, into
whieh it has cut the merest indentations.
Tile belt of ^rently slo|)inu'. coarse, sli;,ditly stratified material, more-
iiver, which has been described as lyin;; between the swampy lowland
and the hills in the iiii'ch Creek mining:' district can be accounted for
only bytiie siijiposition that it is composed of torrential material,
hrouiihl down by the mountain streams which have carved such deep
valleys in the surrounding hills, and deposited alon^ the shore of a
shallow body of standing,' water. The materials of this fi'a;.M>ieiital
deposit, as has been remarked, corresiiond with the i ks found in the
valleys of the inounlain streams.
.Ml the central portion of these flats, which 's remote from the
Khores, is of fine malerial, chielly silt, \\ the uiesentt iniethe \'ukou
rises annually into floods, iind o\erlow ishiiids deposits repent oil layers
of fine sediment, which ill many cases have . ■ciiiiiiilated to a thick-
ness of several feet. These recent llood-pl.iiii i'.i']iosits are often not
disi iii;;iiishable from the silts which form the banks of the river, but
the latter ordinarily form blull'sof ;;i'eater hei^cht. Thetfrowth of low
islands by yearly additions can be studied in detail alonu; this jiart of
the ^■ukoll. and the evideiii f ^rrowtli is generally seen in nuincroiiH
layers of woody or i>eaty matter, which alternate with the layers of
silt and represent each a suinnier's^jrowthof ve;retatioii, whileilielast
layer is i|iiite fresh and is only partially covered by certain rapidly
jtrowin^j' [ilaiits.
The presence of driftwood and the marks of recent ^routriiiu; by
floating;' ice are also freiiiient evidences of late inundation. In the
higher deposits along the banks, however, the .silt is frequently very
I X(it<"i i>ii tlu' siirfac ifi'olKKy <>f -Maskii: Bull Oi'ol. S.«;, Ami-ricii.Vol. I. p. 112.
'Ann. Kept, iivul Xiit. Hist Survey OmiKiii. lSSN-««. Vol. IV. pp. 2TD. 1;BD.
TlIK VIKON SII.TS.
205
111 irk, lias Hull' evil Iciicc ul'^i ralilic'iil idii, ami i> « i! limii i Ih' iimiiic'ichis
lilllc scains of wcmhIv niallci' wliidi mark tin annual nmwili nf i|ii>
lower islamis, wliilc llic sill liH'r is il('c|)l\ con cicil wiili luuss ami liill-
;;ro\Mi I lees ami hiislii's, ami has cn idi'iil ly iiol I n llooilcd lor a \i'iy
Ion;;' period. II seems eeiiain, llierel'ore, I hat if these latter are llood-
plaiii de|)(tsits. they were formed at a time when the irt-neral level of
the ri\'er was hiuher than it now is, or lie fore ii li.id eiii mi i lei ply inio
itseliannel: and from the eharaeters nieiitioned it seems |irolialili-
that llieyare lake sediments. .Mr. I{n>.-'ell has siiir^,'esleil that the
w hole material of I ho Flats is a \ ast flood-plain de|iosil, spread mil liy
I he Yukon in eonseinieii f the river ha \' in;: been dammed up liy an
elevation of I he lianiiiarts, I tut tlieal)i'U|il terminal ion of I he upper end
of the Hats as well is the lower end, and the e\ idenees of shore-lines
alreail,\' ;j;iven, seem to exclude this hypothesis.
Coiicerniii}; the Hat deposits alon^r the lower part of the roiciipiiie,
Mr. .MeConiiell ' remarks:
This iilaiii liiis ii width in it.s wiilest jiart nf t'liUy !io mill's. Siotiniis arr (.'iit
tlirniiK'i it i" ilill'iTi'iit iliroctiiiiis liy tlic I'linuiiiiii' anil Pilly-Yilkoii. anil sliiiw it
tn hi' unilorlain thnnifilnmt liy Htratifinl sauils ami silt.s, otirii slmwin;; falso
bt'dilinf,' ami with iiccasional layern nf gravel. Tim latter aii|ii'ariiil tn lic'iuno
filler Kraini'il and nf Iuhs relativo inipnrtanci' tnward the ci'iiter nf the area. Tho
size nf the iilaiii. its iinifonuity. and the I'haiacter <>f tho lieds which iiiiderlii' it,
sUKfii'st a delta nriKin. ami cnrrelate it with the Inwlands at presfut in course nf
fiiniiatiiin at the inniith nf Slave Kiver, in Great Slave Lake.
The period at which this lak(! e.visteil must he \ery r nt, for the
fossils ;"oiiii(l ill tho silt all belong; to liviiij; s])eeies. Another piece of
evidence is foiinil in the sliy-lit anioimt of erosion which streams have
iu mplished aloiij; the ed^cs of the basin. In the /one of ni;,\|.|s
and lorrontiiil iimtoi'ials, which has been described as borderinjr the
old shores in tho liirch Creek district, tho stroanis which How from
tho moiiiitaiiis run in constant, narrow cliannols, yet they have cut
(iidy iiioro furrows, which can not be detecled in a ncnoral survey of
the landso)ii)o.
The samo phenoiiionon was noted in the Lower Kaniparls, below Fort
Ilanilin. Tin; river hero flows thronyh a narrow valley, with steep
walls, which aro distinctly terraced all the way tiii to a nearly level
l)lain <1(H» or 70n foot above Iho stream. In those walls lateral j;ul'i"s
runninji at rif,'ht angles to the main trend of the vaUey have bo^nin
to form, but they aro so iniporfcct in thoir dovolopniont that they
must hfive bcfinn very rocontly, for the most marked ones aro only
(loop V-shaped notches. Another snjrj;estion is ollVred by the |iosi-
tioii of tho river in tho flats. Tho erosion of the ri^dit bank from
Fort Vtdion to Fort Hamlin is very rapid, and it follows that the
stream niiist bo ra|)idly pnshinj: northwestward. The rapidity of
tills prottress can be fully a])preeiated only by one who has traveled
1 Op. lit., p. j: u.
I:.
;tH
IM
l>()(i
(ir.oi.ocii- OF THE vrKON (ioi.n disthict, ai.aska.
tihma tlic l>;itik of lilt' riv.T iiiid hciinl tlic t'oiiliiiiial splasli of the
water, willi llic ruiiililiiif,' of the sill hanks and Ihc cracklin.ir of Irces
as the nnik'r-cut porlions fall. Al lliis rale il is .vidcnt llial in a
very shoi'l, time tln^ slrcani will have ])nslicd its way I'losc ui) to the
nortliwcsterii border of tlie ilals, and the fael that it has not yet done
so is evidence of llit niparalively brief jHiird that it lias been
workini;-. Tlial it lias already traveled some distanec is liinted at by
Ihe fael that il is al iiresent a|)|)ro.\iinately Ihreo times as far iTom
the southeastern side of llie flats as from the northwestern side.
I'OKT IIAMI.IN TO MVNOOK (KEEK.
About lialfway between Fort Hamlin and Ntynook Creok, in the
vieinitv of b'ay Ki\er. tlie vall(>y broadens out. formini; low Hats,
wliieli streteh S or in miles away to low niounlains. wiiieh are dis-
tiiiftly and evenly tenaeed (see 1"'. >'L). Kelow this iioint the river
makes a sharp turn lo the left, as shown on ilie map. and enters a
narrow \alley. Ojiposile Mynook (reek are narrow Hats aiiaiii. (>n
the left bank of the ^■uke.l. Just abo\e]Myiiook ('ri'ek, is a irreat tliiek-
I'.ess of steeply diiijiiiiir Kenai bods, as alrea'!;. desi ribeil. These arc
exposed in a steep iiliilV about (01) feet hiiili, of whieli they constnilto
tlie lower l(Miorl'0i1 feet: uueonforiiiably overlyinji them are ."i or 10
feet of hori/onlalh' bedded ui'avels and mud, and then :'i«i or odO feet
if sills lil
those loiind 111 Ihe
Its. In I'lese sills fossils were
lected, which were ideiititied by Dr. W. II. I>.lll as Si/ci-imd fln'ijsi.
\Vest.. \'iilfitl(i sliici rii Sa\'.. an
d LiiiiiKi (I jiii
/(/.S//7.S Mull. All these
species are found liviiii;' in the reirion at present.
.M"N('T1(1N dl" TANAN.\ ANH VIKdN.
At Ihe end of llii' Lower Kamparts. Just
Ihe moiilli of the
'rjinana, the river auain broadens out into flats. The banks here aiH-
of liorizonlally slralilii'il silt, often .'!b, 40, or even do feet above the
water.' I'"roiii the ri\er these flats extend in perfect uniformity on
h side 10 or b"! miles back to the hills: but iliev narrow fariher
eai
down, till about
airain cuts on its
miles below the mouth ol
I'-iiiana the stream
iirlit bank the hard schists of the liirch (reek fi
lion. Melowlhis, however, th(> silts coiilinue
• expo;
ill pi:
especially on the left bank. They are al.so said lo extend up the
Tanana for niaiiv miles, causin;:
islantlv sliiflinir i-haiinels like
those of the Yukon I'Mats, and reiulerinL; stejiniboatin;;' diflicult. Lieii-
leiiant Allen - notes that below the Toelat l{ivor the Taiuma becomes
vcrv wide and si iiiriiish, with sometimes
■iCNeral eliannels.
Th
ind(
the manner in which il enters the Yukon, the various bran.'li-
in^s havinir the asjiect of a delta.
Aliciut till' 1st .if Si'|il..nilHi-
■ Ht'pfU't nf all Ex^H-dition to tin* t'tipi)rr, Tauuiiu. aiiil Kcyukuk Kivrrs. Suttutc IJuc. l-'.">, 1.SH7,
P.M.
^»^
TIIK VIKOX t^II.TS.
2' 17
About .ir) miles liclow the 'I'aiiaiia, on llic left siilc of the Viiknii,
rise i)('i'i)('niliiMilar Icvcl-ldijpcil hlutl's aboiii l.'iii IVi'i in liriirlit. 'riic
inalcrial in tlicsc h! nil's is niostly cxli'cinfly line sill, irrciMiisli-irfay In
color, I'oi'niinij; when wcl a tine, sticky clay, ami sliowiimscarccly .iny
traces of stralifical ion. Al inlei'\ als in Ihis deposit ,iie thick IkmIs of
vi'^etahle matiM'ial, containiiiir wood in all sta>,'es of cliaiiire. from
])lial)le sticks to hrit lie Ill-own liiriiite. Tliesi' beds vary in thickness
and also in the nature of ilieir material: usually, howcM'i', they con-
lain trees, sonieof coiisideralile size. .\l the hejiinninudrilie exposuie,
ami for some distance farther on, one of the heaxiest beds of woody
inatiM'ial is from (i to iio feel below the toj) of the blulf anil is about 4
feet in thickness, while diri'cl ly above it lie mixed L:r;i\ els and sill,
with occasional sli<d<sand lous. In this deposit, about li feci below
the surface, part of t li(> skeleton of a mammoih was founcl, and 1 usks
and other bones of this and other mammals are so commonly found
here that, as has been said, the locality is known amonu the nunersas
the 'Mioueyard," altlion,u:li it is \)\\\ down on li.cniapsas ihe Pali-
sades. \ tooth pl(d<ed u[i hi'i'c was identiliedby .Mr. 1". .\. I.ucas. of
the National .Museum, as beloiiLiini; to tin ■^uecics F.li fihns jirlinifii-
iiiiis. All through the thick sill wei-c f mud abnndani specimens of
the laml shell SiicfiiK <i cliri/nin West., w hicli is. accoi-dini;- to I )r. I ),ill,
still llviuu: in the rej;-ion.
About a mile below Ihe upp(>r end of these blulTs the sills and
lipnilc beds are dls|)laced by a sti'Cp fault, lia\ Ini;' a throwol al)onl
•"ill feet, and by this the up])er bed of the I'alisades connlomeiales is
bi'ouirht u|) below ttie silts. The contaci of the coni;loniei-alcs w ilh
the sill has a sliirhl inclinat ion downsi rcan'. showinu' .i scarcely per-
ceptible liltin.n'. (See \'\. WXIW)
These blull'sare beiiii;' conliliually nndei-cul by the i-|\ei\ and yet
Ihe clay is so lirm that the ii|(i)ci' ]iart of t'le bank often stands out
as a ])i'o,joctiii,u; slndf when the lower pa'", has been carried away.
When Ihis lop part linally falls, theiefore, it does so In i^reat masses,
and scMuetiines sinks ,nia<lually, wilh very lilll(> breakin;,', and lodui's
al the fool of the blulV, where lh(> trees which 11 bears still continue
growinir. Al Ihe upiierend of the sill exixisures a lai'irc iiuiss, con-
taiiiin.n' ])art of the iipi)eiiM(Ht l-fool bed of lljfiille above referred to,
has sunk down in Ihis manner. The lijjnite in the fallen portion has
taken fire ami lU'arly burm'd out, altlimiirh in plai'cs it is still smok-
infj ar.d hot. TIk' ti'aasformalions ellVcted by this bui'ning in the
suri'oundin,u' materials iire curious and inter' si iiifr. lu llu' unb\irnl
lliinite are layei's rich in boj;' iron ore, which (Ui burninj;' is fused Into
a sort, of impure pi,u\ Other portions of the (day luue been fliseil
into vesicular slaj;', resemblinu' lava, while a little f; ther away from
llio burnt seam bright-ied bri(dv has been formed, which is exactly
identical in appearance witli artiliciar brh'k. ( )t her port ions of the
clav a.ssume varhnis brii;l;t color-; m dilTerent stages of the baking
m
'rw
I
i
•JdS (iKOI.OGV Ol" THE YUKON GOLD DISTKK T, ALASKA.
pi-ocfss i^rccii, (iiiilini'. yellow, and ii'd— aiid llii'st- baked clays often
sliow heaiitil'iil leal' iiiii)i('ssioiis when l)r(dieii open, wlileii can not
he diseeiiied 'n tile unliiniil slale.
On llie lace of the lilull' tVoMi wlileli ilic mass coMlainln^ the buni-
inn' liyiiile seam lias fallen the same seam is exposed 1(10 feel or so
lii^dier up. liiil liere it lia> not been on life. In a search for the reason
whv the liu'iiile in tlie fallen mass should have caiijrht lire, while that,
remaiiiinu- in t lie blulV escapeil. Ihe only iinporlant point ofdilTerenco
whicl nld be discerned is Ihal the fallen i)iirl of the s* .im is covered
1»V waler every year, while that in tlii' bliiH' is (piile out of reach of the
river. In spite of the yciirlv inundation, the llres have been bnrniiifi;
for a very loiii;- period, as li'arned from the iiali\i's and miners, and
it seems possible thai the water may have been the actual cause of
tln^ combustion. The iirocess may depend ipoii cliemical action
belwcen wat.iand some of the components of the silt or liirnile be<ls.
A familiar process of this kin<l is the alleralion of lime to calcium
hydrate by I he addit ion of water; the heal dexeloped is siillicionl to
sei surronnditifi' objects on lii'e. so thai to load •■ shij) with lime i.s
especially daii,t;'erous.
In till' liear Ki\cr, on llie Mackenzie beds, biirninfi; li.iriiite seams
were noticed a cenlni'y afi:o by Sir Alexander .Mackenzie, and tlioy
are .still biirnint;, as noticed by Mr. McConnell.'
.\Hil\'K TWIN MOINTAIN.
'i'lie silt deposits at the I'alisailes are comparali\ely narrow and
seem to lie ill a widenini;' of the old Vukoii N'ulley. They exleiid for
II' or I.") miles, and are llieii mainly replaced by .solid rock; at inler-
\als, lioweNcr, are still exposed banks of .t;;ravel, sand, ami .«ilt .")(i or
ilii feet lii^h. which rest uiiconfori ably upon the n|)liiriied coniflom-
erales of the Keuai series. Just below the mouih of Itie Soonkakat
there are exiio.sed on both sides of the river blulfs of evenly and hori-
zontally stralilieil sill, probably l.")ti feet in heijrht. In the lilllo
(le]iressions on the surface beds of jieat are forminji;, often sexeral
fe 't ill thickness, and the river, ciitlinf; the banks, exposes sections
of this deposit, showinji it to be oi" very much the same character
as llie beds of lifiiiitic nii'terial observed in the silts of the I'alisailes
and at other places, 'i'liese bliilTs soon diminish in lieii^ht and brconio
iiniforialy s' or 10 feet abo\e the water. The river broadens out and
the hills vecei'u , ;;i\ inj; jtlace to broad Hats, whose exact extent eoiilil
not well be made out. These Hats extend for about .!.") miles, ternii-
iialini; Jiisl iibove the month of the K'oyiikiik, where the\ are suc-
ceeded by hills and bold, rocky bliill's which are made up, in part at
least, of the folded Nnlato (.Miocene) beds.
'Ann. Ki'iit. Ui'ol. Nat. Hi«t. Survi-y I'liuaiUi, lf«»t-«l, Vol., IV. p. llfU.
m
BPURB]
THE YUKON 8ILTS.
209
EELOW THK KOYUKrK.
Bolow tlio Koyukuk tliorc occur narrow local flats on l)otli sides ot
the river, but almost ah\ays on Ihi' concave? side of Ilic ciiincs. 'I'lic
banks are oi'dinarily not over 1-2 feet above the river, and iheir lojjs
are covered witli a fresh layer of silt, which bejirs little ve};;etatiou
except rapidly-growinj;-, bright -green oquisetunis, whiili have evi-
dently all si)rung up within a few weeks or months. Si'ctions often
show n'peated layers of jxat .Jternating with tlie silt, the sueeessivo
accumulations of vegetation whu li were afterwards eovei'ed up by
flood deposits ; and in some layers tlio trunks of trees which have
taken root have been partly covered by silt, while their upp -r jiarts
still stand erect above the surface. In other cases the dead trees
have been b'oken oil' at the surface, while 2 or 3 feet of the stump
renuiius l)i:i'ie<l in tlie silt. Some of these erect stumps were noted
4 feet below the surface?. Shortly below Andreafski the Hats of the
Yukon delta begin. These are composed of silts like those already
described. The banks are low and treeless and are strewn with
driftwood, showing that they have been recently inundated.
The silt deposits .just desci-ibed between the Koyukuk and tho sea
have the same characteristics as the flood deposits in the Y ukon rials.
They are built up, by annual depositions of silt from the muddy,
flooded river, on a substratum of sand and gravels accumulated by
the water in its lower stages, uumy circumstances, such as the par-
tially buried trees and the fresh silt covering the tops of the banks,
showing that their fornuitiou is still going on. This is true, however,
only of those deposits whose lops are but a short distance above the
river-level. At an altituvie of l'O or :iO feet the flats along the Yukon
>re covei-ed with thick moss and are free from evidences of recent
inundation. At various points, moreover, beds of silt having the
- me appearance as those now being formed by the river have an
>ilL tude several hundred teet or more above the present stream, and
p. sometimes as much as 200 or 300 feet in thickness.
These eh^vated silts are evidently of greater ag! than those Ij'ing
only a few feet above the river, but there ir a grad'ial transition from
he higliest to the lowest, showing ti-at in the Yukon N'alley nearly
the same sediments have beendeposite*! during i. i)eriod in which the
river has cut down its bee' consid<u-ably. I'. Is to be remembered,
however, that even the most recent of these silts ai'e formeii under
conditions different from those usually afforded l)y rivers, since they
are built up by deposition from waters which are sjiread out in time
of flood and which have- comparatively little inoxi'inent : so that the
conditions are rather those of a lake than of a rapiil river. It has
previously been suggested that, the higher silts of the Yukon Flats
were probably deposited in tlie bottom of a shallow lake, while the
more recent ones w(>re forimvl under lacustrine eomlitions in time of
18 UKOL. I'T 3 11
210
C.KOI.OliV or THE VIKhN (lOl,;. .USTlilCT. Al-ASKA.
(looil, aiiil lilt' slcp t'l'diii line to llic ollifrcinidit ion is vci'V sliirlil. 'i'lio
< li'\;ilcil lii'ds of pure silt ill .MyiKiok ('roclc. Ilic I'lilisadcs, hciow tlit>
Siioiikakat. and al ntlicr places aloiiir (lif rixci', scciii 1<i sli()\v thai tlicy
well' roi'inrd at a piTiud wlicii lai'iistriiic conditions prevailed for a
eoinparal i\ ely loti^ linu'; I'oi' they are ol'ten many I'eet thick, witlKMif
any iayeis of \eij;etal)le matter or of coarse detritns, and so can not
Well have been I'oriued in Iheshoi't space of time allowed by a sprinjj
Hood. 'I'lic i,'real tliicl.'.,>ss of these deposits is also airainst the idea
of river deposit i ,ri.
SI I. IS ItiriWKKN I.AKK 1
AN AM) Tin-: I'lVK KIN(ii:H HAl'lDS.
On the Lewes liixcr. above the junction with the Teslin, is a series
of lonu'. narrow lakes. (See IM. XXWII.) Four of these, iakes
I'iK l:.v \*ii\\ at ilif hfuil i-i' Ljikf I.iniit'niuii. Inukin^r w.-st. slmwiim tin- hiu'lifi' i k .iit
T(-iTR<*i'. its t.)i> 'MitUiu'il l»y Mi;(iw, . I Ml tilt' saiiu' 1>'V.-1 us this is tin- U'^jiiuiiii^r oi a ltroa<i valli-y
"I c'.iiii|ianitivi>ly slij;lit simdiciit, wliicli fcadn's lnuk sniui. .lisf.-iini. Irum tln' lak.' rivnii tlio
It'Vi'l nf tin- riM'k-ftit torrat'c tlir wjitiTs pliiii^f smlcU'iily dnwiiwanl. aiul liave <'arvi'il u ^inall
caiiyi'ii
Liiiileiiian, IJeiitM'tt, Ta^iisli, and Marsh aic closely coniu'cled and
have nearly the same le\'el. Lake Lebarjre is .somewhat o\'er -lO
miles lolly, and is separated from the rest by (id or 7iMiiiles of lajiiil
river. Li is llie lowest in (he series, beinir some .'in miles aboxc I ho
iiiiinlh of the 'reslin. All these lakes occupy iiortions of the old,
tleeply eroded river valley.s of the \'iikoii and its tributaries, wlieio
«.|
il
i9
I
USGtOLOGICAL SURVEY
EIGHTEENTH ANNUAL PCPORT PART i!i PL.VXXVIl
FairweaUier ^mJ*t litu ,a
lev! apt'*v .-%
01 njNE MM' 01" Till-; ri»i»i;H yikon and \i(1m'I"iai)AI'ti:i,> i'hom co.vst sruvi:^ ciiahi' t
Siiili- III null--.
--=»L-._ . te^
Arrn <M'cn|iit'(l Ipv lliis Mii|i is ilm^vri liy diisliocl lines mi I'l XXXII ' (li'iii'inl M;i|i cil' Aliiskii
«
Bl'CKHl
TIIK YUKON SII.TS.
211
1]i('s«> viilloys liavc hcoii ohsti'iicti'd (ir (li'I'dniicil so as to (Imti up the
(li'iiiiiajfc. 'I'Ik' liver, wliicli (pccupics its did \,illi'.\' Itdnw llir lakes
and between Lake I,eliari;'e and Lake Maisli. is at ihcsimiI mi \ lapid
aM<l is <'n1t in,u: down ils eliaiine! sollial llie lakes ar<' l)ein.u' ;;i-ai|iially
drained; and il' i)resent eondil ions <'on! inne lliey will have eiit irely
disap()eaii nithili a eoiuparatively slini-t peiiud of iieolniilial l iiiie.
'I'liat this proeoss of draiiiini; has }i;oiie (;iv is shown l)\ le\il \rv-
raci'H and deposits of linely sti'atilied silt above the picseni level of
the lakes ami in places alonu' the hanks of the down-enti inn ri\ei-.
The leri'aeos were lii'sf noticed on Lake l.indeiiian. on the slimes
of which thei'e are t wo \ery <listiiicl lieiiclies. One is alionl "lo I'eet
above the lake, and is composed of saml ami ^ia\il which, ulieu
nndei'ciil by the water, form conspicnonsyellow exposnies. The sec-
ond terrace is eiinsiderably higher and runs back in some places a
loiiy; distance from the shores, to a line where the nnifoi-Mi npward
slope of the mountains bei;ins. ( )n this njiper terrace arc bare,
I'oiinded rock surfaces which ar(> cut by small valleys of consideiable
depth. (See li;r. 1-.) Tin' lower tcri'ace, therebire, seems to In n-
strnetional. and to have been bnilt up in ipiiet walci's. while the
ll[)[)er ont' has the a|)pearanee of ha\ inu' bi'cu carved out of the rock
l)y a body of wali'r capable of sweepinu' awa\ 'he rock frairnieiiK as
fast as tlu'y were worn from the hills.
On Lake Tajiish and Lake Marsh there a I'c blnfVs of tine. lioMioi;e-
noous silt, horizontally St rat ilied. J(i or :!ii feet in hci.uiit. Thai pari of
the Lewes River which connects Lake Marsh with Lake l.eliari;e is
known by the miners as Si.xlyinile IJivei', it beinii' appro\iiiiaiel\- of
this lenuth. On the upper part of this river the sill bliilVs are :lii or
40 feel hiiili. and they gradually }j;row liifjlier farther (lown the si ream.
About halfway bet ween f.ake >birsh and Lake Lebaruc I he ri\er \ alley
has been dammed by a (low of basalt. throUi;li wlii<'h the sireaiii has
cut a mirrow caiivon where ihe water Hows very swiftly, .lust below
the canyon are the White Horse Hapids, which are <luetotlie saiiio
cau.se as is liie canyon, the water beiny here also eoiiline(l by sleep
l)asalt walls. At the White Horse Kapiils Ihe basalt is overlain by
horizontally stratilied silts like those described abovt'. I'rom the
White Ilor.so Hai)i<ls to below thcTahkeena River(whieli lies between
tlio rapids and Lake Lebarac) there are no rock exposures, but Ihe
river flows lliroiifih sleep banks of sill, which arow coni iuually and
gradually in hi'i.nht, till at the nioulh of the Tahkeena River their
lieiglit ^Viis estimaleil at lod feel, 'i'he material shown in these cxjio-
sures is chiefly line silt, sometimes with j;ra\('lly layers, and u-ciierally
exhibit iiiji' even, horizontal stratilication, but often so honioireiicous
tliat no tra<'e of stratification could be delected in thickiu'sses of many
feet. The river is continually undercuttin.u- the banks, so thai every-
where columns of dust are .seen asceudin;; like smoke where a iiortion
of the bank topples into the stream. In this way the river 1 ones
B:
21'_* OKOI.dGY OF THK YUKON (iol.U DISTRICT, ALASKA.
vory iniidily, and is si ill iiiorc liitilily cliiirjicd willi scdiriieiil from tlio
diiiy w.ilcis ,i(' llic 'r.ililccciiii. Ill l.aivc l.t'ltar^^c, liowovor, this iiiiul
sclliL'S. solliat tlie wilcrs of llic I.cwi':;, as llicy How fnun tin- fool of
ilio lake, arc coniijaral i\ dy di'ar and of a frrccnisli color.
Tlio scdinicnis now foi'ininj;- in Ilic holloni of J-akc Lcbargo must
tlicn^fon- lie firowini; rapidly, and iiiiist consisi iif line, liorizonlally
stratilicd sills, cxacily like llic dcposils from wliicli tliey arc immc-
<liaicly derived, and wliicli are now exposed along llic hanks of llio
river. If in the p'olojrjcjil fiiinre Lake Leharp' is drained, as it must
he if tlioiiresent rapid downeiilliiifrof the river continues, the material
now aceiiiiiulaliiiu "ill he exiiosed aloiiir the hanks of the new stream
Fin. 13.— Bowklor-cliiy, silt^ , .'mil ^.Tiivols on tlio Lewos just bulow tho TetJlin i HootnliiHiua).
and will have the same appearance as the older deposits. Tho ovi-
doiicc i.i their later aj;e, however, will he found in their slifjht olova-
lion iibovo the stream as compared with the greater licipht of the
older .accumulations. This would h(> analo,u;ons to" the eases already
described alongthe Yukon between Circle City and the sea, and notice-
ably in the Flats bet ween Circle Cily and Fort Hamlin, where ,sedi-
iiionts of nearly uniform appearance are found at slijthtly dift'erent
elevations; and of th(>se the hitrhei' ones were jmibably laid down in
old lakes of considerable duration, while the lower ones were deposited
later, at times of Hood or temporary damiiiinff of the river.
Lake Marsh, wliicli lies above Lake Lebarjie, is called by the miners
I
■*'
THK YUKON SILTS.
213
]\Iii(l I.iikc, (111 iH'J'oinil of its slialliiw, iiimMy lidtidiii .iiin slnn-i's. Ili'fo
iifraiii I lit' scdiiiiciils arc exactly like tliosc ot' t he liiirlicr lil nil's, ami ilio
process of tlu'ir formation is like lliat at Lake Leharue. in the hul-
toiii of tiic lake tlic silt, aeciitiiiilatious must Ix^ very tliieU.
The exposures of sill in lilull's cease, so far as uhsei's I'll, at the
<>xtremc u[)|)cri'ncl of Lake Lcliar>fe. The shores of this lakt* wliero
exaiiiincil were lai'^cly of haie I'ock. At the lower end of the lake
the Lowes River at first flows through hanks of gravel ami sand .ii)
feel or less in heiijht. Below these u'ravels there is (iricii exposi'd clay
containinj,' pclililes and snlianirular howlders, Ihe deiiosii beinii' evi-
dently of ji'hieial ori;jrin and ha\iiijj: ordinarily the asjieci ol ,i trim
till, llioiifrh often showing signs of sir 'irication. Near the Jnnelinn
of Iho Lewes with the Tcslin this glacial dei)osit, capped Ky gravels
and intcrbcd<led silts, forms stcc)) scai'jis imi feet in heiglil. (See
lig. Vi). Below the Tcslin Ihc top of the howlder-clay hcconics gradu-
ally lower, and the banks are made up more and more of si rati tied
silts and gravel, till near Iho junction of the I>ig Salmon iJixcr they
aro often entirely of liuoly stralilied matoi'ial, and are still as much
as 1011 feet ill hoight. The silts conlinne to he expose(l, allernating
Fkj. M.— Diaj^runi sliowiiiK folding in silt liluffs ou the Iji'Wuh ahovt! Miles C'anyou.
with frequent rock oulorops, nearly to tlic Five Finger Jiapi<ls. In
the neigliborhood of tlu' rapids Ihey practically stop, and hetwccn
here and Circle t'ity, a distance of al)oiit -t.")0 miles, the Lowes and the
Yukon flow past banks of bai'c roek, except where the stream has
I'ornu'd local deposits of sand aad gravels, which it has afterwards cut
through.
The silts between Five Finger Rapids and Lake Lindenuin. are
ol'ten seen to be veiy slightly but distinctly i)licat(.'d in |)laces. (See
lig. 14.) This folding is ([uite recent, for the little syncliiu's in tho
surface have been adopted as channels for Ihe drainage walei', and so
have sometimes dev(doped into gullies. Along the river between Lake
Marsh and Lake Lebargc, and between Lake Lcbarge and the Five
Finger Rajiids, there is often a layer of river pebbles and sand, hori-
zontally stratified, topping th(> silt beds and I'csting nnconforinably
on them where they have been plicated. This layer is never more
than a few feet thick, and is often entirely wanting. On top of the
river gravels, or, where these are wanting, ou lop of tho silts, is e\ cry-
vvliere seen a thin layer of white, gritty volcanic ash, which ordinarily
conforms to all the little irregularities in the sui'face, and which, there-
fore, has the appearance of having been deposited a comparatively
i* 'I
:.'14 (;i;i>i.(i(iv ov iiik vi'kon (ioi.u Disruicr, Alaska.
sIkhi tiiiii'Myn. '11 lis Nulciiiiii'jisli is widely disl li lint ci I nvcr I Ills por-
lldliiir Aliisi-.a, iiiiil liiis Imm'Ii (Ic'sciilMMl hy nciiily all I ia\ I'lcrs who
liavi' |ia->c.(l iliroiiy;!! Ilils n'yimi. Aloiii; this part i>f the river llii>
lavfc is iH'MT iiKne than a few iiiclws tiiick.aml is inn liatcly nvi'v-
laiii li\ si'vcial iiichi's (if \ cuctaliii' Inain, "liii'li rcifiiis the iiMnicilialc
sni lai'i'.
Till' stca'lv increase in elevation of the lowest liroail sill terrace"
from the lakes to the I'alikeena Kixfr indicates that tliesnrfa< f
this lowest terrace is \(>ry nearly liori/onlal, mo that the rixcr. in :-.il-
tiiijidown Ihrouiili it. Ilows hetwi'en hi^jhcr and hiy:h('r liaiiks as it,
reaches siiceessi\ely lower points. It is prolialile, Ihcr'cfore, that this
deposit was laid down in still water or in a scaiecly |)erceptihle enr-
reiit.and the iiatiircof the sediiiieiils. which are like lhos(> now I'orniinu:
in Lake .Marsh and in other places under lacnst riri iidit ions, points
to the same conclnsion. So far as ohservci!, howc.-er, t he cont innity
I't' the silt deposits appears to he broken at the upper end of Lake
Leliar^e. At the lower einl of Lake Lehai'f::*' arc low lianks of howl-
der-clay and j^ravul: licdow tlie month of the Teslin tlie liowlder-
' lay liecoincs ea|ipcd by an incrcasinir thickiu'ssof silt and gravel,
md the filaeial material appears to pa.ss laterally into stratilied
dcfiosits. 'l"he hoifjht of the banks also increases soniew hat, althoiiiih
not so markedly as on Si.xlymile River between Lake .Marsh and
Lake Lcbarj;e; however, between the niontii of I, itt le Salmon Kivcr
ami l'"ivc Kin^jer i{apids the luterbedilcd sill and line gravels are
sometimes e.\|)oseil in porpendieiilar blntl's lot) feet in heiitht or more.
These deposits often bear evidence of the e.vistence fo'- lonj; periods
of nnifoi'Mi con<litions, bnt tin; narrowinfi valley and the frci|neiit
f;iavels show that the body of water in which these sediments were
laid down was n;irr<iwer than that which e.\istc<l above I>ake
lA'barjic, and had probably in places .some ciirr.'iii.
Aceordinn' to aneroid dctcrnunat ions maile by Dr. Dawson's i)arly,
the surface of Lake Liiidcrman is 7l) feet hi;;hei' than that of Lake
Lebargc, the elevation of the former beiiiii' lMTh feet aiul of the latter
:.',UHi feel above the sea. The main gravel ami silt lorriice (ni Lake
Limleman was estimated by the I'liited States (ieologieal Survey
(larty as being ."iD feet above the lake, which would give it an altitinle
of J.JJii feet, .lust above Lake Lebarge the broad silt plain through
which the river cuts was est imatetl as being more than l.'iO feet above
the water, and is thcix^fore at an appro.ximate elevation of l',i'.5ii feet.
This elevation is :iit feet aliove that of the Lake Lindeinan terrace.
It must be rcmemtxM'eil. however, that the elevation of the lakes as
• Ictcrmim'd by the aneroid can be only ap[)ro.\imatc, and. moreover,
that our own estimates of the height of the blntl's at the various
lilacesare m'cessarily inaccnirate. Careful surveying might make the
<lilTcrcnce more or less, but it seems certain that the tui) of the lowest
silt deposit is nearly horizontal..
, 4
TIIK YUKON -1I,TS.
•ii;
AIpdXc this liiwcsl Icrracc there iire -.eeii III! nil llie lake,-, nil >i\i\--
lllile Kiv er, .lllil (III llie I, I'W es Well-ma llieil liellelies, « ji ji'li (ieelll'l||i
til a eiiiisitleialile lii'iuhl. |)i-. hawsiiir e^timaie^ tiie lilu:lie>i ii'f-
iace> nil Lake l,el(aii;e as lnii iVel alH(\e the laki', while I'mlessuf
Unssell- pills their heinlil at .'i"'!! or I'lim iVet. On the li.uer |iarl nf
Lake IJelinetl the liiylii'r terraees were e>t iliiati'il li\ the uiilei a>
lieilii;- li"i cir .'iiii I t'eet alii)\ c t he uater. < Hi Si\t \ mile Itiv er. Iiet weiMi
Lake ALirsh ami Lake Leliar;;e. t ln' two Itesl-marki'il terraces were
measiireil with an aiierniil liy Mr. Sehrailer ami t'oiiml to lie 17"p I'eet
and ^iiiii I'eet alidxc I he river. Tile il|i|ier one w as lii'>l iiiaike(|. (t|'
lllese sllee('ssi\ e terraces the liiwesl are in ;;eMeral the iiKJ-t regular.
uikI are iiiad)' up iil' silt, sanil, and ;ri':i\<'l. Thi' upper (iiie>. uhieh
were mil earel'iilly e\atnined, are imire irie^'iilar in dc>lail. and nl'teii
liaxc the ap[iearaiiee ul' lieinn- rnek-ellt. alt hciliudl elielimliered with
j,'ra\el and sand. On Lake r.ennett lieiiehes Juii oi- .'inn feet alnixe
the lake are s'rewii with lar};e ;;laeial Imw Iders <<{ ^'lanite. w hic'li li,i\ c
bi-eii hrciiijilit friim a jioinl soini' miles up the lake.
The oecui'i'L'licc of tcri-ai'cs or lienelies i^ liv im mean-- limiteil to I lie
v! iiiity of the lakes, for Ihey \verc> oliservecl all aloni; ihc ^ iikon
l{i\er lietweeii here and the sea. They liaxc iieeii miled al many
points in .Maska and llriiish (oliimhia liy(;. .M. Daw.son and K. (L
.Me( oiinell, and are foiind on islands in Ueiin^ Sea. 'i'hese terrai-es
will lie spoken of in more detail later in eonsiderim: I he movements
of the land, and il n I only lie staled here that the whole interior
plateau of Alaska and lirilish ('olumliia ajipears to lie distiiietly ter-
raeed up to a trreat hei.irht, wiiieli may he ap|iro.\iiiialely staled as
;!,lll)(l feel above the sea. Above this oeeasioiial terraces are fouiiil
up as liiiili as ."i,.!iio' feel. .\s pointed out by Dr. DawM.ii. Ilicso
hijiher terraces are disliiicl from Ihe abiiiidanl river terraces in that,
they do i;,it alwa.Ns follow the river valleys, bi.l skirt tile di\ icies
and appear far up on the liiiiiicst hills. They seem lo mark the
former shore-lines of a ifreat level body of wali'f wiiicdi Hooded the
whole counlry, and from Iheir |iresence in such places as the nioiin-
taiiioiis islands of jierinj;' Sea it is evident that lliev are marine.
From Ihc clearness wilh which they are ordinarily cnl, iiioreo\er. ji
is evidiMit that llicy were formeil at no very ancient ucoloyieal perioii.
For these reasons Dr. Dawson has coiisiilcred the leriaces, which
have been described, above the lakes on the I'pper ^■ukoll to be of
marine orij^in. Evidence found at other places shows that the sea
probably eiicroachefl lliiis far al least, and when il stood al tliisideva-
lion it must have formed shore-lines. The characler of the upper
lienches on tin' lakes, such as the bench described on Lake Limh'iiiaii
aljove the yravel terraces, favor.s the idea tif marine origin, for I hey
I Ann. Kept, (lecil. Nut. Hist. Sui-vi'y t'liiincla. IW ■•«. V.il 111. I'iiit 1. p iviji
-Xotps on till' siirfiu'i'K'i'iiloKy nf .\liiskii: Hull. (frol. S«<' Aiin'ricu. Vol 1 p, li;.
"G. JI. Uawsmi, Trans. Uuyiil Sue. L'iiu:iUii, WJU, Vul. VIII, Si'c. IV, [i. :!•>.
L'li;
(ii;i)|,(M;Y or TIIK YI'KoN (JOI.P DISTUICT, ALASKA.
;i|i|M'iir I" 111' ciiiNcil mil 111' ilii' licil-i-cick, ami siirli ii iiictlKMl of I'orina-
tliiii involves acli\c rfosiou anil iicIIm- ri'iimval <il' (jclfiliis, such as
woiilil !)<■ acconiplislicil l»y tin- waves ami emrenls of tlic soa liiit
wilh (liniciilly Ity the <|iiiel waters of a small lake. Dr. Dawson,
however, applies the idea of marine oriu'in to all the phenometm. and
eonsiilers all t lie lerraees as marking marine shore-lines, and I he silt
deposits as lai<l down in an arm of the .sen, which he proposes to call
^■|lkoll Inlet. I'revioiis to the piililieation of Dr. Dawson's paper
eoiitainin^: the aliove eoneliisions. Pi'of. I. ('. Uiissell' luul traveled
Ihroiitjh this ie;rioii and hail eoacliided that the sill deposits were
for I in a lake, whieh lie called Lake 'iiikon.
Tl haiaeteis of the sills aresiieli tlmt they must have oriiriimted,
if not in a lake, at least In a body of water where the conditions
were lacustrine. These characters are idcntii'al with I hose of the lake
deposits already dcscrihed farther down the Yukon. When it is con-
sidered that as far down as Circle t'ity the occurrence of the silts is
practically limited to the rejxion lietween the Five Finder liapi<ls and
Lake Lindeman, altlion;;h the terraces aecompaiiyin;: thcin in this
reuion continue down the Vukoii iiiiitc to the sea, and that the dis-
trict lo which they arc thus limited corresiHinds in a genei'al way to
the rei;ion of the [u'escnl lakes, it must he admitted that there seems
piod jfroiinds for Itelief in their lacustrine orij^iii. 'rh(> ahseiice of
inariiie fossils in the silts, as Dr. Dawson himself [loints oiit,^ is nef,'a-
tive evidciii-e a;;ainst consideriii},' I hem marine.
The assemhied facts wiiich have heen cited seem to ]ioint to an
explanation inlermediate lietween the dilTeriiij; views. The benches
or terraces all o\er the interior plateau of Alaska and Uritish Colum-
bia, frinjring' the mountains and the inountainoiis islands in the sea,
point to a <M)iiiparatively recent subinerj^eutx'. This snbinertrenco
was probably :J,iHK) feet below the present jjeneral level. The sea,
therefore, must have invaded the deep, narrow valley whicli the Yukon
ha<l jirevioiisly cut in the old plateau, and toward the head of this
valley must have stood fully as hii^h as the liij.;licst of the observed
terraces in the lake rcfrion.
To marine action at this period the upper nx-k-cut teri'aees, often
encumbi'red with ;rravel, may be assiffiied, their formation seeminy
to indicate active erosion and transportation fijreater than is ordi-
narily po.ssible in a small lake. When this upper part of the ancient
river valley cmcrjred from the waters of the ocean it was slifrhtly
depressed relatively to the lower [lart, so that the drainaf^e waters
spread out into hmg, irregular hikes, stretching over the old chan-
nels. Whetlier the de[)ressioii which gave rise to tlie lakes was
<lue to sliglitdeformation attendant on elevation or to other caii.ses
is not certain, but similar differential movement is now undoubtedly
> Notes 1111 till' surface tteolrifty of Alaska- Bull. Oi'^il. Sih:. Aiufrifu, Vol. I. p. Hi).
'Trttll^s. Koyal S.ji'. t.'uiiailft, Vol. VUI, Si-l-, IV. ji. -i;!.
'IIIK VUKDN SILI'S.
217
jjoiiif; (III ill Alaska. In lliis case llif cause ol' ilitViTfiilial iiiii\ I'liii'iil
or ri'lalivr (Icprt'ssiuii may liavc liccii, as sii;;y:f,'«ici| by I'lofcssor
]{iiss('ll,' the wcinlil ul' till' irri'al ccirdillcraii irlai'icr.
'I'll!' approxiinalc cniiicidi'iicc of llic iKirllnTii ImmmIci' oi' uhK'iatiiiii
ami lit' tlu! Hilt depoMilM in this rc^rlnn seems tn Cavnr iliis li\ iMiiliesis;
lull whatever may liave 1 ii tlie eaiise iil' its (iriiriii, it is eeriaiii lliat.
a liasiii was t'lirined aixl si ill i-xisls, ;iii<l the lake nr lakes v\ liieh ii-
]iie(l it i III me( I lately after the retreat of ilie sea may perhaps lia\ e siooil
at a level not jjreatly aliove that of the pfeseiit lakes. If it lie assiiiiieil
that the lower griivt'l teira iii Tiako Lindeiiiaii was the liist deposit
of the fresii-waler lakes and that the roek-eill terraces aliove are of
marine orijrin. then the lake may have stood oriirinally only |i"i feet
(ir less aliove the present level of Lakes liindemtiii, 'rairish, Meiiiiett.
and Marsh. t)n the bottom of this lake the levid silt deposit found
colli iniioiisly hotween Lake Lindeman and Lake Leliarye. hut liest
show 11 on Sixtymile River, may liave heeii laid down w Idle sandy e.nd
ri'a\'elly terraces were forinin}; hi{;lier up aloii}; the shores. The lake
seems to have been interrupted or to have jireatly shallowed at Lake
Ltd)ar{j<>. Here the silt, deposits are siiceeeded by rock shores, and at
the fool' of Lake Lebarf^e, where silts and <;ravels ha\ in;; the apju'ar-
aiK'e of laeustrine orijfin are aj^ain found, they are at a lower level,
iiidicatin^r a somewhat sepai-ate and deeper basin. IJelow Lake
Lebarf^e the silts frequently indicate lonj;-eoiitinued seilimeiitation in
([uiet waters, l)nt the iiiorainal material found aloiijr here has caused
irregularities in deposition and variation in the nature of the se(li-
ments, so that the charaeters of the deposits arc by no means coii.stant.
The narrowinj; of the old valley in this rejrion is likewise adverse to
uniformity of sedimentation. The lower body of water below Lake
Lebarj^t,', <ir the lower extension of the princi[)al lake, must therefore
have been narrow and in places like a slugi^nsh ri\ er, and must have
passed fjraduallj' into a swifter river above the Five Fin;rer liapids.
With the further elevation of the land above the sea, the rivers
became swifter and capable of carrying more water within a given
time. Hy virtue of the increased erosive power gained thereby they
also began to cut down their channels, and in this way tlie water of
the lakes was gradually drained, so that the narrow lake or lakes
below Lake Lebarge disappeared entirely, and the upiicr lake, which
Professor Rtis.sell has named Lake Yukon, siirunk to various small
connecting bodies of water, now known as Lakes Lindeman, Tagish,
Hennett, Marsh, and Lebarge. The stage when the increase in (do-
vation accelerated the movement of waters, so that narrow lakes
became transformed into broad rivers, is marked on Sixtymile Hiver
Ijetween Lake JIarsh and Lake Lebarge and on the Lewes below
Lake Lebarge by the layer of gravels which overlies the silts, and
was the lirst deposit of the young river. There are evidences that
H)|). rit., p. 14H,
Wl
■i
I
21S
(il'.dl.OGV or THE YUKON OOl.l) DISTRICT, ALASKA
clfNiitioii III' iIk ImimI is siill ill piu^'i-.'ss ;il tlic iircs.'iil time. The
livcis .-irc still I'iipid .-111(1 .ire ciittiiijr lowii I heir cliaimols, so tlicit tlie
(liaiiuifff iif tilt' lakes is still ^niiiu: "n, iiml i" emirse i>f time they will
shrink to still sinailer ilimeiisioiis, or vei\ likisly will Ix' entirely
drained, in whieh event tiie iiresent shore lines and tlie silts aeeiniiii-
latinj;' on the bottom of il>e lakes will he exposed aloiijc the banks of
the fntiii-e river in sill hluIVs timl terraces identical in a.ppeai'aiice
with Ihirse now roiind, and foriiiiiii;' a 'latiifal e(iiiliiniatioii of them.
Another faeior in' the (haiiiiiii,'' of the lakes was probably t i It in;;.
So uni'at an elevation (probably at h'asi ij.oiio iVct) was not witliollt
.some slight irre;;iilaril ies. Indeed, on the Lower \iikon and its trib-
utary st reams, it appears that the land is beinj;- ele\ ated more raj (idly
to the south than to 1 he north, so that the streams crowd over to their
northern briiks. If this dilferenl i.d tdevation extends to the rei,'iou
iif the I'liper ^'^lkon lakes (where time was not available for investi-
{ration), the drainage of the lakes innsl be accelerated thereby. .Moi'o-
over, if. as has lieen sn,u';.^ested, the depression of the ancient ri\er
\alleys. forniinir lake liasins lliroUi;hoiil this rejrion, was eaiisecl by a
sinkinir of Iheeirth's ci'iisl 1(\ the weitrht of the cordllleraii ulacier,
this same rcirion should now be f i:ainin,u: its former elevation, and in
doin;i' so the water aceiliniilated in llie depressions would itradiially
be dischartred. That there I;ave been local dist iirlianees diiriii!.': t he
proi'ess of elevat ion is show i; by t he slight (ilicat ion of tiic silt ImmIs
and liy the occasional faultiim'.
INTKUmi! I'l^AtKAl HIKJION (II" UUITISH COHMltlA.
I)r. (;. .M. Dawson has describe<l ' silts like those of the I'pper I.ewes
as havintr .i w ide distriliiiti.in over liritish Cohimhia, in many valleys
and lakes. ^Ml t liese occurrences Dr. Dawson orrelates under the
head of the " While silts," aiid, as in tlieca.se of tin- silts of the Lewes,
sniiiiorts the idea of their marine origin, suggesting that they were
lai<l doxMi III tiords ciiiinectiiig with the sea, their materials being
deri\ec| from the dt'bris of the retreating cordilleran glacier.
IM-;i,l,V IMVKK.
Dn ae<-oniii of its proximity to the Lewes, the I'elly Uiver may bo
especially iiientioned. Dr. |)a«soii has iioieij- along the I'elly below
Koss ]{i\cr silts like those on the l.i ..cs. ol'teii ."iii feel thick, ami rest-
ing upon liowlder-clay and gravel. These silt bliilTs arc cut out of
tlats. which soinetiiiM's stretch for coiisiilcralile distances awa. from
the li\ er.
' rnui-. Royal S. . Ciiimilii. I»!«l. V.jI. VIII. S».i' IV. p. It rt w.).
»Aun. Kt'iit. Uo< . Nut. Uist. Survuy i.>!!!id», l»r-B«,Vul. UI, I'liit 1. 1). l:>ih
THE YUKON SILTS.
219
1
TKSI.IN ItlVKK.
Oil till' Tosliii (IliM)t;iliiii|iiii) l{i\fi'. Dr. ('. W. Ila\c>' iKitccI ron-
tiniioiis Icvcl-loppi'il hhitl's, cciiisistiiiii iiiiislly iif sil',. willi laviis of
sariil which .•ire cit'tcii I'loss-hiMldcil. Ilii' wliolc lii'inir ciippod li>' a l»'il
of coai-se tiravcl in Icct m- iiicuc lliick, wliicli is shaipl.v cpaiati'il
from the I'liidcrlyiiit;' silt turiiiatiuii. The hliiiVs iin-rcasc in hciirlit
from inn ft'ct at F.akc Aliklcn to {."infect at llic nth of ihi>ii\ci-,
anil arc fi-ci|iiciitly cut inio a ininihci- of terraces.
KdWAK (I, AYS AM) i i i:olM>-l( I'. I'nliM .\Tli iNS.
rmlcr these heads Dr. NV. II. Dall ' has dcscrilied a series of clays,
with often interstratitied beds of ice. which occur at \arions points on
the .Maskaii coast, notably on Koi /.el, iic Sound ;ind the Kowak lii\er,
as described by I.ieiiteliailt (,'aiilwell. Alonii the shores of the .-.ea
and the banks of the river there are e.\i>osed in inan\- places dill's of
simIiI ice, V. hic'li sonu'tiiiies rise to a liciuht of l.Mi feci and are co\ereil
bv clays and da;k-c()lored earth, on the lop of whicli lioiirish trees
and moss. This ice tlierefoi-e plays the part of a rock forniation.
The clays also occur in ]ilaces where the ice is absent, and on the
Ko -ak HiYcr forii; in one jilacc a bliilV tliree-i|iiarleis of a mile lonsj;
and I. "in feel hiirh. ( »n Kol/.cbne Sonml. a' Klcphant I'oint. the beds
of blue clay contain nniiieroiis bones of ricistoccnc man. nulls, such as
ti.;- eh^pliant. h.or.se. and bnlValo. and in the Kowak I'lays are also
nian\ niamnuilh Insks. Dr. Dall describes some of the clays at Kle-
pha.n I'oint as containing;- iiiiich vojiolable matter minirleil with the
clay or foriniu.ir distinct layers in it, and in one laver of spliau'iimii or
boii moss fresli-walcr shells of the eem.ra I'isidiiim. N'ahata, dc. were
found. These ice and clay deposits are considered by Dr. Dall as
li:i\iii;' lieeii foi'incil in vast shallow lakes, and are referred >oniewhat
ilollbtMllIx to the rieistocelle.'
I iil{|{Kl,AM')N.
Tn all the localities which have been descvibed are deposits of silt
havini.' similar <'haraclers. showing' deposiiioii in liod'-s of still and
,.i'te-i iindonlitedly shallow waler. These sills ofle ; contain the
reii..(iiis of the mammolli and olher I'lcisloceiic in ^unals and land
and fresh-water shells of living species. Wood am. \ci:eiable inali 'f
are also abiindanl in pl.ices. In most cases it seems ceilain that the
bodies of waler in which the deposits were formed were fresh-water
lakes. The silts of the rjipcr \ ukon and the siirroniidiiii; re-ion
ha\e been supposed by Dr. Dawson to be deposits in iiiai'inecsinarics;
I Kxpriliti.iii thl-otn-h IliM Yilkiili ilistfirl: Nut. i "■">;. Man. V.,1 IY.|. In'i
'' Bull V. s. ii....l Siirvry No. »4, Cori-olatloii l'niiur«-N.'."Oiu-, |j. am.'t -fii
■>0\). tit.. 11. :;iiii; al:<i) PI. III.
ill
■■(3
5
' '■!
>1
220 (JEOI.OGY OK THK YUKON GOLD DISTRICT, ALASKA.
but iit i)ios<'iit tlicrc iiri' iiniiu'roiis lakes in this foimtry, and the
raised iK-aciios aloii^' tlio coast and the rapid down-cutting of tiie
i-ivcrs in tlic iiitciior slmw liiat formerly those lakes must have been
more extensive, so that part, at least, of the silts must be of lacustrine
origin.
Considering tlie problem of correlation in the light of dynamic dis-
turbances, we lind that most of tlie silts wlien carefully examined
sho\ve\idenees of slight movement. On the hikesof the I'pper "^'ukou
tlie silts are in iilac<'s slightly but distinctly plicated, so that the later
river gravels rest on them \\ii!> slight local unconformities; in the
Palisades the silts have been displaced by a fault of 5U feet, while on
the Lower Vukou evidence of tilting is sometimes found in the incli-
nation of the surface of a silt deposit which must originally have been
horiz(jn1al. In no i)lace, however, have these deposits met with any
important disturbance.
A(iK OF THE YUKON SILTS.
The silts on the Lewes and Felly rivers rest upon bowlder-clay,
showing that they were deposited in places left by the retreat of the
glacier after its maximum extension. On the other hand, abov(> the
silts comes a layer of river gravels which tnarks the ])oin( where
tlie elevation which first caused the retreat of the sea Ijecame sutli-
cient toconvei't standing or sluggishly moving water into rivers. The
lakes of the Lower Yukon were also formed sabse(juent tothe retreat
of the sea, and were also draine(l in con.sequence of the increasing
elevation. It may be said in general, therefore, that the accumula-
tion of the silts began in shalhtw lakes and sluggish rivers on the
emergence of the laiul from the sea after t ,ie n: iximu n extension of
the cordilleran glacier, and has continued on a progressively smaller
scale u|» to the present tlay, since such sediments are now in |)rocc.ss
of formation in lakes like those on tlie Lewes, in sluggish parts of the
Vnkon and lis tributary streams, and on the (lood-plains of these
rivers. The gradually lessening amount of accumulations is due to
the increased elevation of the land and the consequent in<.'reased
carrying i)ower of th(> rivers, whereby the silting-up of the river beds
is prevented and the channels ai'e cut down so as to drain the water
fiom the old 'akcs. In the L'pi)er Yukon region tlio silts seem to have
been largely derived from material ground out of the rocks by glacial
action, and this material has doubtless contributed very largely to the
sediments of all the lak<'s into which waters rising in this glaciated
region empty,
t'oneerning the origin of these lake basins, it seems likely that
slight, dill'erential movements in the earth's crust were the most com-
mon cause. The elevation of the whole peninsula of Alaska for .'(,000
feet or more can hardly have taken pla<'(> without occasional irregu-
larities, the hitesl evidence of which are the slight folding, faulting,
11
H'rim.i
THE AXOIEXT GRAVELS.
221
jukI tilliiiirof tlio sills. Very sli.'iht local diffoi-oiioos wmild convert
portions ol' the okl river \allcys into lakes similar to tliosc now exist-
insi in the I'pper Yukon region, and in such lakes most of tiie silt
deposits seem to liave f'ornieil. 'i"he broad Itasin of the Yukon Flats,
however, can hardlj' \h\ considered as havinj; formed jiari of ilie ]h(>-
Gliieial valley oriln^ Yukon, since it. stretciies out abruptlx from the
junction with tliis vall(>y to a jrreat width. It is [lossible, therefore,
that this is an oro<;cnic depression of considerable ay:e.
Other hypotheses have been made to accoiint f(U-1he orijrin of t ae
Upper Vukon hikes whicli furlhei' study may sliow to be in i)art or
wholly correct. T)r. G. M. Dawson' snjj;g:ests that "the lakes of this
reiiion now (tecupy the place of the last loii<^ues of the fireat jrlaciei-,
wliich in the end disappeared so rapidly that their beds had not time
to become filled with detritus." Tlie same view was held fo: Lake
Ahklen by Dr. t'. W. Hayes,- who consiih-red that ''the present lake
basin was doubtless occupied by a lobe of the retreatinu: i^lacier, \\ liieli
prevented the silting-up of the portion of the valley so occupied. On
the withdrawal of the fjlaeier at the close of tlie stationary period the
lake was leftinuch as it. appears .it jiresent, only somewhat larui'r, its
wat(>rs beinii' held by the dam of silt which had been laid down in f.ont
of the ice." Prof. I. C. IlusricU ' sugfiests as an e.xiilanation foi- the
origin of the body of wattnMo which he gave the name of Lake Yukon,
that the river valley must have been obstructed and dammed iu some
way, possibly by the large lava-flow at the mouth of the Pelly, or by
morainal material deposited along the nortlnjrn der of the cordil-
leraii glacier. Profe.Sior liussell, liowever, holds an .si ill more prob-
able the hypoliiesis that "the weight of ice forming the tfnat
cordilleran glacier was sufHcient to depress the ear.h"s crust i the
manner suggested by students of glaeiatioii in other regions. As the
!<•(> retreated the dejiression thus originated was occupied by a lak. ,
wliich was slowlv drained as the land regained its former elevation."
THE ANCIENT GRAVELS.
ANCIENT Kl)LU-;U (iUAVELS.
The silts of the Upper Lewes in the vicinity of the lakes a.e over-
lain by a few feet of river gravels, as already described, and Dr.
liayesMuis noted a similar deposit on the Teslin River. All along
till' Yukon Hiver aic terraci's at various heights, and on these
are rolled gravels which aii' said often to yield gold in small quan-
tities. The successively higher terraces spread o\cr broader and
broader areas, so that it is ju'obable that the distribution of these
I Ann. Uept. Ooul. ITat. Hist. Survey r-anailn, Vol. Ill, Part I. IHHT-**. p. IKB.
'HxiiiTlitiim tliiMiiL'li tlio Yiiljon DNtri.-t: Nat. (t.-.m Miiit.Vnl. IV, ji. ."nl.
'Nnti's..!! ilii'Mirf.icvgeolntsy "1 Aliwka. Bull. OudI.Soc. AiiiiTl™. Vol. I.p. ll.>.
<0|i. cit., p. l.")il.
6i ■;'■
k
m
■!3
222 ni-oi.<if;v or thk yckon gold distkk t, alaska.
;,frii\('ls is MTV cxlciisivi'. On I'Vn'lyiiiili' (reck trivivols iirc fdiiiid
(•(ivcriii;; llw hroiiil. sliallnw Ti'itiaiy vallcxs, in tlic huitoiii ol' wiiicli
the lali'i' vaiii'vs lia\i' Ih-Va ciii. so Iliat in llii' irnlclics whicli head in
the dill \allcy a fonsidiTalilc ainunnl of liravcl is dciMxcd t'fiini llicwo
aii<'i«'nl sources. (Jrax.'ls alsn uccuron Ilic dividos liciwi'cn xallcvsot'
(•onsideraldc de|iili. sncli astliat Ix'twceu Cliiokcn ("reck and Franklin
(Jalcii on Furl yniili' (rock, on Myndok Creek {jjravcls contaiiiMig
watei'wiH'n |)elil)l('s of a \aricty nl' I'ocks, especially the (|uar1zilii!
scliisis (if the r.iicli (reek series, wliicli are nut IouimI in plact* in tlio
iniinc(liale neiLrldmilindd ol' tin' trulclies. conic down Ihe sides of llio
vallc,\< i|iiiM llic icvi'i-lo|i|icd |(latean altoxcand nun,t;le with llie lahi.s
of tiie idck.s winch these valleys cut. to form llie ju'cscnl frnlcli irrav-
els. The snrfaceof Ihi.s level plateau isshown in I'l. X\\\'I. It rises
(liidor 7inM'ecl aliove the \'ukon Flats, and is everywhere covered,
accordinL'' to prospei'tors. with these waterworn irravels. Ml'. [{. (i.
.■McCoiinell' lias iioled mi the ]{ocky .Mountains, hctwi'eii the .Mac-
k( I'/.ic anil the i'orcupinc. teiraces up to l,."iii(i I'eet above the sea;
anil aloni; the i'orcupinc, silts, sand.--, and tri-axids, the latter otteii
ver_\' coarse, wei'c not iced at \ arious | mi ills up to ele vat ions of -lno or
5(111 ft ct al)ov(> the ri\ er. 'I'lic same iieolonisi reports that aloiiu the
Slewari Ki\er tlier(> is a constant reciiirence of hiirh i:ravel terraces,
most of which i.i'c more or less'aiiri*' • .is.
Althoiiiih I he uiiiM'ls (Ml the lower i ' ver terraces are ilonlitle>s duo
to stream action, ihose which arc more i
wliicli lie on rock
•\ated, and esiiecially those
■cut hcnehes, iiiiist he due in lai'ire part, to marine
ai.'lion; or, if iriuinally river uraxels, must have lieeii redist rihiiled
liy the sea. for these upper le\els have not l)een .sub.ji'ctod to river
erosion for a loiiij period, while
I'll in late ueolouical times
iliider tl an watiMs. We may therel'oro exji
till
• ii'iavcls tl
be almost nuiversally found below a heiniil of .'>,oiiii feet almxcthe
soa. in places where they have not been stri|)ped olT by recent erosion.
AM 1 1; NT (ill.Cll (.1: W |;Ln.
In t he bottoms of the nari'ow^ii Idles u liich led i he lai'irer si reams
the acciimiilat ions consist chielly ni' anu'iilar rock t'raj;iiieiils, uhicli
slide down from the steep ^;ulcli walls and form a deposit that shows
little of the sort ill jr and weariiii; ad ion of water. These deposits are
therefore ilisli net in nature from the well-rounded jrravelsof >hc larjjer
streams. .\s the jiiilches wear down their beds, portions of the older
aecumiiliitions are soiiidimes Idl on the sides of the valley in ii iiiaii-
ner analo^ions to the I'ormal ion of the uravel terraces of the larfier
stream^. Thus on .Moose (reek a deposit made up of angular and
subaiiiiular iiebblcs ami bowlders of schist, sehistoso ^raiiili and
iliiart/. occurs in the bottom of the \alley and on its siiles up to a
lieiKlil ofsexcral hundred feet. The deposit shows litt le evidi-iice of
'Ann. H''iit. ili'^l. Nut. llUi, Siirvi'V Oininla. V.il. IV, 1M.SH-WI. p. L'Tl)
sri'Bii.l
VOLCANIC ASH.
223
sort inn' <if wciul'jr l>.v wjitcr, llic t'r;i,u'iii''iits liciii;.' itilcil tii^'cthci in
sucli lu'lttT-skcllcr rasliidii Unit no sirat iliciiiion ran lio made- mil ;
the material seems to he plastered uiiln liie scliisi tliroimii wliidi ilio
valley eiits, and is sullieienl ly hard to Iniiii sharp ridui's an<l piimach's
iO or 50 feet liifrli.
VOLCANIC ASH.
Ill the re,i;ii>ii of the iipjier ^■|lk()ll i iiere ipcenrs, nverlyinn all other
dt'liosits e\ee|il a I'ew inches of veu^elahle hiam. a bed of \(ilcaiiie ash.
This ileposil has been meiil idiied and described bySchwatUa.' l>a\v-
siin,-' Hnssell, ' and Hayes.' Ahmu' the I, ewes this ash occurs as a
line, while powder, in a layer oiilya lew inches in thicl<iiess, bin eon-
roriiiin^' almost exactly In the surface, beiiij; worn away only in little
jfiillies. The maxiiniini thickness appears to be in tlie neighborhood
of the BijI Salmon Kivor, and even heii' il scaicely exceeds >'> or 8
inches. In S(iiii(> places there are two distinct layers, of which the
upper is direct ly at the i;rass roots and is com inuoiis, w Idle the lower
is a fool or two deeper and is separalc(l fi'oiii the upper one by a fool
or two of siratilied ri\-eri;'ra\ els. The lowei- layer is iiiteriuittcnl and
often cross bedded with the aravel. and is Iherefore walerlaid. Some
.'iO or 4i» miles below the I'ixc I'iiiirer Rapids the ash irrows vcrv thin,
and is scarcely noticed at all below the I'elly.' Oii ilie \Vhiie Kiver,
howmor, it wasfonnd by Dr. Hayes in immense (|uantities, a tliiekncss
of "•") or b'K feet beiiii;' sometimes observed.
Accordiiiir to Dr. Hayes, the eriiplion which fiirnishe<l this ash
occurred in the northern part of the St. Klias .Mountains, near the
source <d" the Kliitlan ulaciei' (shown on slieel :.' of I he majis ai-com-
panyiiiii' Hayes's report). aii<l he aiirees with Dr. Dawson in consider-
inj; thai the eriiptioii could not lia\c taken [tlace more than a thousand
years ago. The remarkably muddy character of the White i{iver,
from which it deri\es its name, is largely due, aeeording lo Di'. Haves,
to the ash which it erodes from its lianks ainl cai-ries in suspension.
Ac<'or(liiig to I'i'ofessor llnsscil, la.\crs of this ash are I'eporlecl by
.\rlliiir llari)erand l'"rank Densmore. well-known .Maskan frontiers-
men, as occurring at Fort Yukon and oulheTanana, but in general
it is rarely seen in this lower region, and where it occurs il is probably
brought down by ri\ers.
1 Al.iiit.' Alaskii s (ii->'iit RiVLT, Xew York, ISW, p. 11".,
- Aiiii, liipt. ilc.l. Xnt. Hist. Siirvi^y. Caniiiia. Vd. 111. Part I. IsxT-hs. pp. 4^1. 4tlB.
'' Xoti'soii tli.'MU-l'iii-i' t,'i-i)li.ny .if .\lasUai Hull ()i'..l. Sn.'. .\iiu'l-ii'a. Vol. I. p. IW.
'ICxpoilitioii tliri]iii.'li the Vuk.iii.listrirt: N'at. Ui.otf. Man.. Vol. IV. ]■ llil.
•''OnChi.-ki'iiCn'uk.Ht tli.< li.'ail of Fortymilo Oi'.'k. this ash is fouiul .,ti tho surfaci'. Init wan
not iiotoil ill thi' lowi'i- parts „t Fc.rtyiuilo Cri'ok This is iu uci'orilaii™ with tho iclwi of its
diTivatioii from lli'ar tin' iipp.T part of tho Wliito HiviT.
U'lt i»*i
.Jl
I • !•'
m
c]^ APT Y.n T 1 1 .
IGNEOl^S KOCKS.
Two sets of isriioous rocks haviiij: widosiJiead distribution and dofi-
Bite iiositiun in the gcoiojrical (•oiuiiin, and so possessing llu' same
value as stratified rocks in the study of structure, have alreadj- l)ee!i
described— the basal granite and tlie effusive diai)ases of the Hanipart
series. Hesides these igneous rocks there occur in the gold belt many
dikes and also later volcanies. It is now jjroposed to treat these igne-
ous rocks as a whole, passing lightly over those already discnissed.
BASAL GRANITE.
Granite is the oldest rock yet found in Alaska. In the Fortymile
district it is found underlying the ([uartzitic schists of the Birch Creek
series, which form the oldest sedimentary series known; it is also
found along the Yukon between Fortymile Creek and the junction
of the Lewes witli the Pelly, and along the Pelly to tlie Dease River,
as described by Dr. Dawson. According to Dr. Hayes, it forms the
prevailing mck of tlie greater part of the region between the Yukon
and tlie St. Elias jVIountains along the 'Wliite Rivei', and according to
Lieutenant Allen and prospectors it is exposed for a long distance on
the L^pjier Tanana. It thus forms a continuous belt, running in
a northwest-.southeast direction. This belt has been observed for
a distance of not far from 800 miles in a straight line. On both siiles
of the granite, to the northeast and southwest, successively younger
strata occur, so that the exposure of this I'ock seems to lie along the
axis of a geanticline.
So far as observed, the fundamental granite is usually more or less
schistose or gneissic, having undergone tlie same mountain-building
stresses which have converted the overlying sediments into schists.
Locally this shearing becomes so great that the granite itself is con-
verted into mica-schists. Where moderately massive, the fresh rock
is of a gray color, and often contains porpliyritic crystals of feldspar,
which in the more schistose zones become lenticular bodies or eyes.
In the slightly weathered rock the color changes to a red or brown,
which is cliaracteristic of most surface outcrops.
Under the microscope the rock is seen to be made up essentially of
quartz, orthoclase, and biotite, all coaivsely crystalline and with a
typical granitic habit. The orthoclase or niicrocline often occurs in
large, [lerfect phenocrysts. Accessory minerals, notably niuscovite,
calcite, epidote, garnet, micaceous hematite, kaolin, pyrite, and chlo-
rite, are .sometimes found in large amount. Some of these minerals
224
s
^i
hii'hr]
DIKF, R()( KS.
'>•)■
arc derived from the docoinpusitioii of llio foldspai- ami mica, wliilo
otlicrs rc])rc,scnt const i-iict ivc pruci'sscs wiiicli lia\c liccii cipii.scciiicnl
upon liic slu'ariiii,'. Tliis slicaiinir lias also operated td luiaU and
stretch tlie ori^rinal miiKM-als in ;;ivalcror less dey;ree, yet the granitic
nature is usually ([uite nnmistakahlo in the held and almost invaria-
bly so uinler the niicroscoj)e.
l-'i'oni this fnnilamental granite must he disliniriiishc(| ihc ii'usivo
frranite, which is of later ajje, and occurs frequently in dike- .r Icusos
throughout this portion of Alaska.
DIKE ROCKS.
DIKES IX THK KOHTVMll.l': DISTRICT.
Dike I'ocks ai'c e.\])oscd in varyinjr dei;reo of abundance over most
of the irolil belt, es|)ecially in the older formations. On I'"oi'lymile
Creek, however, tiiey ari' found in remai-kablc abundance, and hero
also are esjiecially oihmi to obscrvat ion, since continuous exposures are
oH'ored alonj; the walls of the canyon-like valley which the stream has
cut in late jj;eoloiri<'al times. The relation of these dilfereiil dike locks
to one another can therefore be carefully si udied, and as the nbseiva-
tious made in this limited area need not necessarily a])pl,\ to simil.ir
ro(d<s at other points, it is1hou<.dit best to study the dikes of I'mty-
mile Creek separat(dy.
Iictween the formation of the sedimentary rocks ol' the I'oi'lymile
SCI ies and the rocks of the Kampail series there was a jieriod of i,'reati
disturbance in this portion of the eartlTs crust, which Is manifested,
amoufi other ways, by the development of sehislosity in I he P'oi'ty-
nule rocks and those undei'lyinu'. Of the many dikes which are
found ill the Kortymile sedimentary scliists, some have been altered
by the shearinj; almost or fully as much as the iuclosiufi' rock. > >llier
dikes have been .sheared ihroUi;hout, but notably less tl .u the sedi-
nuMitary rocks; others still have l)een sheared only locally, \\hil.> a
<'ei'tain class hav(> experienced no dislnrban<'c wliale\er. These | he-
nomeiia can meau only that the dikes were intruded at ditVe/enl
jieriods, and that the devidopiiu'lit of sehislosity was not smldeii, bul,
occupied ]U'obably a vci'y lonu: time. A convenient, if somevhat
arbitrary division, based on structural features, may therefore l)o
nnide Ijetween the dikes which have been most and those which have
been least slieared. This is really a classilicatiou belwciMi the older
and the yonufjer dikes, since those which are most altered were evi-
ilcntly intruded i)revious to the chief development of the schist<'S(3
structure, while the unaltered or less altered dikes came in at a some-
what later period.
r,Aiii.u;u scnisTiisi; i>ikks.
Under this head are considered only those dikes which have been so
much altered as to become virtually schists, they having' exiiericnced
l.S OKOL, PT 3 15
'^
1
, i
I
i iir,
M
.11
2'J(i GKOLOGV OF THE YUKON GOLD DISTRICT, ALASKA.
practically tlii' saini- iiiiioiiiit of iiilcistitial iiiovfiiicnt as th(( iiiolosiiig
Bcliists of sfdiinciilary ori^iin. 'riicsc dikes arc not all necessarily
coiiteini)oraiieoiis in oiM<;iii, hut all are older than t lie niaxinuini period
of sliearinj;;. Moreovei,', there is no sharp lino of division botwoon
them and the dikes whicli will he considered later, for there is a per-
fecl transition in de^rree of scliistosity Ix'tween dikes which are com-
pletely sheared and those which have snlfercd no movement.
Qiiarf.~-(liiin'li-sili/.sl. — Oi\ Fortyndle Creek helow Hrown Creek
the lower Jiart of the wail of the so-called "c:inyon" is made up of a
mottled schistose rock of a K«'"<''"il dark-j;rcen color, which inclo.sos
eyes or short .seams of crystalline (inart/.. Under the microsc()|)e the
rock is seen to have the j4;rannlar structure, and con.sists essentially
of quartz, feldspar (|)la},'ioclaso predoniinatinjr), and hornhlendc.
There is also some hiotite and .secondary epidote. Pyrite altering:;
to hematite is not infreiinent. The wlioii' rock has heen sheared, and
in places the minerals have heen };ranulate(l.
Dioritt- (IV si/cnlte-NfJilat. — On I'ortymile Creek helow the Forks are
great ma.sses of a dark-green rock with schistose structure, which,
howe\-er, in places becomes coarse and massive and cari'ies lartto
phenocrysts of hornblende, lietween this massive rock and the line-
grained schist there are all stages of gi-adation. Certain pinises also
contain mncli hiotite, which takes tin? place of hornblende. A s|)eci-
meii of tliis schist, .seen under the microscope, ajipears to have for the
predominatinji mineral orthoclasc, much mnscoviti/.ed; also some j)la-
gioclase and (piartz. Fresh brown hiotite, very likely secondary, is
present in large quantities; and colorless e])idote, in sniall crystals
and in irregular grains, forms a large proportion of the rock.
Diorile-jM/rphi/rij-scliisf. — ( )n the South Fork of Fortymile Creek are
large areas of hornhlonde-.scliist, some parts of which are fine-grained,
while others become gradually coarse and develop slim hornblende
phenocrysts. Thes(> phenocrysts are usually arranged in a ra<liatiiig
fashion, and give the rock, when coarse, a very striking a|)i)earance.
Specimens of the more schistose portions of this rock are not always
easily distinguishable from the hornblendic schists which have
resulted from the alteration of the impure Fortj'inile sediments; but
the line of contact between the two is ordinarily well marked, and in
several cases this line of contact was seen to cut across the scliistosity,
showing that the coarser and more massive rock was undoubtedly
intrusive. A s|)(>cimen of one of the liner varieties of this dark-green
schistose dike rock shows under the microscope jihenocrysts of feld-
spar, whicli are much altereil to epidote and calcite. The groundmass
is mostly orthoclase, with plagioclase and green hornblende. There
is also consideral)le ejjidote, and iirobably a little quartz.
The few o.Kamples which have been cited show that the extremely
schistose dike rocks of the oldei' .series appear to he dilTorent phases
of the diorite family. A few dike rocks from other localities which
Hi'
HI
si'rim.l
DIKE ROCKS.
227
I
liiivc experienced the same amount of sliearinj;, and are tliorofore
probably of the same age, will be described later; and it ai)i)ears tliat,
so far as observed, they are all varieties of the granite and diorito
families.
LATEIl USSHEARED DIKES.
Most of the dike rocks which occur so abundantly on Fortymilo
Crock are only slightly or not at all schistose, and often cut directly
across tlio schists, so that they are evidently of later age than those
dikes whicli liave been altered at the same time with the inclosing
rocks. In these dikes there is a marked variety, and the difl'erent
rocks seem transitional into one another, so that all stages of change
are represented from extremely acid rocks to extremely basic.
EXTHEMKI.Y llASlt! IIOIKH.
Rocks of this character are abundant, iind are present in dikes of
considerable thickness, also in nuuicroiis small dikes and stringers.
They are nearly black, and often coarsely crystalline, and so have a
striking appearance in the field. They are usually (|uile massive,
with no appearance of schistosity, and yet sometimes slmw evidence
of disturbance by the presence of joints and small faults.
Pijroxenite. — One phase of the extremely basic dikes is l)lack and
usually coarsely crystalline, with finer-grained, greenish bands. Much
jiyi'rhotite and other nic1alli(! minerals are recognizable in the Iiaiul
specimen. Under the microscope the structure is seen to be coarse
and holoerystalline, and the rock to be made ui) almost wholly of
green or colorless augite, with a small amount of green hornblende
and some brown biotite, in irregular strips. Some of the augite shows
zonal structure. Pyrite and pyrrhotite are present in considerable
quantities. There is no (piartz or feldspar.
Another dike whicli appears originally to have been of pyroxenito
is altered so as to consist niostly of librous serpentine in radial,
parallel, or felty aggi'cgates. In the serpentine are numerous lem-
nants of augite, from whicli it is undoubtedly derived. Magnetite is
present in moderate amount.
Ilornhhndite. — Another dike having nearly the same appearance
and the same habit as the pyroxenite, and occurring so close ;o it
that the two are probably varieties of the same rock, is found under
the microscope to consist essentially of green hornblende with very
abundant epidoto in crystalline prisms and irregular grains. Pyrite,
pyrrhotite, and ilmenite are present in large quantities, so that small
pieces of the rock are readily attracted by the magnet. No quartz or
feldspar is present. In the hornblendite are nai'row bands of bright-
green rock, which under the microscope are found U\ be made up
entirely of epidote. These bands have probably formed along .joint
planes. Similar bands are found at the contact of the hornblendite
with the aplite which cuts it.
'M' ^i
*
rffa
m
L'-28 OKOLOOY OK THE YIKOX fiOLD msTRICT, ALASKA.
/'ii/iiiiifiHc Imnihh iiih-i)inlliiiji-liii>lili ,iirl;.—{)\\ KinM yiiiilc C'rcok
almvc Siiiilli Creek IIiimc (iceiir slici'ts aixl ci'oss-ciitt ilijr ilikes,
iirii'ii l.'i (.!■ I'll feel ill lliii'Uiii's>. 1(1' ii scry coarsely ••rystallino (lik(»
roek, which is made up of iiiiiroiinly iai-,i;e crystals of horiihleiule,
pyi'oNeiiile. anil iiiica, iiilerv'r')" ii in i)e;riiialiti<' fashion, eaeli eryslal
l)einf,'aii inch or Iwo in Icn^rlh. A specinwii lakeii oT Ihis roi-k i-
sisls appili'enliy of iilioiiioiphic cr\stals of horiihieii(le and liiolile
interj;ro\vn, each crystal liciiii; alioiii -1 inches in ieiijilh. On account
of the c.\lr(!inely coarse texture, only a single crystal was shown in
the sliile, ami this was taken from a slijiht ly ilitVerenI portion of thu
rock. It consists of ilijilla;,'e with po'ciliiic struetnre, containin;;
man\- sniail in<'iiisions of brown ami i;rcen liiotite, ami crystals of
hematite or ilmenile.
INTKIIMIJIIAII: lliH K~.
/'o;y/(///'/7/c liiinilili ikIi-si/i iiilr. — 'l'Uix rock is dark-colored ami
basic ill appearance, contains mueh pyrite and pyirhoi ite, ami also
many jicrfect crystals of feldspar. I'mler the microscope^ the strnc-
tliro is seen to lie nearl\' |ianidiomoipliic. The roek <Miiisists mostly
of dark-fireeii hornlilemh'. with some chlorile. The fcddsjiar is nearly
all orlhoclase. somewhat altered to miiscovite. There is a small
amount of (|narl/. as an orijjinal conslilueiil. which shows piecilitic;
sirncture and incloses small crystals of hornlilende.
(Jii'irl-.-liiinihlt ii(l( -ilinrili . — This dike roek is dark-coloivd, mass-
ive, and eoarse-;,'r;iine(l. In the hand specimen it siiows plienoerysts
of I'eld.spar, white or pink in color, and some quart/. I'lider tho
luieroseoiie the structure is seen to lie coarse and uranitoid, with a
(cndeney to porphyritie. The eoustiluent minerals are chielly feld-
spar, with plauioclase predoiMinal ini;', coTisideralile quart/, ami much
hornblende; some aiiiiite, maniiet ite, and chlorile also occur, and an
occasional garnet. Often the rock shows a tendency toward tlio
IMeeilitie .structure, the fcldsjiar plienoerysts c<intaiiiin^ tuimerous
inclusions of (piart/.
This roek and the one last descrilieil are jirobaldy varieties of the
same n'ciieral l,\l>e, since they occur close 'oi;etlier in a series of dikes
of flic .same a^e and the same apiiearauce, and since one seems to
pass j;i'adually into the other.
{liiriilili nth -ijnnilli . — This rock < urs in irreat dikes in the inarblo
of the l'';irtymile formation. It is dark-colored and j;neissie in
appearance, an<l becomes locally schistose. I'lKler the niicroseopo
the structure is granular and hypidioimir[ihie. The essential minerals
are oi'thoclase, lioriilileiide. and (piart/, with considerable i)lai;ioelas((
biotite, miisco\ite, ami epidote.
Fine-(jni!ii> <l lionilili'iKli'-ijnniifc (iiorphiiriticfdcirs). — < )n the ridgo
betweo!! Chicken Creek and Fortymile Creek, overlook iiifj; Mosquito
Fork, is a great dike of dark-gray, iiiediuiiily line-grained rock, hav-
ing a tendency to a iiorjihyritie sliiicture. I'nder the niieroseope tho
i
DIKE KOi KS.
2l'!l
I'dck is seen to 1>(' csst'iil iiill.N a Inic ^ranhi' with |iIiimiimm\ >ls nl IVid-
spar. siiiiill ami impi'ilVctly (lc\ c'ldpcil. 'I'l NM'iitial cuiisi it iicnis
ail' iii'llniclasc, (|ilart/., ami liDiiililcmlc with sdiiic liiotitc. 'I'lic scc-
(imlai'v iiiiiu'i'als arc ciildrili' ami cpicldic in cdiisiilcralih' ipiaiilit irs;
aisd lieiiiatitc, I'alcitc, and aiM iridlitc. Mairiii'liic ami iliiiciiilc aid
locally ahiimlaiit. The iiK'k has tlii' iiiiiiciai cdiisi it iicni'. nf ^iiuiiic.
ami .\t'l Ihc proportidii of the (IIITcrciii iiiiiici-als is such that the incU
is decidedly liioic basic than l> pical y;ranilc.
I'lii-jihiiri/. — A specimen taken IVdiii a iliki' nn the ri<l;;e liriuccn
Ciiicken Ci'cek and Foi'l \inile (reek is ol' considerably weiilhered
I'iK'k, of a K<'i>"''"'l y:ray color, with phcnocrysts of llcsh-cdldicd I'dld-
spar. I'nder the microscope llm phcnocrysts are I'onud to lie iiiinh
allereil td milscdvitc, lull seem to he nl' prcddininal in;,' drlhdchisc
will) some iila.n'idclasc. Areas df chldriic prolialily represent driy:iiial
phcnocrysts of hiotite. The ;;rdiindmass is tine-nraiiicd ami holo-
ci'\ stalline, and seems to he maih' up chiclly of orthoclase. (pmrl/.,
and innscdvitc.
(Jidirlz-dliirili , or (/riiiiniHiirili . — (In the rid;;e heiween l'"ianklin
(iiilch and Chicken Creek is a ;j;rcat dike of coarse-irrained rock which
lias the appearance of an aei<l trranite, Ixili;;' made up chiclly of feld-
spar anil iiuart/., with a distinctly siihordinaic aiudiint nf hdrnlilend(t
and mica. This rock has a li^ilit I'ray enldi', l)c<-diiiiii:^' riMldish di-
pinkish on weathering:. I'nder the ihicroseopc the essential feldspar
is fdimd Id he pla;;idelase in stoiit prisms. Next to the pla.i,ddelase
the most ahundanl mineral is ipiartz, ami there is also cdiisidcrahle
orthoclase. llornhlcnde and hioliie occur spariiiuly and in small
crystals, althoii;;li rcuularlv cnoiiuh to he classed as e>sciitial cim-
stiluents. Titanilc and ma;:iielitc are yi'iierally [irescnl. In smuc
jiarls of Ihe I'ock inici-dyraphic intcrurow I lis of (juarly. ami fcldsjiar
occur.
Arrii KIM KS
CI rtiiH/ir iijilili . — This rock is liyht-^ray in coldr and line-^riaincd,
and dcciirs as a nai'i'dw dike cutliui: nidii hasic dike idcks. I'mler
Ihe inicrdscdpc it is seen to he made up chiclly of drthoelase and
(piarl/. in lar;;c hypidiomorphie ;;rains. Some iilayioclasc is iiiteiMrrown
with the ortlioclasc. (Jrcen lii<itite in hypidiomorphie jilatcs very
niudi smaller in size than the urainsof (iiiart/. ami feldspar is present,
ahiintlanlly and I'cjifularly. so that the rock mii;ht readily he classed
as a phase of yranitc wei'c it not for its e\ idciil relal ion ship in si rue-
lure and compdsilidii to Ihe aiilites with which it dcciirs. Kpidote in
imperfect crystals and irrejfular frrains isahumlanl. The rock seems
to be an intermediate type between an acid trranite ami an aplile.
/'((jiiKdiiiil iijilili . — This rock is coarsely crystalline. ;j:ray and i^ranii-
lar; and the structure as seen under the microscope is hi^rhly peu-ina-
toid (U- micro;rra])hie. Tlie rock I'oiistitueiits are chiclly ipiarlz and
uiieroeline interurown: considerable uiuscovite and some bioiilc uro
s .1 I
,, /I ;
; ^
If.
»
k ■
f
'■'^l
2;i() (iEOLOOY OK Tin: YI-KOV COM) DISTRICT, ALASKA.
;i, «!
IHi
also pn-sciit. All llifsc have tlif iM-^riiiMloid liabit ; niiil in strong con-
trast to tliriii is an idioiiiorpliir niiiiciiil wliicli occurs Hbuiiiliiiitly in
pcrrc<'t ciystals. ciiltiiiir the other niincnils and passing from one to
aiiiitiicr without (lisliiiliancc. 'I'hcsc idioiiiorphic crystals, however,
are nsiialiy consiileralil.N smaller in size than the individual trrains
wliieli have the pe;;matoid hahit; and the mineral, which is prohaWly
epidole, is undoubtedly si mlary. Occasional pyrite, altcrin;,' to
iron oxide, is present.
hiiirilic mililr. — I'lider this head are classified abundant dikes
whose essential constituents aro [tlaj,'ioclase and ([uartz. Fntexturo
the ililTerent. specimens vary from very coarso (approacliiii^,' iiennia-
tite) to extremely line. The structure also varies fnnn hypidiomor-
jjliic to panidioiiiorpliic j;rauular, and there are ureal dilTcreuces iii
the relative airKUii.tsof (piart/, and feldspar. Someid'thoeiasi,' is jircs-
ent in these rocks. i,i ^nww, c"-v,-i hiolilc; in snuill Hakes and crystals
is \ery common, while in others it is entirely absent. 'I'itanitc and
pyrite arc also found. In some of the specimens the (piart/, and fold-
spar arc intcry;rowii to form the microjj;raphic sti'uclur(>.
Oriliinirii (iiililr. — Abumlant aplites are fiuitul of a very li}i;ht-f;ray
or pure-white color, consistinj; essentially of orthociase, tpiart/,, and
pla^'ioclasc. Small ki'"''"* '•' i'"" p.vrite ai'c usually present. Tlu*
tc.xtu re varies from coarso to very line. The structure is j;ene rally
panidiomorphic with extremely fre([ucnt mici'oij;raphie intcrffrowths,
and is occasionally fj;raniloiil.
Piiriilii/rilic tijilih. — This rock cuts the hornblondito which has
already been described, and thc(,'ontacl lietween tho two is mai'kcd
by a narrow band of liornblendc-epidote rock of a bri.uht-j^reen color.
'J'he aplit(! itself is li^ht-;,'ray and resembles a line-jiraine(l ([uartzitc,
except that the filimmcr of snuiU fcldspai' crystals can be sot>n hero
and tlioro. Under the microscope tho nu)slr strikinfj; miiu'ral is feld-
spar in nearly perfect crystals; it is usually orthociase, but. sometimes
plaj,noclase, and .sometimes both intcr;i;rown. These crystals aro seat-
tore(l I'athcr spariuj^ly through a tfroundnuiss which consists almo.st
exclusivelyof (pmrtz in small, interlocking grains, and so hasthooxact
ap|)caraiico of a lino-grainod <iuartzito. Snuill Hakes of biotito aro
al)undant, both in tho quartz grouudnuiss and in tho feldspar pheuo-
crysts, and there is a little epidole.
I\'(ltu(iHk'. — Vei'y little coarse, tyi>ical ])egmatite, such as is so
common in areas of granitii; inlrusivos, was found among the dikes of
Fortynnle Creek. As already noted, however, tho aplites vary in
texture from extremely lino to so coarso that tho rock miglit be con-
sidered fine-grained pcuinatite; and yet the transition is gradual and
without a[)preciablo change in composition or structure. In some
rocks, liowever, tho (piartz and feldspar tend to separate in distinct
bodies, so that large bunches of nearly i)uro quartz occuir, while
in other portions of the same dike the rock has the appearance and
Hl-I MR.]
UIK1-: HOCKS.
231
striicturt' of a oonrsp-graiiUHl aplito tir liiif p(';riiiatitc, hciii;; inail<' up
of i'i'!j;iilarly iiilerf^rown crystals of (piartz ami IVldspar, wiili rarely a
little liiotitc. iViiioiiK the feldspar's of tliesi aise roeks plii:.'ioelii^«
Is precloiiiiiiaiil In some eases: in others ortluielase. 'I'lieie is ^'erier-
ally a small amount of ealc-lto vuinin);, and in the liuire masses of
(piartz whitdi occur in these (li':es are frecjiient small ;,'eodes, the \miI1s
of which are covered with (piart/ crystals.
Qiinrlz veins. — The pej;matite or <'oarse aplitc just deseril>e<l ciin
be traced in one and the same dike or scin Into solid (piarl/. lillint;
the whole space between the walls. At lirst the feldspar Keiierally
becomes contracted into /.ones nearest the walls, leavin;; lliecenlial
part |iure ([Uart/,, ami linally dl.sap|)ears alto;;ether. These i|mirl/,
veins iindei' the microscope show tlu> usual coarsely crystalline, iiilcr-
lockinff structure, and besides ([imrtz contain only a little ma.!;nclitu
aud pyrite, with some calcite vcininiic which Is i)robabIy secoudar}'.
iti'.LATioss OF i>iifi:hi:m' V Aiiir,Tri>'.
Although tlic rocks which have been deserilinl have l)een classilied
under dilTcrent names, according; to their mineral composition, yet as
a matter of fact neither Held nor laboratory st udy can (li\ide llieia
into aii,v classilication otiier than an artilii'ial one. <>n the contrary,
the,v form as a whol(> a <;onnected .series with ordinarily the most per-
fect and firadual transitions connect in;; the widely ditVerin;; extrenies,
and in this series the lin<' dividing;: the rocks according: In established
classillcation.s must be arbitraril.y drawn. It thus happens that in
the rocks who.se mineral composition warrants their beiiif; classilied
under one name according to an established nomenclature, the rela-
tive proi)ortion of the coustitiienl minerals varies so that thei't> aro
greater actual ditTerences than there are between some of the.se rocks
and others wliicli, on account of the sligtitly dilferent proportion of
tlie constituent iidiierals, have been classilied under a dilferent name.
For e.\-am])le, there is a p;reater actual dillVrenee in stru<-ture and
composition between the acid and ba.sic varieties of the rock wliicli
lias been classified as liornblende-granite than between the basic
hornblende-Kranit(> and the hornblende-syenite or diorite, or Itetwei-n
tlie acid granite and the aplite.
Sogroat were the dilliculties under which these abundant aud highly
interesting dikes were ob.served that only about twenty specimens
were collected. Yet in these twtMity specimens, which were taken at
dilferent times and under circuinstances where there was little oppor-
tunity for comi)ai'lson, hardly any two are alike, and the set const i-
tntes a nearly perfect transition from the most acid tr) the most basic
varieties. Themostabrupt change was from hornblendite to extremely
basic liornblcnde-diorite or sj'enite, and between these tworo<'ks more
gradual transitions were noted in the fiehl. 'I'he nature of the trans-
itions will now bo briefly sketched.
2.'1- (iKi>l,iP(;V Ol' Tin: VI'KDN <ii>l,l) DlsTiaCT, ALASKA.
■|'li(iii(p-i liii>ii'Viiri"ty isc(iiii|M)MM| sdiiicti >cnl iiclyof Iioi-h.'IcimIc,
.s()iiii'iiiiM--nri)\ ToM'iiiii'.iincI xniicliiiK'Mif iMiili i 11 1 fiiii i iiliIimI, all.! <-iiii-
tiiiiis ,1 iciiiiiil<M")li' qiiaiilily nl' pytrliuiiic, iliiii-iiilf, pyrilc, aii<l utluT
iiiclallir iniiiri;'ls. Hills isi it Hi iiii; a r<»'k iy|ic <if rxl ii'iiic l>asicily.
'I'licM' basic r.ifks I tunc |)iM:iiialil ic, willi [Ki'dlilic siniclurc, aiitl
(ln's«' p.irliiiiixiiiiiaiii liiuiiic as well as iiyroxcnc iHiil lionililrinli'. In
(iilici- localilii's -lik.'s haviiii; , .■ same iMiaisc. i)aiiiili<nii(»r|)lii<' si iin--
tiin-aml iiiaili' up cliii'llv nf liipiiihlciidc l>i"_'iii tocariy crystals of I'dd-
■spar. at lirsi \cry spaiiii;:l.\' ami liwii in ;:rcalcr aiiiDiint. In smiio
\ariclics iiiiart/ alsn comes in. In oilier places Ihe iKi'iililenile
liec!-, ases in aniouMt pr<>porlioiiai..\ lo llic iiic-r. se of IV! Ispar ami
iHiart/, so llial llie lock In comes lirsI a lioiiihJcMcl. -syeiiile or dioritc,
ami ilii'ii a lioriil)lenile-iri'aiiite or i|uarl/-lionil(lemlc-iliorite, oi _iaii-
oijiorile. 'riie lioiiililcmle-;;ranllcs ami ilioriles seem to irraili' iliti)
one a mil her in I lie same ilikcs. ami occur in imnii'nse iiii iiisix •• lio.lios,
often several miles wide, forming; piolialily a er<''il<'i' bulk than eillier
the more acid or the aiore hasieof I lie a lie d rocks. In iliese j;iiiiiites
and diorilo !lie hornlilenile -lill I'oni iaiii'- lo he tl Iiief prominent
dark Irisilica'i'. alil ;;li bioiite. wliicli was noieil as lieinu one o' tlio
I'oiist it iii-:i's of I !;e e <iremely hasic rocks, sei'ins to increase iii impiir-
taiice in tile more acid varieties, and in tlie more ai'id iri'aliiles oft .|l
becomes predominant . |!\' this ;^radiial cliaiit;e tlii' basic lioriiblemle-
jl^faiiite, ill « hi<'li horn blende is i he most .ibiimlan! of ' Ic constii iients,
pas.ses into an cMremcly acid biotiteirr.inite, in which the bioiiMi
forms a com;iarat i\ ely insi;.niilicaiil ccMistii iient as compared with the
feldspar .iml |ii,irl/..
This acid ^rr.iiiilc, by a very sliiilit cjiaiijie, ]>;tsses intc a rock of
t'oai'st- or line liypidio.norphic jiiaiiiilar stiiielmi'. composed esseii-
'.ally of Miiart/. and feldspar, the predmiiin.int feldspar beiuir ireiier-
ally (111 iioi'lase. somei ii.fs plairioclaM^: !heri' is also ssji! ssential
liioi ite and occasiotially mnscovite; yet ! Iiese minerals are in sc.-illercMl
plai( - "f Very small si/e. In the next sta^'" Ilie mica disappea .s
aliiiosi etilirely, beiii^r found only in certain ari';is, so that the rock
b mes entirely of i|iiari/ and t'eldspar. 'I'liere is also a leiiilency In
cliaiip' from the ;.M'anit 'c to a paiiidioinorphii- si r net iire. and I he n.iii-
erals form peirmatoid or microLrrapliic inter^'row t lis, 'I'Ik'si' nick.saro
soiiietimi's very liin' u:ra'ned. and soineiini 's are coarse lik<' uranites,
I till all ha\ e esseiii i.il!'.' I lie same -.I iiicl lire and con isilion. and lia\ <)
been cla ilieil as apliles. I 'I I liese apiile-. the ch,ini;c cinit iiiiies by t he
relalMe increase of cuiai'lz and < ■crease of 'enispar. A remarkablo
jiliase uttendini; this is a rock eonsistiii;; of scaltcred iihenociysls of
feldsp.ir w itli a ^roiimimass of line (|uarl/. in small iiiterloekiiiK^'rains,
w liicli has in the lie hi and iimler the microscop" the ex:icl appearaneu
of a tiiie-;:rained (|uarlzite. In coarse \arieties of the apli..- both
(piarl/ ami feldspar I me nioi'e coarsely ci'ystalliiie, so that the roek
ajijndiK'he.s pegmatite in si riicl lire The next st ago after beeomiug
m
n
niKi; icdiKs.
•j;<3
coarsely crvt-lalliiii" is I lit- si'|)ai'ai ion >>\' I lie two iiiiiii'ials iiiici ilisi ind
areas. 'I'lic i|iiai''/-l'i'lils|)ar ilikeN cuiilaiii laii:c liiiiicln-- nl' mviily
jmri' i|iiai't/.. which lias all lln' chaiactcrisi ics uf vein (|Man/. Willi
the |)i-cpi.'i-essi\(' increase in acMily the leidspar hecduics reslnciiil in
cerlaiii parts et' the \eiii. sonieliiiio iireixiijarly ami si.iiici inie-. cdl-
Iceliiii,' near tin- wails, while 1 he pin'c i|iiail/. Iie> in the cciiler.
I'inalh' the felilspar (lisapiiears allcitiCther. ami I lie \ ciii ln-ciiiiics pure
r|iiail/, Willi oeeasiinial |>ynte, ami now aii<l lln'ii a cr\>lal 'it Ki.iiitc.
Olleii lliere is also ealeile, especially aloiiu: the walls In one aii<l
ihe same vein the transition rroiii the coarse aplile fv line pc^jiiiatilc
;nio an onlinary ipiarlz vein ina> lie seen in all its slajies. In all
these rocUs. however, Ihe alisein I' coai'se-graiiieil pe-rinatite is
not icealile.
In ail Ihe i-ocks. from the hornlilemliles ami pyroxeiiites to the acid
apliles. I'piilole I'orins a const ani and i in port a lit iiilneral, lint is in most
casi s of secomlarv orisjin.
('onsiilerinu- all ihcse dike rock> to;;ellier. llieli, we lind thai lliey
are all made up c>>ciil iallv of a coniliinal inn of ipiarl/. fi'ld>par, and
hoinlilemie, with siiliordiiiate liioiilc and ot her rarer iiiiiierals. liy
i he di 111 rent icuporl ions w Inch thcsi^ minerals In ar lo one aiioiher in
ililVereiit dr. -s all the chief rock l\ pes enmueraled are produced.
When the three chief minerals, ipiarl/,. feldspar, and hoinlilemie.
with snliordiiiale liiotile, occur in alioiit eipial propo -i ioii>, tin- rock is
a hornlileiidc-uraiiite or diorilc. i'"idiii t his iiileriiiediate pliasi' varia-
tions are produced li.\' the increasiiiir aliniidan f basic iiiineialsti
the cxeliisioM of acid oiie>. or li\ llic reverse proi'cs^: . thai li\ casv
slajics one cMiciiic is reached in a lui-k eoiisi>tin,u eiilircly of horn-
lilemli and other dark liisilicat«'-«, such as pyroxene and hioiite. with
lai-iic ipiaiilities of nielalllc minerals, and llie other e\ireme in rocks
consislini;' cut irely of ipi.trt/ and feldspar, which liy incicisiiii;' ai-idity
{.craih into (piart/. \eins.
nia.A ii\ i: M.I
lolMVMMI hiKi:~.
'riieie are I wii criteria lor determining I he relal i\ c a;:es of the I'orly-
niile dike*. The lirsl is the one uliich dcpciil-. upon I he oli\ i<i,i-. and
('hMneiit.;r\- principle llial if cme dike .ills il oiiiih aiiol her \. ilhoiit
inlerrniilioii it i> yoiinuer in at;e. The. oi In >■ .■epciid> upon the rcla-
live aiiioimt of schistosily which Ihe \arioiis dike roi k-. show, the
seiiis'osilx- lieinn' Ihe record of d\naiiiie forces which lia\c o;ieralcd
diirini;' a more or less cMcmled period, and w ho^e iiia\iniiiin nx'ta-
nniiphism is measured by the allcral ion into schist> and niarlilcs of
tlr^ sedimeiilary beds of Ihe l''ortymile series. When dikes ha\c
experienced the same amount of metamorphisiii as the iindosini; sedi-
nieiilaries it is certain that they existed in l!ie loek w hen dynamic
disliiiliaaees be;:aii; and, on the other hand, dikes whidi show no
slieariii , whatever, bill form nia^'^ixe bodie•^c It iiiL' across the schis-
M
WT
'^
f.v
u ♦
'23A UKOl.OCY OK THK YUKON (lOLD DISTIUCT, ALASKA.
lose roi'ks, were not ])roseiit (]ui'in>: tlio jierio'.l of iin'(iiiiiori)liisin, ami
so must 1)1' distinctly yoiiiijfcr ilian tiic slicai'od dilvcs. Iiitcrniediato
between 1li(>se oldest and youn^jest dikes ai'e some wliieli iii'o sliy:litly
slieaiu'il til roil jriii 'lit, or are locally schistose and locally massive. These
must have been inti'iidcd diirinu: the jieriixl of iii<'tamor])hism, so that
tlicy havesiifVireil only the tinal el1V<is, and therefore they are yoinif^er
than the completely schistose dikes and older than those which have
siillered no metaiiior|ihisMi \\hate\('r.
'rill' most schistose dikes found on Fortyinilo Creek, so I'ar as
observed, are variou.s phases of the diorite family, which may ho
classilied as dioi'ile-porpiiyry, (piartz-diorite, or syenitic diorite.
Anion}; tin? rocks whicli are partially schistose the hornblende-jjranites
ai< iispiciioiis. oeciiiriii^j abundant !>• in immense dikes, and beinf;
somet imcs u:ieatly am! soinctiiiies sii^rlitly sheared. Jfost of the other
rocks show very little evideiio- of shearing, either in the basic or in
the acid tyjies. The dilTereiil varieties of ultrabasic I'ocks seem to
frradc into one aiioiher. and are usually '|iiite massive. They have
in places, however, been jointed ;iiid faulted, and in this respeci
they contrast with the ap'.ilc dikes which cut them and which have
not ex])erieiiced the same f.iuil inji'.
Considering: the (|uestioii of aire from the cutting: of one dike by
aliotiii'i'. it was observed that the basic honiblende jrranite, wliicli was
sliy:litly schislove or trneissic. was cut by dikes of porphyritic liorii-
bli'iide-syeiilte with firanitie facies, a rock markedly more ba>;ic
than that ihrcuiirh which it cut, but not at all schistose. IJotli of
these dike roi ks are in turn cut by small dikes of orilinary aplitts
and of ,iriaiiili<- aplite. Thus in this |),irt iciilar case the relative aj,'o
of the three dikes which intersect oiie another is basic hornblende-
frraiiiJe, hoinlilciiilc-.syenite, and aplile. The iiciieral rule on i'"orty-
mile Cii'ck, however, is that when two dikes intersect the mori' a<'iil
one is sliown to be the yoiinirer. In every case where ajtlite dikes
were observed they cut ail others. In one case an exl reniely acid
ajilite, consisting; essentially of small plieiioerysts of feldspar in t\
};i'ou lid mass ol' liiie-ejrained i|iiart/, 's found cutliiij; a. rock consist iiif^f
aliiKisl entirely ol' hornlileinle with much pyrrhotile ami other iiieial-
lic minerals. The (|uart/. veins into \\lii<'li the aplite dikes often
chanv^e also cut the schists and dike rocks without disturbance, and
show themselves likewise to be anion;; the yoiiii;;est rocks in the
formal ion.
The order of intrusion of l liese dike rocks seems, then, to be ill };eii-
eral: I''irst,a series of dioritic dikes with i;ranitic facies; second, h
series of more basic diki s, I mi still of the urranitc and diorite families;
next, a scries of still nnu-c basic dikes, which sometimes reach tlio
extrcii f basicity, as exhibited in tli" hornblemlites and pyroxen-
iles; and, linally. an abundant .series of \ery aciil dikes, belon^dn^;
chielly to llu' apliti' j;roiii> and inerj;iny: into (iiiait/, \cin8.
i:V
n- I
niKF. ROCKS.
REl ATIVE ABirNI>VN( K uf IillKKUKNT 1>1KK HOCKS.
235
Altliou^li iiPiirlyall tlio dike ntckn (l('s<'i-ilti'(l occm- altiiiKlanlly, tlm
types wliicli arc intornicdiatc in <-li)M)ii<-al cimiiMisilinii m'cui Id foi'iii
tlio laru;('st masses. Next in rclalivcalMiiiiljiiH'i' coinf llic a<'iii iiuarl/-
feldspar rocks, wiiicii (leciir in iiiinieiise (jike^; and. linally, llie nidre
Imsio rocks, whicli, wliile still vei'v alinndant. are appaienlly smiie-
whal less in amount tlian eitliei- the aeid or the inieiiiiedlale irroiips.
iHKi"..s oi.' Diia II ci:i:i:k insriiii t.
The l)(>d-i'oek in the liireh Creek niiniiii; district is almost entirely
<iuarlzite-seliist, \vhi( li eunlaiiis Ireciuent dikes, aithonuh not nearly
so many as on I-Nntyniile (rei'k. 'I'lmse noted. ho\\e\ ei-, are interest -
inj: in that Ihey i-epresent inlrusions lioili earliei' and later than Iho
(Ie\elcipment of sehistosily, as in the I'orlyinile disi riel.
Sliriireil (jninili nr (jrniiiHr niIiinI — (n the ;;ray ipi.-irizile-sehists on
lloit'em or Deadwood Creek a mass ol' darker-<'olored. more inassivci
schist was oliserved. The contact lielween this and Ihi- ordinary
quai'Izite-sehist was widl marked and ran nearly at riirlil ani;les to
llie schislosily, and when <'losely (d)ser\ed the darker rock sle.wed
small crystals of feldspar, often eloiiirati'd into lenlienlar eyes, so that/
it was e\ ideiitly a ilike. Th" planes of seliistosiiy traverse Imi h diko
and <'onnlry rock, passinir from one to anothei' without inlerruplion.
In I he dike, ho\\i\ cr. I liey are fewer, so that this has a nioi'e massivo
appeai'anee. In both rocks are (luartz veins which ari' nonpci'sisteiit
and are often lient and folde<l.
Iiider the micioscope the dike rock shows a caiaelasiie sirueiure,
hul the indixidual ^jrains ai'c lart;e and uniform and irive no si;;n of
delrilal orii^in. The principal minerals an' (piart/, orll'oelasi'. and
))i()tite. the latter altered lo ehlorile, act i noli I e, hemal ile, ami I'ar'liou-
a(os. The feldspar is somew hat muscov ii i/.e(|. In more ■.ehislose por-
tions of the same (like the struct u re hecomes markedly laminated, and
the liner nniterials are arranu:eil In laxei's inclosing; fre(|Uent laru'e
grains or eyes, which are somel imes orllioelase, much alti'red, ;ind
HOTni'l imes crushccl quart/. The liner iiii-losinu: malci'ials aie ^'rann-
laled ipiarl/. and fri'sh liiolile, and muscov lie in trrains; pyrile is also
nliiindanl. In lliis laller case Imlh nncas seem lo lie si ndaiy.
l^ii.sliKin il i/rdiiili . ~iU\ llofi'em Creek for li miles or more aliove its
.junction wilii Crooked Cre(d< there are no I'ock onlerops, the rej;ion
heiii^j: occupied liy a nci-.rly level deposit of ill-assorted, anirular frag-
ments, which has lieen deserilied aliovo as probably torrential nu 'rial
hronuhl down by the streams from llio hills and deposiled aloii;; the
inarjrin of ji i,'real lake whiidi is now drained. On reach inj,' the shore-
line of t hi:, old lake the '.alley of I he creek chancres siiddeidy and solid
rocks appear. The lli'st ouli'rop is j.'ranil<', which is exposed for a
distance of al)oul .'i miles aloni; the creek and then ^'ives place lo
'i i
;t
Pi
•J.'K; (iKol.OliV OK Tin: YUKON GOLD DISTRICT, ALASKA.
schist. 'I'lii- irijinilc is li^flit ;.'r,iy in cdIih' and is of avci-jiirc acidily,
cciiitaiiiiiin niiicli c|iiarl/. It vaiics in Icxlnrc I'lnin rallicf lini' wlicrc
lirsl noted lu cciaisc. and even imrplixiit ic Tailln'r up. It lias i'.\|)c-
ricni'cd iiu slicaiinu and mniains no (|iiail/. veins, and is tiieretore
later than the \i'in-liearin};(inart/.ite-sehists whieh ai-e associated with
it. The \aiiati<in in ie\tni'e also points to the same eonelnsion. This
liioad dike rnns in a nearly cast-west diieetion. and eiits IJoiilder
(reek as repi-eseiited on the map. It was not oltservcd on .Mammoth
Creek, and if it e.\isis at all there it mnst lie iimlernealh the lake
deposits, as represented.
This ;:ranile coirsisls esseiitiallx' of orthoelase, cpiartz. ami hiotite;
there is also rnieioeline and occasional plai:'ioelase.
Qiiiirl'.-fi lilsiiiii- iliki s. — In some places in tic iJirch (leek district
wei'e fonnd dikes or \eins of (piartz and feldspar similar to those
desciilied on l'<prtymile (reek. These Veins are often ca\'crnous, as
in (piartz \ eins u liicli do not contain feldspar, and t he feldspar vai'ies
in amonnt. somet imes bein;^ cipial to I lie quart/. Inder the micro-
scope the feldspar is seen to lie mostly orthoelase, althoujih occasion-
all,\ the multiple Iwinnini!' of |ila;;ioclase is shown. Feldspar and
<|n,irt/ appear to have crysialli/ed in laryie part simnllaneonsly. since
licit her has its iciiiilar crystal out line. .Mon;.' st roni: fraci nres w liicli
tra\ else liotli (piart/. and feldspar small crv -t a Is of iiiciii liiol it e ha \ e
formed which fray out into the cpiarl/. The wall roc'i, of these \eiiis
is a micaceous (|iiarl/ite schist, pidloiinilly altered. Iiider the iiiicro-
w<'ope many parallel tract iiii's are seen in it, which curve slight ly at
times, so as to inclose a lenticular area of ipiartz. Aloni; these I'lai'-
t II res fr;'eeii liioiiie is pleiit iful, and occasional el n nips of iion c.irl ion-
ate and oxide seem to represent I he d nil posit ion of pyrite.
A/ili/i . — .\s on l''orlyniile (reck, these (piart/lchlspar \ eins seem
to lie dire -tlN connected with dikes of aiilile, which were oli.served at
dill'creiil places.
iiiKi;s (IN AMii;i( AN ( i;i:i:k.
m
On American Creek ii<>ai'the rpjiei- Canyon twn dikes cnttiiiirthe
rocks of the Uamp; rl series were noted. .\ltlioui;h t lies iir only
a short distance ;\p; rt, they lieloll;;' to e\;ictly opposite t\pes.
.\jilili .- Ill I he w ills of t he creek was found a n.iriow ilike of i;ray-
isli-meeii, medium- iiaiiied rock with occasional simill pheiiocrysls of
feldspar. I'llder 1 lie microscope the rock is seen to con -.i si essentially
of feldspar (cjiiclv orthoelase) and ipiart/, w it h a lariic ainonni of
epiiiote; some pyiteisalso present, and calcite in secondary \eins.
Kpidole is ill lar;.'!' crystalline masses with perfect clcaxaire, and also
in smaller crysia line ^rraiiis.
Miiii-liiiiiiintjiliiiri . Ill a small ;riill.\ whi<di runs into Anierii'an
Creek at the l"pi,er Canyon a dike of a daik-;:ray. r.-iiher tine c:iai I
rock coiilaiuing simill iilienocr\sts, ajiparently of feld.spar, was iioled.
hi i»
mm
hfl IIB.)
DIKK K(>( KS.
•-';5;
'I'liis I'ock Wits (Mmsidcrab'y tiltcicil, uikI imhIci- the inicroscdiK' ilio
i)lH'ii<"'rvsts wci'c seen lo lie mailc up cnliii'ly >i\' xcomliirv ilii-diiiiiii-
sitioii iii'odiicts. Tlii'sc idicmicrvsls ai'<'M'i in ,1 uriiiiinliii.iss in wliicli
tliore ail' iuaii\ frt'sh liiuiitc cfysliils, wliicli ai'i' in luin miiimiiiicIimI
hv 11 trroiiiKlinaj^s w liii'li \ ai-ics ri-mn faintly inicriicryslallinr In aplia-
iiilic. 'riicrc is siiiiii' (|iiail/.. wliicii may he drrivi'il licun allcralidii
III' llic ariiuriiliiiass. and laui'li calrili' wliicli aiiparcnl !> has a siniiiai'
ofiiria: niajrndilc in ciyslallini' I'lirni is also |in>i'nl.
lill.All-'N 111' DIKKS Ti> S( Ml--Tii'~n V.
'I'lic riM'ks tlirmijrli wlucli Imlli apliii' ; . iainpiopliyri> cnl. Mlllmnuli
not I'Mlii'ciy alloi't'd, lia\ (• undi'i'iiniii' in /niirsa Im-al sliraiini;. Knlii
llic dikes nicntiiincd snMii In lii' laid' llian llic di'Vi'lnpMirnl nf lliis
slii'ai'iiiir, as is ('Specially well sliuwn in llie ease of llie niiea-l.iinpio-
pliyre, wliieli ents acrnss a /one ot' i;ieal slieaiiny' neai'l\ at riiilil
annles. ImiI shows an s<'hisliisil\-. In the sheai- Z(ine, near !li niael
W ilh llie dike, there ha\e been develdped \ eins (iT w llite i|llarl/ and
Ills III' pyrile. It seems plausible I hat deposit inn nl' lliese
iiiipre;;liat |i
xeiiop'nous iiiinerals may lia\e been
the dike into the pleexislillU shear /.o
-1 iniiilated li\ the inl riisioii oL
;*•'«(
DIKK.S UN Till-; V1K<1N i'.isi.nW i'l i|;T V M I l.K ( i;i;i:K.
Ill the sedimeiilar\- series alonji- the \ iikoii imiiiedialely below the
lliollth of [•'olt\ mile (reek thi'l'e are oeeaslolial acid ilike:
( Ine III
tl
lese eollei
•led near the moulh of Coal (reek is \ ei\ li-hl -.i;ray in eolor
and line-.-rained. with -mall pheiioeiysts. It is a poipuyry of exactly
(he saiiii' l\pe a> is round in \arions parts of the ciinnlr>. and is
iiliiiosi identical with dikes round cuttinii' the Coast l\'.ini;<' manile in
the vieiiiily of llie Chilkool I'ass. I'ndei- Ihe microscope there iire
\sls of biolile and feldspar, cliielly orti iase. in a
seen small plieiioci
linc-irraincd irrouiidina-
I i|Uart/.. orllioelase
and iiniscoN lie, w 11 h
«()iiie i>la.i.;ioclas
and biolile. The microLirapliic structure is frei|Ucii
ItlKI'.S IN Till'. l.ciWI'.l; ItAMI'.MM's.
In the Lower Kampaits from
sional dike roe
were louild. coiini
or ipiait/.-diori
Ic. l-"roni the -clii-l- of Ihi
I'orl Hamlin to the 'raiiana occa-
.tin;;' chielly of schistose j;raliite
I nrcll ( reck series on Ihe
\'ukon, aboil
■*!•
I la miles alio\i' the moulh ol llii
w as taken
•n of liiie-jiraiiie.l Lrra.N rock uith radiating bundles of f,'reeuish-
lilack, libroiis liornlileu
le. Indci' t^ic mieroscope Ihe rock was seen
1) ('(Uisist essentially of i|uart/. ami actino
ile, wit h some teliNpar am
biolile anil small (|uautities o
f I'hlorile and liiuiiat ite. The virucinie
Is profoundly scliislose
iiK'hisiii^' rocks it is probably a dike, am
but from the relation of this rock to the
d inav liavi' been oriiiinally a
([Uail/.-llorilblende-dlorile, or
a horiiblciiiI.-,i:raiiile
%
2.'58 GEOLOGY OF THE YUKON GOLD DISTKICT, ALASKA.
(^)ii<irl.z-iiiii-ii-(ll(>rili'. — Alioiit. •'!•") miles below Mynook ("reek dii (lio
\'uki)ii there oecui's a liiie-jrraiiied, vefv slif^lilly seliislose roek, which
UlKJel' I lie iiiieidseope appeals In he a typical <iliarl/-lliica-(li<)rite.
This ruck is rr'esli, hiil iinlhlnji Is klluwii uf its i:e(iloi;ical (icciii-peiice
cNccpl that it is cut hy the irreat dikes of u'laiiile described below.
(I rniiiti III- (/riniiiiliiirili . — |''i'oiii -J') to \'> miles below .Mynook Creek
eoine in jrreal masses of li,i,dit-f.'r'ay massive i;raiiite, which are iiitrii-
si\e ill the older rocks, ;is Iheir contact |ilielioiiiena show. Two eliief
dikes were noled, one of which was se\-erai miles in width. 'I'his
;rraiiite vai'ies from rather line-jiraineil to very coarse ami iKirjiliyritie
with lari;e pliciiocryslsof feldspar. It is succeeded farther down llie
\'iikon by the liiccii dial>ases id' t he Uampart series, and it is there-
I'oic |)riibable thai I he ilikes are iiitrilde(l into this series. TIk*
<piarl/-mii\i-<liori''' ,dio\e descrilii'd was found at the contact with
the lii'aiiile and from :1s iMc;,'ascopic charaelers i1 is probable that
it is a local elVeet of conlacl meiamorphism. The granite consists
esseiitiall.v c)f feldspar, cpiarl/. and blolile. The feldspar is chiefly
orthoelase, although In some cases plairlixdase is predoniinanl. Zir-
con, apatite, 'ilanlte, iiiaLiiiellle, and hemalile occur abiindaiil ly as
ai'eessories,
lHarilii «/)///<.—( iiltlinr the diabases and diabasie tiilVs at tlm
be^:iiiniii.i; of the Lower Kamparls abo\i' p'orl llaiiilin was noted a
small dike, wliW'li is made up esseiil lally of <|iiarlz and plaiiioelase,
the former prepoiid''raiil. .MIcropci;iiial ll le inler^rowi hs ol these two
minerals «ere rem.irkably well developed. 'I'his dike had not been
alTeeted by any of I he shearing and .joint liii.; which liad aU'ecled por-
tions of the inelosiiiir rock.
oliDKH Ol' niKl'I HOCKS.
The dikes whieli have I n dcsc
d outside of tlie rortvinile dis-
trict, when separated into two ma in classes in rcsjiect to ajre, as shown
by their relation to the sehisloslly, whose devel(i|)meiit seems to have
been regional, ;ri\e the same ri-.iills as those obtained from the study
of the l-'orlymile dike rocks alone. Takiiifrall the dike rocks of the
;rold district to;iellier, then, il may be staled thaltht! earliest series
was of sliirhlly dilVci'ini; varieties of f;i-anilie and dioi'itie roi
InteniH'dlali' chemical coni|)osil ion. All these rocks are n
sheare(l. so niuch so thai, ofliMi their true iialni
of
ow miicli
(' is reeojiiiizable i
nils
under the miero.seope or by their relation to the earlier rocks. Siib-
seipienlly tliere came alxnit aseriesof moreaci<l and more basic ro(dis
which are iiiisheared. 'i'hetwo iinsheared dikes of aplite ami iiiica-
laniitrophyre on .\merlcaii Creek are only an Isolated ease of what on
l'"ortymilo Creek w;is foiiml to be the rule, namely, that both the
very acid and the \ery basic dikes were later than the dc\ cloinneiit
of seliistosil V.
ti
m
DIKK 1{0("K8.
239
A(iK OK 1)1 KKS.
So far as observed, the extremely acid or aplite dikes apjjear (o he
the voiiii^'esl ill tiie series. Tiieso dilvcs are ruiiiid eliielly on i'luty-
iiiile C'reeli, hut also, less al>undaiit1y, in tlie roeks of liie Haniiiarf
seri<'S. On Napoleon Creek the eonj;loMierate which overlies liie
Hamiiai'l series and the i''<ii'lyinile sei'ics niieonrornialily eunlains.
anionir oilier t lnn,i;s. pi
1)1)
III a|)lile am
I pnrp
l\l'V,
I lial III I Ins
loeality the dikes are older than the eoniilonierale, wliieh lia> lii'eii
ciirrelaled with llie .Mission (reck sei'ics. On the olher hand, aci 1
dikes anioni; which por|)liyry has
'11 idciit ilicd arc found eultint;
the SCI
in
iinienlai'N' sandstones and shales on the \ iikon hclow l''oi'ly-
^o liccn ciirri'lali'd
ilel'reek; these sandstones and shales lia\i
ilii the .Mission Creek series.
seems to show cither that 1 lu'
.scdimeiilary beds in the t wo local it ics arc not lo lie si liclly eoi'rclated
or thai the dikes hclow l'"iirlyiiiilc Creek iicliuiij; lo a yoiiiiLrcr imrii-
jsion. It is likely that the former is llic case, lor alllioiii;li lie- Inoad
correlation of the heils in bolli loealilics maybe coriccl. yd those
below Fortyinile Creek may bcloiiir lo an older and lliose of Napoleon
C'l'eek to a younf^er portion of the scries. In the rocks of the Kcliai
(Koeeiie) .series no dikes were obM'i'M'd.
It has a I really been stated thai I he earliest frianil ic and diorilic dikes
were inll'udcil ]Hi'violls to the chief ili'\clopnii'nl "f sclii>Iiisily. 'I'lie
sheariiijr took jilacc after the deposition of the i'oi'iyiiiile series, ami
chielly l)el'ore the forinali f the Uainparl series, since the latter
series is only sliudilly and locally sheared, much less so than many of
tliesc earlier dikes, which therefore wei'c proliably iiilrndcd. in pari
at least. Iii'forc the formalion of the IJaniparl series. Il has been
sliown thai on l'"orlymil
Creek there is exiilellce thai dik
intrnilcd at all periods between the youimcsl and the oldest, so
thai liiere is a fiiadalion in point of aire, as i
ndicated bv relative
mclamorphisni as
bv trradal ions in si ind iirc and cnmpo^ilioii
A\'e may say, therefore, that in this rciiioii there is a scries of dikes
the lirst of whiuh were intruded previous to the deposition of llic rocks
of llie Uainparl series (pre-Silurian ?) and others at intervals iii) to
ir into the pern
)l the dcposi
linn of the .Mission Creek scries
(Crelaccons?). and that llii-
rocks and ended with more ai
series beu'an Willi uraiiitii; or dioriin.'
d and more basic rocks.
#i:
VOLCANIC OK lil'KUSIVE ROCKS.
I'.MJCDZon— liAMI'.MtT SKKIKS ( DIA 1! ASKS).
iii;M;i: \i. ih.m kiciiun.
At a hiirher iiori/.on than the T'oriyniile series, and probably
liich are larirch of volcanic orij;iii.
(' rocUs w
directly overlyiiej; it, ai
'riiroiiirlioul thisscrics there are irrcil ipi.-ml dies of diaba.se, ^^enerally
t
L'K» (ir.ol.fKiY IH- TIIK YUKON (!«)M) IHSTKH'T, ALASKA.
cdivitic-hfiiiiiiK. wliii'li varies Iml lililc in sliiicliin' iinil appraraiu'O
ill wic|cl\ si'pai'aii
i(>cks ail' Iiil1'a< ii?< sciliiiH'iils wlii(
i| liM'aiilit's. Clii-i'lv assiicialc(l with llic cryslaliiiio
ii arc (lcii\rci ciilirclv fniiii iIk^
dialias.'. and wliicli lonn a very laiyv and imiioilanl pari ol'l lie scries.
Tiicsc tiills irradc into impure saiidslipiies. sliali's, and liniesloiies,
which arc nlicii ^daiicoiiil ic. I'rniii the y:iauc()iiite in tlic lull's and
jiloi'ilc, and citiicr ininerals
I'l-oiii the deciiiiipiisil i(pii <if tlic iu'iieipiis rucks, t here arises ii
inipiire scdiiiieiits, and tlic serpentine, i
<leri\ci|
f^cncral irrccii culnr \v
Tl
icsc rucks were iiii
liich chara<'leri/cs nearly the entire roriiialii)ii.
led al the head ul' l''uily mile (reck .jiisl above
I'laiikliii (Jidcli. Iielwccii I'uilyiiiilc (leek and Mission Creek uii
the ^'llkull, on Anicricjin (reek, and in the Lower Hainparts t'ruiii
l''ort llaiMliii euiisjderalil\ hewMid .Mynook (leek. (Sec " 'I'hc Haiii-
|iarl series," in ( hapli-r II.)
coMHTIoNS OF loltMATIoN.
he lirneons ruck oei
Ills In nian.N separate bodies, whicli arc ul'lcii
i)f iiiiiiiense size. In Ihesc in
the texlurc varies rruiii incdiiini-
euarsc tu \ cry tine ur aphanil ic. I'!\ cii in a siii.t;le b<idy it varies cuii-
siderably ; the tiner-^railicd |)ort ions near the borders ul'teii trrade into
liilT so .iria<tiiaily that no contact can be I'oiind in the field, and the dil-
eiM'iice belwcen lliusc rocks which lia\e truly iiiiicoiis characters and
those w Iiicli are tictrital I'aii be made on I only by aid <il' t he microscope.
In nearly e\ cry I'asc observed thcfliect of ii;iicuiis rock was conroriii-
ablc to tl verlyiiii; ami under ly in ;; sediments, and the line tiiiVs w liich
are composed entirely of diabasi<' iiialcrial yrailc into more assorted
sediiiieiils. such as impure si'iidstoiios and shales. 'I'hcse characters
show that I he iiiiicoiis rod
heels li'c
icciirrcd as siirraeo Mows, ami since Ihcse
ur abiiiidaiith at sucecssi\el\ liiu;her horizons, the vcilcanic
act I vii \ must have las
u Inch I here niu
ted U
roiisidcrable riod of time, diiriiii,'
.1 h
'cn sent (lilt sheets oi la\aof iiiimcnsc size
an<I cNtendiiiyovcr la rye areas. Diiriii;,' inlcr\ als between t he luiip-
tioiis there must Iia\e been periods ol' <'oiii|parative (piiet, when scdi-
iiienls aecuiiiiilalcd and life exislcil in the waters, for in a specimen
of u;la ui'oni I ic limestone seel ions of lisli tcet h ha\e been idciit ilied.
STUCt'Tl'KK .\.Mi COMl'ii-lilMN (i|.- UiiiKS.
Tlie igneous rock has a holoerystalline sliucliiie, and jicncrally an
ophit ic arraiiH:eincnt, all the components bciiij; well crystallized ami
inlcrlockiim'. The essential minerals arc plauioclasc, auiiite, and
iisiial!,\' olivine, often with much orthoclase. diallaize, and cpiartz.
Accessory minerals, which often beconie very iiiiportani, are horn-
blende, caleite, iiia;,Mietitc, ilnienile, and jiyrite. The honililende is
a deiM)in]t(>silioii proiliict of the aujritc, and the ealeilc, epidole, and
]tyrit(' are also si ndary. An e.xlremely eomiiion dccomposilion
product both of olivine and of aii;rile is serpenline, to which is due,
nl'I'HR.]
VOLCANIC (>l{ KI'ITSIVK KO( KS.
n
|iiiill.\ ill Icasl, I lie rock's jji'ccii color in the liclil. Tlic i|iiMrt/. i> mhiic-
I lilies sccoiiilary and soiiicl inics priinai'v . and occasimiallx iiici lasf. In
(|iiaiilit,v so as 1o form an essential I'oiistit iicni. In -.iiiiie ci-m'^ the
aiiiril<' is entirely a Itei'ed til t^rei'ii liorn blende, and I lieie results a linrn-
l)leiidi'-|ila;,doelase rock, which niiiilit lie styled epidiirite. Itse\ident
derivation from the typical dialiase, however, it^ Held relatinn-.. and
its occasional and reslrielcd occurrences seem to make such distinc'
live Jiaincs as t his .siiperlliious and inisleadiiiu;, and it is hesi. I lieie-
I'ore. lo consider all 1 liese rocks as phases nf a typical oli\ iiie-dialiase.
In consideration of liieir enormous luilk and extent, the dilTercnecs
are remarkably sli^dil.
.Mlhoimii even thi' rniest-j.''raiiii'd i;;neons rocks, which are aplia-
nit ic ill I he held, show . so far as oliserved. a holoerystalline si met lire
under the iiiicros<'ope, yet in till' tnlVs. which are coiiipiised iif the
same material, fray:ineiils of these line-^'rained holoerysialliiie rocks
urade into others which in places show a irronndmass uf cry|ilocrys-
tallinc ornoarl.v ^^lassy st riicl iirc, and t his i;romidiiiass contains small
pheiioerysts of the essential minerals which make up the dialiase.
Ohviolisly these are to he <'lassed as basalts rather than diabases,
and yet the.\' evidently represent only a slight textiiral and structural
ehanj;o from the liiie-i;raincil holiieryslalliiic rock. Specimens of this
altered l)asalt wi're not found in place, but it is probable that they
tints iir.
NoMi'.Mi.Arrm:.
The si met lire and composition of the <'oarser types of the iijiieoiis
rocks of the Hampart series, as well as their appearance in the liidd,
are those of a typical oliviiic-diariase; yet these rocks ;;rade into liner
phases, wliicli (ire aphanilic in the hand specimen, and pnibalilv into
rocks with cryiitocrystallinc ground mass. .Ml of these are midonbt-
eilly surface Hows. The 'rcrtiary basaltsof this same rcjiioii areofieii
fine-grained ami ain.vfiilaloidal, and also often holoerystalline and
ophitic, and in slrnctnre ami composition arc sometimes exactly like
the rocks of the Rampart series, the dilTereiice beintr that in the older
rocks the feldspar, auirite. olivine, anil other coiistit ueiils are more
<lecomposeil. ;ri\inn' a ficiieral ureeii color. whili> the Terliarv roidis
are nearly l)laek. iJoih, however, are esseni iaily holoerx sialline pla-
f,noi'lase-ailiiite-oli\ iiic rocks, with cryptocrystalliiie or glass> phases,
and both are surface Hows. ( )ri),nnall,\', therefore, they seem to have
been the same, 'i'liis intimate relal ioiiship is not expressed by the
terms diabase and basalt, and. as a eomiiromise between existiiifi
nomenclature and the actual facts of relationship, the terms basaltic
diabase for the Uampart series rocks and diabasic basalt for tiie
coarser poi't ions of the 'i'ertiary lavas are |>roposed. It is coming to
be reeogni/ed that the old terms of ])etrography are incapable of
expressing the true relationsliipof rocks, and n> more accurate system
J.H (;koi>, I'T .'{ Iti
w
•_*42 (ir.oLixiv 111" Tin: yruoN c.oiA) imsti;k;t, ai.aska.
has ,vi't licrti iulc.plf'l: hut llif li I'm' si'pi'ialiiiy: nirks as In tlioir
afic and Miijiin by pcciiliaiilics dI' Mriictiiiv and coiiiiinsilioii hasKimi"
1(V. In an i^rncoiis mass dillVicnccs in crv slalli/atinn alone will irivc
list' Id varifiirs wliirii nnflercxislinj,' rules of elasMiliealion will Iteiiiiig
let ijiiiii' cjill'erenl irroups.
TI'.IITI \l;^ li ASAI.TS.
Ai various points aloiit: liii' Viikoii and its ii-ilmtnries afe (lows of
basalt belonjriiiK (<i a <'oiiiparali\ ely receni ^;eoloj;ieal period.
.iiMTioN or rnr. rv.M.v am> i.r.\vi>.
Oiitlio Lewes, for |i> miles below I lie Jnnel ion willi llie j'elly, llio
rif^lil bank is a perpeiidieidar clilT of vesienlar brie basall, wliieli
forms i)ail ofa eompaiaii\cl\ level |plali'aii. risint:-on , .;im) feet abovn
the river. 'I'liis la\a Mow lias been noticed by !>awson, Uussell, and
Haves. |)r. Hayes ' ascribes it to two or more vents in llie immediati'
viciiiitv. These \cnts are siipposeil to be markccl by lii;;li liills, one-
about III miles ami the other 1 miles from l''ort Selkirk. One of these
hills is a synimel ileal cone, find is said to have on its smiiiiiit a small
lake, which probably occupies the crater. Accoriliu^r to \)\\ Daw-
Mon.'Mhislava field i.sc()iii|)osed of several superposed flows. Iiifortu-
nately no speeiiiieu of the rock was collected, so that no iletailed
dest'iiption of its nature can be i,dvcii ; but it is undoubtedly the same
as the basall at .Miles ('aii.\-on ami the other flows which will be
described,
MII.F.S ( ANYUN.
Orriirtriirr. — The rivei' eonnectinu- Lake .Marsh aud T,ake TiObargo,
which is that portion of the Lewes called Seventyinile Ki\'er. cuts
throujrli a How of basalt about midway lietwcen the two lakes. In
this llowihe river has cut a jrorure about I(mi feet wide ;iiid half a mile
lonu:, with JM ipemlicular basalt walls from tin to si • feet hi^di. This
is known as Miles ( aiiyon. Thiduirh this narrow cleft tiie whole vol-
ume of the river is forced, producini'; a torrent of excessive turblilouee
and rapidity, the water lieinj; arched up in the <'enter considerably
hiiilier than it is at the sides. .Midwa.\- between the two ends of the
canyon is a steep, circular basin, where the water eildies around rap-
idly before pluni.'in<j; au:ain down its narrow cliaiinel. jjidow the
canyon the stream liroadens, but is still rapid and full of obstruc-
tions for nearly two miles, at the eiiil ef which stretch conies a dan-
ifertms rapid nearly half a mile in leii,i;tli, know n as the A\'Iiili) Horse.
Here the banks are still of basalt. They are pei'jiendicular and
hardly more than If) or 20 feet hiKh (lifj. 15). Tiie channel is full of
pidjectiiifx rocks, so that the whole sui'face is bi'oken, foanlill;,^ and
' Expi'ditiim thniUKli tlii- Yiilccm di.strirt: Nat. Oi'mk. Miiit., Vol. IV, p. l.MI.
■' Ann Hi'iit Ocnl Nut. Hist. Survey Caniiilu. l«iT s.s. v.il III. Part I, p. llt'H.
I
VOI.CANK! OU KI'ITSlVn l;<X'KS.
•J! 3
tii>sili;;, ilixl ill tilt" cud is a iiaiiow uii|-;ri\ saiil In I lily :.'i) nr :iu Iccl,
\»ii|c. wliicli can lie .seen only at cxi rciiic>l\ li.w walcr. I'l'mn ijic
iicail I'l' the caii.\i'n Id iIic I'lml of llic W liilc l|iirsi> tin' di-iaiH'c. as
iiicaMiicd by Mr, <»i;il\lc,i i> j,- miles.
'I'lic basalt at this locality is .said not in extend l.-ir alio\ <• ..r lielow
llii' |ioinls iMcnlioiied. I' is made up of se\enil sii ssi\e shcits,
w liiidi sihiw licaulil'iil iMilmimar si met live. It is soinei imes mas>i\ e,
MOllK'tiinCH C.Mlemely scoliai'iolls or lileliliy. At llle W liite llorsi)
Ha] lids si rat died sills and ;;ra\ els lie on to)! oT I lie lia-~.ill at ,i liei:;lit
of Jll j'ccl. or mole alio\ e I lie lU'esent I'ivcr.
SIriirhiri iiiitl 'ihiiihiniIkiii.-- .\ s|)eeiiiieii of dark-lnow n \esniilar
rill. I."i. lill-alt, w
la\ji from tlic canyon is seen under t lie iiiicroscopc to eoiisisi eliiilly
ol" i)la};ioc]as('-f«'l(ls|)jir and olivine, Tlic feldspar is in narrow strips
with rajrjrcd cdircs and liordcrs. and the olivine in crystals which often
show rouylily iie\ai.'oiial outline, disseminated Ihidiitrhoiit, so -
t imes in cloudy masses and a.iraiii in liliers or shreds, is an aliiindaiiee
of rcddislidirown material, which, iinlced. i.'i\ es color to the seciion
and prolialily to the I'lxd. . This, from itsoccasioii.il association uilli
olivine, is prohalily Hci'penline stained with hematite and otiiei
nu'tallic o.xidcs. <^)uartz is iiresent in siii.ill amoiinl. .V s| iiiicn of
lilack crvstallinc basalt, with oiih occasional \er\ small vcsitdes. 1ms
'Ann. Ui'jit (-(•■nl. Nut, Uist, Sui-v.v Ciinacla. V..1 III. I'lii-I 1. j. MH
:lt'-
f*5'
ii
i
.'i-
■J I I i,r.nl,(i(i1 (IK TIIK VrKON (iOMi DISIRKT, ALASKA.
(•SM'llli:ill\ lllf silllir i'li,(liirlt'rislir> Jl-^ Illill ,|llsl (IcM'lillcil, cvci-pt lliat
III!' (•iy.|;il> lire ImiriT mimI ;ni ii|iliil i<' >l iilcl lll'i' iscillcli well showil.
Il also t'liiiliiiiis I'Diisicli'ialili' liliiiiili- .'iikI lji:iu:ii<'til('.
Cirii KI'N AMI SM'iil.KiiN ( lirP.K^.
<tciiiiriiiri.— ()u{\\\f\<ou (leek, at llii' head (if I'orlyiiiilo Crook.
Iiasall (>iilci()|» liclow I lie main tmks. a|i|iaiciil l.\ overlying' shales and
slialy (Mial scams, w liidi have liccn icrcnc(l lo the Mission < 'icck scries.
It is ncaily lilack and limly liolociyslallinc in I he hand specimen, and
1 1 111 I c njassix ('. li is said to oiilddii in places (i\ ci I h" w hole conn i ly
( I rained liy tlie lower part of I he creek and its 1 rilintaries, and on .Myers
l-'ork to I'orm the walls of a canyon I ("i feet in deptli.
(In Napoleon ('reek,.inst lielow t1n> nniin forks, is fonnd dark-hliie,
nearly hiaek basalt associated witli arenaceous limestones and ifi'its.
which likewise ha\ e liceii referred to the .\|ission (feck series. In
the \ icinity of t he basalt t lie limestone is nuirnKH'ized and apparently
somew hat dolomi/ed.
In the upper part of P'raiikliii (iulch Ini'fre Ixiwlders of finely crys-
tallinc basalt nr in the ^Travels, where they are known as "'jfold
rock" by the miners, sinc(> their considerable siieeilic ;iravity tends
to iiniko them sink to the bottom of the j^ravcls, where the ji<'l'l •■dso
aceiimidates.
Sfriicliin (i)iil (■(iiniinsiliitii. — .Speciniens e(>llect('(l from Chicken
Creek, Napoleon Creek, and Franklin (Jnlcli are all identical in
appearance, St riM't lire, and composition. I'lidor the niicrosco])0 the
rock appears to be rather coarse-^'raiiie(l holocrystalliiie. iind consi.sts
essentially of plau'ioclase, angite, and olivine. The pla^doclase is in
fresh, latli-sha|)e(l crystals, which have the ophitic arranjiemcnl ; the
aiij^ito is often considerably deconiiiosed, and in places has appar-
eiiMy ,viidde(l brown heniatitt* and nia^fiietito, and the olivine is some-
what allere(l aloii^ the mai'j;iiis and alonj; ci'acks to ureenisli-yellow
ser[)entiiie.
K'lVI KlK MdlNTMN .\NI> liri.uW.
A I' K'U I h( K Mnl N IAIN.
o,
'cfiirn iici mil.
hi.
I SI' ri III mil
-Oil the ^'llkon. .just below llie jinif
lion of the Koyiikiik, a perpendicular clitV rises directly from the
water to a heiuhl of jirobalily "tm or SOd feel. This is known as Koy-
iikiik Mountain, and is compose(l of basalt. On its smooth and nake(l
face two systems of colnmnar joinlin;,' are dexi'loped with diaf,'rain-
matic perfection. One set of .joints is nearly vertical, wliile another.
rlv Ir
iontal,
is at ri}j;ht anu;les to the lirst. The hori/.ontal
joints are closer to}jotli(>r than the others, so that while the lirst set
represents the ordinary colli in liar .joint iiiji; of lava Hows, the second is
like that oft "11 found in dikes. It is e\ ideiit that the hori/ontal joints
were formed subsc(|ueiit to tho \(,'rt ical ones, t ho lirst conlraction in
ri
(•ri nil 1
voi.rwic iiK Ki 1 i'si\ i; kim ks.
2 »->
fx
111!' I'liiilili;; l;i\ll lui\ill^ li;illll;ill\ | ii'i ii 1 1 jcri | iTi|i-U> i ir jii||it>. rii||o\\.
in;: llii' iliiiTiinii III' li'a>l n'>i.siiii , wliirli «,is |MT|i.iiiliriiliii' tn ilic
llppi'i' mill liivM'f I'jiri'^ III' ll Milium: -IhmM. whili-iiii riirllii-r I'lmi r.u'-
limi llic ilil'i'i'tinll III' li'iisl ii'vi-l.illrr I ;iirii' |ii'i |ii'iiil ini la i In llif
joint cfiH'ks ali'iNiily riuiiii'il. ami lliiis liDfi/iinlal .i«iiiil>, rluM-U >i.t
lii^rfllicr ami iiimiliii; rnmi uiii' viMiiral Joint to anolliir. \mto ilfvi-l-
opcd. A ronuli iliai.'ianiiiial ir >ki'li'li is ;;i\i'n ( li^'. hO. Inn mi tlif rlii)
ilxi'irtlif joinls ail' >liii\Mi iiMii'li Mini.' jiiainlN. iiiiil'oiiiily, ami hi^aii-
liriilly than ran lir sln.wii in tin. iljav.iiini. ami for rarli Joinl in ||||.
iliairi'ani I licri' an' a liiMnlri'd in tlmi'lilV ilsi-lf. 'i'lir imk Ci inning; I his
clilV is ol'irn ilark-lilno or f;ray. niassix f. ami tinrlv liMloriv-iailiiii'.
In otiiiT plari's it is poiphyi-itir or aniy;.'(laloiihil. Im-luili'il in ii aio
lary:r ri'jiuiiii'nls of allnrfij siMlinii-nls, such as i'ony:loini'i'alt's ami
sandstoi, s, uliiili liavr Ihtii lianlcni'il ami rcilili-niMl hy ihr liakiii;;
to wliii'li Ihi'y liaxf lirm sultjiTlfil. 'I'Im' la\a \M'atliir> alonir Joint
jilancs in places with uicat ra-
pidity, pnidncin^r ronipari riays
of various colors. In one scam
noted the central ]>art. adjacent
to ilic Joint, was a delicale hlne-
;^i'ay in color, ami was ijuilc piil-
venilelit. On lioth sides III' I liis
were ;;icaler ihieknesscs of yel-
low, oran;:c, and linally li^lil-
red clay, chan;;inf; to <lark-red, /i-~t-^7---A
these liritihl-colored clays liein;; ^! ' ip^/-/ ■' ' ' • ; /\
less thorollfiliiy decoin|ioseil. -^— ^— - -^. t .* ?? ;'~/ Tr^Tjf ~i ",/ , f A .
Tlie process seems to lie an oxj- - - — -
dation and leachinii. piodncinir '''"' '" "'"'•''••"" -ii"«in« ,j..imii.« ..r i««,it ,,n
Kiivukuk Mi.unl;iiii, 111! till' Vuk"ii.
the lirMliant-coloi'cd class, and
ultimalidy. liy lhiii'on;;h Icacliiiii:. the nearly while ones. Dr. \V. I''.
liilUdiraiid, of the Snr\ cy. examined some of ihe red cla,\ . and foil ml
the eoloriii;; material to lie liaioiiile. These clays ,ire ii>eil .as paints
l>y the Indians and are consideralily iiri/.cd, lieinu' carried lon^' dis-
laiices for tlie pni'pose of Iradiii^' to other Indians, 'i In- enlirely
decomposed and leached liliie-fii'ay clay, mixed with waler. was used
as a paini or whilewash for the inierior of ai'aliin at Niilaio. whert'
oiir parly slopped. This cabin lielonij:ed to a while I rader.
SI mil II ri mill i-niiiiKixiliini. — The only specimen of the Koytikiik
Moiinlain laxa which has lieen examined iiiicrosco,iically is. nnforlii-
nately, decomposed. .Mey:asco|iicall.\' it is dark-i^rcen and aiiiy;:da-
loidal, the am,\j;iliiles beiii;: partly i|iiarl/. and ejilcilc Inder tlio
microscope a larp: vosiclc, whose walls are lined witli serpentine, is
tilled with harite in interlockinj,' plates. Manysniidl ovoidal vesicles
are lined w ith .serpentine and (i lied with chlorite. There are comjiar-
atively lai'tfe |>heiiocrysis. which are now psemloinorphed liy calcite
M
/il-ll I : ■ h
J't-
I
24ll liDdl.oi.V i>|- Tin: MKdN i;<H.I) IUSTKICT. A1.A.-K \.
mill M'r|iriiiiiic, lull Wfi-t' |iiiili((iil.\ iirii' iijiily iiii\ inc. Tlii' .>tiiicl iii-e
of tin- u^■'lllll'llllfls^ i* a> if iiiiyiii,ill\ ciiiiiihim'i! ">f lii>liM'rv''tailiiif pJH-
•.'iiM'iji'><' .Mill .tin.'!'"'. 'I'Ik- .iiiiri'*' i- .•ilniijiliiiil jiiiii iiiii i;rciilly ili'ciiiii-
|«iM'i|, liiii till' iil.iL'ii'i'lasi- <M\>*tiil-« hiixr lii'fii i'i>|i!,'t<-i i| Ity pst'iiilo-
iii..r|ilis ..1' villi' 111 111 r mil. fiiil. "Iiiili !■• aiii a'-'iill> . in pari ai li-ast,
i^.iiiiipi. Till' im-k l-> i'\ iiii'.ii l.\ a ii'iU' iiliviiii' l(a>>all I'lHisiurralily
alii'i'i'il aiiil ili'-'iiiiipiiM'il.
Till' si-iiiiii iiiai'> lii'ils v liii'li ai'i' ii.i'Inili'il ill iln' KiiN iikiik Miiiiii-
taili ha.sall at''' I'Vpii^i'il a i-'li'irl ili^laili'i' Ih'Iiav iIh' iiniuiiiaiii in: iii-
pai'i.ii\ I'll utii!i'«\ iiilii'il •■iinililiun. 'I'hry rnnsisl rlii :iy uf iilark
-liali'^ ainl lini\Mi-\vi'aihi'i'in;r samlMlniii's. ami arr ri'lViTi'il liy i'M.
jtali 1(1 till niaiiiii' Mini'i'iii'. 'I'liry liaxi' aln-aily Ih'i-ii ili'M'iJIii'd
mull r 111! Iii'ail nl Niilal'i sainKluiii's. I''.\ 'i\ wlirii' hi'iv.'i'n tlic
Kiiyiikiik Miiiinlain ami lln' ili'lla of III" N'likiiii aii' Ti-i-tiaiy saml-
-inlii's. .sliali'>. ami I'liiiulnnii'iati's. fii'i|ni'iitly niin^xli-il «illi basallii'
I' -I- -. « liirli iifii'ii ^liii" li'aiilifiil I'lihiinnai- >trm'lmi'. Ai An\ik is
!ia>ali iiki' llial nl llir Kii.\ ilkilk .Mniintaiii. ami lii-ii' also tin- ili'i-uni-
|iiisi'i| /.^•nl"^ fiiriii'<li ri'il anil yrlluw paints In lln' nali\<'s. AIhIik i'l'S
I ivi'i- lii'liiw An\ik iiiiii'li liasall was nolt'il asMiriali-il wiili i',in;rlt>in-
I'lali'. wliii'li nia\ pussilily In- a Im-al ii\ it fui'iiialiun. AI llnlyl'i'i'ss
Missiiiii >pi'i'imi'ii^ iif i'iiii:;|iiiui'ialr>. samls'iini'. ami l(a>,ili wni' ccil-
li'i'l.'il. ;>i'l((« An.i/i'af'.k' llii'i-f aii' iid siiliil rucks, i«;'l mily llic Hal
ilcila ilcpiisits, aihl iliis I'liiilinncs in he llic case iiiilil SI. .Mii'liacl Is
I'l'aclicil i''riim ll,. liM-r, Iiuwi'MI-. a line of liilN. p' ilial>!.\' lia'-allic,
liia\ be Mill iiiiiiii _: I'liiii iiiiiuiislv liiini Amlrealski In M .Nlieliaei,
■-1 . Mil IIMI. l~l..\Mi.
(h'lirn iifi' iiiir! I/I III I'lil ili'firiiihuii. — Si. Michael Islaml isaimnl 7")
mil' .• nnrllicast nf tlie .\ pin ion, or nnriln'miiinsl imini li uf I lie \'iikiiii.
< Ml ii •iinateil tile I'liief Iraiiinu' pusi nf the Alaskan ( Dniiiiei'cial
'iiNpaii> ml tlie Xuiili .\nii'ii'an 'I'l ail lie.: ami 'rranspni'ialinn Coni-
p.inv . ail', it .^ I lieli'liil'c llie piiilll .'ll «liicli iieeail ■"leailiel'S are
linliiaileil anil river sleailieis l.iaileil villi sllp|ilies for llle coniilry lip
lln ^ iiknii. Xear it is aiiut iier islaml of .'liiiiiil the same si/e. calleil
Mewail Nlaml.
Michael Islam! ilsell i'. alimil s ,,v '.i mil
u iili li. all lniiii.;h I 111 he son I liwesl a Inn;' lonLrn*' .-' ii'ichcs oiii. makinir
in this ilireelinn l-"ior pi luiles. The whole of M.
Ill' total li'ii:r>li
.Michael anil m'i;;hliiirin;.' is!aiii|s ami of the ail.joinini: inainlaml
appears 111 he pnrclv volcanic. Near the I railiiiu: post the chief la\a
111!" w hii'li i- nil \ isihli. is a I loll I . 1 III
>f I he sea at liiL'li tiilo,
W here wasiieil cliaii h\ the water it is w rinkleil or ropy, show in_' it.
to lie the line upper snifai f a lava llnvv. These vvriiiklinL,'s .'ire
en rv I'll, imlieat in;; t lie ill reel imi of Iln.v . I ml the ili reel Inn < liiii show n
varies from place to plac.-, as it Irom eihlv inir cnrrcnls. .\liov e I Ins
! I I
V III
\OI.( \M(' <h; I iri-l\K Umcks
247
1m\ .•!<•" Ill" > a lii'il 111 \»iilill;iii| 111,1 Ifliii I, ell it'll \ i\l i i|iii|\ •m-.i|i,ic'i .ii|s
hiva. iii'iirl.v |iiiinii-c. Inn aN.i |i,iiil\ .iml in -.>i m^i-^ l.iri^ch dax .
\ iilcaiili' t><illlll^ all' oniiiiiirn. Iia\ iiiu a iiai'<l >lii'll lull nl' laiLri' |i<ii'i'>,
aii<l ai'i'iilial |iiiiliiiii wliicli is .on \(',>ii'ii|,'ii' a- in ]■!■ iii'ailx i'iii|iU il"
.■ninparat i\ '■!>■ I'l'i'-li; llii* |Miiliipn. 1im\\i'\ i-i-, i> nii.ii i|<'c'i>iii|mi'm'i| i.. u
snl'l. fell oi- liiav . Lilil l> ''lav. ici'aliilii: I Im' i1i'i'<iiii|mim'<I li.'isall al I\"i\ il
kill; .Miiiiiilain ami lul.iw. w iiicli i-. iis..,l 1p\ ili,. Inijiaiis r..i paini.
'I'liiTc ai'"' also iM'ca>l>inal Imw Mi't'. .il saiicl> i i" ami -lial'-. iiiiisih
iPliirulai'. all"! cil'ii'M a Inni iw inori' in rliaiin'li'i . lln'\ arc u<iii'ImI1\
j.'r'i'all\ ih'('uiii]iiiM'il, Inn >liip« n>p i-v i<l<'iii'i' ppI' IpaUiin;. Tlii'^ w anr-
laiil mail-rial lia> a li<'i;:lil nl' I'l'ipiii I'l lip .'n iVii . ami alupM' II cipiiu's a
Miliil >lii'<'l ipI' I'M rt'iiii'lv -.I'Mriai'i'iiii- lava "i in - lii'I lliirk; llii' tipji i<
lii'ailx iiiiiiMi'i'
1 I'lPMii's aiiaiii a i'la\> ' "ali'ilaH
i-|iiiMl. iiia<l<' ii|i I
.\lpii\ r I lii^ lav
aillviif liav:iii''iii> III' lava, ami llii-> li.Mr, wliiili
w licl'i' ipIi-^civ 111 1^ I ur ."p I'l'i'l I liii'k. i'ip|i>l il Mil "< iii'ai' till' |i<i-.| (In- 1ip|i
uC llii' i'^laml. vvliiili isalpiMil Jn I'l'i'l .-iIpipM' liiv'li liilr In hnlli ilir
niai:'rial ari- --I ii'kv ami ••iiliii' Ipiiiii'^. vv hii'li all .i |i|pi'al'
iN III' uali'l'laiil
lii'>li.
('nilirs.- Al "lilTi'i'i'iil ipuinl'Mpn lln i-laml i,iic' rinii'iir IiM' iinimiii
\\ li;i'li ari' n
iih :i I'i'vv |iiin>lri'il li'i'i alpipv i' 1 1
•r.il livil. IpiiI
iiipI ircalili III nn .i 'ircal ili-la iiri' liv i Inlri'ipiil ra^l In I hi' m'.iilv |ii'i I'li'l
Hal m-ss III' I III' ri'i' . 'I'Ih' imp>i i'ipn>|iii'iiinis ipiir i- a sliarp <'ip|ii' w liirli
hi a mis mil fai' rnnn I lir siiaiK lii-l vv.'iip SI. Mii'liarl ami Slew ail I--l;inp|.
Tlli-. is |ll!l pIppWII IPII llli'l nasi ^NIV ( liall Nn. V ;;'."i as "»!,.|i||,.||s
.Miiiinlain. ami is Uiinvvn in llip' n.ii i v I's ,|s ( Ihiu'I'MU 'I'll" sihimiiiI
•_'4>« lil;l>|,..l■^ cii nil; yiindv i.ipi.n iii>ri;iri, m.a^ka
nl'tlll-. l-iilllv .iImiIII IlililliM illw.M' llir -.il. ImiI jl iIm-s s<i .llllllpllv
lioiii I III' ll.il ill iis li.i^c ili.it It .ii)}!''!!!-?" Iroiii il lillli' iliNtaiK'i' lik«- a
liiiiiiiiliiiii 111 I ■Mii'-iilciiilili' »i/i' Aiiiit In T ••liiilH'liiM' ill iIh' itil#Tiiir of
llif i-.l:iliil I- -liinvii "11 llif -iiiri I iiii-.l >ill'\<\ i-liiil-1 .i> >l Vlii'liiici
Miiiiiiliiiii. IJiilli I lii'M' (•iiiniiini> iiinl I \Mi III lii-i« wliirli «iti' \ isilcij
iiii' liihi; I'si iiiiM \ iilciiMiii— (l''ii;.17.l < Mi I ln' lop iil' <'iirli is n circii-
liii liii*--iii -uriiiiiiiili'il liv il sti'i'|i iiii'U Will! iiiiil lilli'il wiih iin ii'rf;;iilai'
il'M I IllilSS III riiisl-li\ I'll llil« lllcis Till' lilMI 111 lIll'M' IlilW IdlTS is
r\ln!iirl> \ I'sji'iiljir. iii'iiiiy |iiiiiiii'i'; il i> liljirk nlnn rii">li iinij ml
111! ii\iiliii lull, iiinl il- siiii'iii'i' i- ul'ii'ii r"|>\ jiihI >liii:i:.\ . TIh' I'luii'i'
liiisiii I- 111'-! ■.liiiuMiiii III!' iii|i 111' Si. Mii-liiii-l Miiiiiiiiiiii Mi'|ilii'Ms
.Mull nlii ill. 11' Cliiiii'i'Mk. is il l:iii;i' iTiili'f liinki-n i|ii« li iiii"_'liliii'iy. su
I hill Mill' 111' I III' CI I IT' 's I 111 'SI '11 Is ;i >liiir|> iii|'.:i'. u liii'li iippciirs lilvi' il I'liiif
III il Hull' ilisiiiiii'i'.
'I'ln- pliiiii 1111111 wliii-li llicsi' I'liiiiii'iii-i'- risi' i- I'l'iHii L'l I 111. 'ill I'l'd
aliii\ I I III' s.'ii. iiinj il i'>iiiiivil\ iiiiiili' lip. iis >||iix\ II li\ iiiiiiii'iiMis si'c-
linlls iilnli- llii' slimi'. Ill' si lill ilii'ij ilsh. vvilll lilM'ls 111' lilii'l- i-laVfV
iMiili'i'iiil. Iti'iii-iil II I III' iisli. nil il li'\ I'l \\ il II I hi> si'il. is ill niaiiv |ila<':'S
\isillll' il IhmI III' l>ii«|i|i'l' ilil\ ullii'll si |iii|'.;|y slI^^iTcsIs ii'i' iU'liilll.
Till' i'\ iili'iii'i' sliiiW'^ iliiii ilii' hiNii siii'iiiii- I'iMili'il lii'iii'iii II ilii' siir-
I'jirc 111' llii' -.I'ii. iiinl il is s||iiii;_r|x piiiliiilili' lliiil ihi' Mili'iiiiiii's wiM'i-
Mlliliiillinr. rill- iMiMiii- liipML:iiipliv 111' Ilii- isljiiiil mil liiirdly In-
<'\pliiilH"l I'M'i'pl li\ llii' iii'liiiri 111' iiiiiriiii' I'lii ii'iils, iiiiil I'M'ii llii' riii-
ti'i- iM'iirllii' iiiiirks 111' iiiiir Ml' iiiisiun IIh' I'lniiii'iii'i's imu shmvii
an- iilil.N llii'lipsni v iiii'iiiiiM's. ihr ri's' liiiviiii; 1 i \i'iiil up liy
XMili'i'laiii ii>>li.
SIriiftilii ■mil ruin jin.silitill i.''/i'i'i/.- .\ spi'i'i im n iil' |li'>|| liiVii I'i'iilll
till' lnwi'sl Ijiiw nil llii' iinilli >ii|i' iil llii' Islallil is (link lifiiv III I'lilm-,
Willi i,M-i't'iiisli liiiinls. iiiiil is liiH'ly puniiis. I'liilcr llii' iiiii'iusi'iipi'.
lIllTC Jllc sri'll |llil|l\ pln'lllll'|-\ !.ls III' I'l'i'sll iili\ilH', "CIH'lillK Willi
pHHJ fiysliilliiir I'liiii
rii.'si
ill!' iiH'lii-i'il III il liu|i)cr\ siiilliiH' iiiasM
111' pljiL'iiii'lasi' iiiiil iiiiiiili'. Iiiillilii \ir\ lii'sli I'liinlil lull. Tlii pja^fin-
cliisi' is III lill II shiipcd i'i'\siiiK, iiinl ilii' iiiiirii,. ill iiiipi'i ii'i'i iTNslals
nr ii'1'i'L.'iiliii' ;;riiiiis. 'I'Ih' pliiy;iiic'liisi' liiilis ui'ii'ii liaM' ;i paiiilli'l
iii'i'iiiii:<'iii<'iii. sliiiw liii: Ili«> I'lVi'i'is III' liiiw . Ill ii;:iiiii iii'i' \s iiliniii i|i'liiiil<>
iil'ii'liliii Hill. 'I'lii- pull's nil' iiii'/iiliir in sliiipi'. iiiii| llicii' is nil ;;liiss
niiiiiii.v siiiiiiiliii \ iiiiiii'iiils. \lir.;iii'l 111' ill siiiiill II \ sliils I-. iiliiiniliini,
ilftni ilirlii.scil ill lllc iilivillr plii'lliii'l'\ sis
I'l llii I IIM l(l\ 1 11.
.Mr. I{. <i Mi'( iiiiiii'll ' Hull's iwii ilisiiiii'i |lii«s nl' liiisiili mi ilir I'm-
cllpiiii'. rill' lli'sl i~ aliiiiil |i mill's iiliii\i> ihi' niniii h nl' iln Kapiil
l{i\fr. iiiiil is Jl iliick slici'l iivci'lyliijf sliali-s, i|iiai-l/.ili's. 1111111111111'. anil
iiliicsdiiics. Tliis li.-isiili slniws 111) |i\ iili'iil I'liliiiiiiiiiisliiirliut'. Iliiiiit;li
IIk^IH' ill'*' rvitU'lH'i'S ol' ttilTfrclll llnw.s, I,, Irxllirt' lIlc im'k iTliHli'.s
1 Ann Hi'pi in'i.l .Nbi lllal siirvi'; innmlii, l>'»» "H. iiji rin l.tlli
fp^'
81'1'HH {
viii.cAMc OK I.I II st\ i; i;i" K
•.'4l>
I' ruin iiiiMlcralcly coarsi' aiiil :;iaiiiiliii' In liiu' uiann'il. ami in plai-i-s it
l)ci-iiiiif-. \ csiciil II' anil ainv '^"laliiiilal. I'lu' -.|H'i'iiMi'ii» i-i>11i'i-i.m| wimi-
(■iiin|M»i'il |ii'iiii-i|iall,\ III' ailixiti' ami <>||\ini'. nnIiIi snini' iiiai:ni'lili' ainl
I ilaliilViiins iiKii. ami wi'if aliiioNi i|i'v|imiIi. n\ |Mai.'inila»<-
\i'ai llii' <'ml 111' III!' IJaniliarl-- lia^all ts a;,Mili Iniiml ■■Miiyiii;;
>liali-. slalr-^, ami liini'-lniii'-.
" Ml 11. icn I.I!.
III. ( \\ llaM'>' mill'- llial ililiiiii; In- .|iiiii-m'\ almi'^ Mm- Wliili'
KiviM- lilai'U \ i'?<iriilar la\a. |iiiilialil\ nl' Tfllian a^rc «a> >iiii al a
iiiiniiii-r 111' idcalitii'-- lii'lwi'rii llic ^ iikmi ami llii' Si. l-'.llas Mminlaiii-.
ami llii> lava a|i|MMi-- In rnnii lnuail iiir^a- iiuilli uf llic ii|i|m'|- pail
1)1 lllr \\ hill' l.'ivci-.
I'l I i.s iiiv I If.
Di. li M I >aN\^iiii ' mili'^ lliai .'il i In' iiiiiiil li ul' II>hi!i' Itn ii mi i la-
I'i'lly ail' liliilT> 111' ilai'k-liiii« II lia'>all. uflcii aiii>;;ilaliiiilal m- M'^h-ii
lai , ami luiilaiiiiii;.' rliali'i'ilmiN , I'aliili'. ami /imiIIIc, Inn scarci-lv al all
('iililiniiar. I'*ai'l Iiit smii licasi I lie ■>aiiic i;i'iilii'j:ixl lia> imli'il liaNill^iii
llii' SlikiiH' \'all('>. ami Im'UM'iii ri'li"_'ra|ili (ii'i'k ami the 'ralillali
|{i\ IT I lii"^!' Iia>all'~ III I "111 iIm 1 I'liaiiin'l- ami hv itIh' aiiriri'iiiii> ;;rav ■
I'Is. Still lai'tlicr Mint li('a>i. near ilii' Miiilliriii pni'tinii i ,' l!i'itl>li
( "ililinliia, arc ullirr lia^all llnus. rnriiiiiiL' a iiniri' or li"-s innmM'ti'il
I'liaili ii'ai'liiiiL: 111 ' 111' lia-alN nl' \\'ii-.liiii'.^liMi, i •ri"^Mii. aiii| < alil'uriiia.
la'.^i Ml' "I , . iMni-niii.s vsn ~n:i ■ ii iti: "i ii\~m.i
III i'\ crv I'aM" « I II' I'l' inici'iix'Dpii' i'\aiiiiiial imi lia-- I ii iiiaili' ul i In'
lijl.sall (ami I lli> lia> 1 n ilnin' u il li x|ii'iiiiiiii» I inin \ ai niii^ Imalil ii's
I'l'diii .Mill's ( aiiviiii In M. Mii'liai'l. a ilislaiii'i' in a -.1 iai'.:lil liiii' nl' a
llnni-aml iiiili"-i lln ,i|ipiarain'i', .-.I nnl iiic ami cnniiiii'-itlnii aii'
I'l'iiiarkalily iiiiirnrni In i'mi-n cii'm' iIh' iih'', is an nliv iiii'-lia>all.
I'liiiipnM'd cs.M'iil iail> nl playini'laM'. aii;;ili', ami iili\ im-. ilii' >l iiir-
Uiri- i> u'l'iH'i'Jill.N liiii'lv Imlni'i's stalliin', ■"iiiiii'l iim"< l> iniiiy: ininlt'r-
ali'U inai'M' ami ;ii'aiiillai'. ami >iiim'llinrs ay;aiii scry liiii' u'laiin'il, '»>>
llial il i'» iitil al«a.\- i'as\ in ililTi'iiiil iaii' tin' ihiinI ii nciii iniin'ial.H
with llii' niii'i'iiM'iipi'. riii> last i> i-.pcciall\ lln' la-i' winri' llii' mi'k
is aiiiM-'ilaliiiilal ni M-sii'iilar, as it is apt In In- iicarllit' siiiiai-i' nl'
lliiws. Wlii'ii till' la\a is ill this latter I'ninlinnn ii is rs| iall> lialili'
In nviilal inn, iiliil llii' I'l iiiiial inii nl si.| pi.|ii nil', limniiiii-, ami ntlii'r
• Ifciiiiipiisiiinii pi'iiiliii'ls iilisi'iiri's in snini' il"'i;ri'i lli" m luiiial si rin-
Inn-. Ill pliii'i's u lii'i't- till inii'i'iisi'iipii' I'Miiniialiiiii was inaili' iinraiiN
sliii'lllll'lls I'ldlfi'lci;. III!' rni'k sriMlls In III' |. li'll* li'a 1 III ajiprall ■ « illi
tliDsi' wliirli lia.i' lii'cn siinlii'il.
.vnl 111 11 »s M IS.
All III'' liasalls uliii'li liaM' In m nliil liavi' mil hiiIn Mn- saiin'
strinliiri ami riunpnsil inn. Inii li.ivi' fxpi-rii'in'i'il ali nil tin' sann'
Kxi. .-.11111. II ilii-"iii<li ilii' N iiK"ii ili-irni Niii lii'.'c ,Miic . V. I l\ " I <'
'Aim Hi'i'i <l...l Nui lli»i. Mirv.H'iiiiiulii V.l 111. IT I lK»r «-. |i I'J.'I
•i,"!!! <ii;0I,O(iY Ml- Tlir. YIKON (iOI.K PISTKICI. AI,\SKA.
'«
slit'lil iiiiiMiiiiI 111 ilfcav ;iii<l <'ru>iiiii. Il is (■\i(|riil. llii'icrnic, that
lliiiii^li till' (linen-Ill lliiws .III' pruliably imi sliii'llx riiiilciii|ii)rai lis
tlii'V wiTi' Hill M'liaiiiliMJ iKpiii <piii' ainillii'i- l)\ a \t'r.\' Idiy- pciiud iif
p'oldiliral liiiif. As til ihcir iiufi', a limit is rslalilislii-il in mir iliiro-
tinii li\ till' fart that at lln' Koyiikiik .Momiiaiii, at tin- jiiiictiuii nf
till' K<i\iil>iiU Willi till' S iiknii, ihr liasalt lias limki'ii IlifiMi:_'li saml-
.stniH s anil sliali-s hI .Minri-iii' ayi', ami i-> tlhTi'iiiri- lali-rtliaii tin-si-
s(-iliiiii-iits. (Ill till' iitlii-r liaml. at tin- W liit.- Ilursi- Uapiils tin- lava
is i.M'i-laiii li> stralitii-il silt* ami l'ijimIs \ -.limt ilistai I'aitlii-r
iliiVMi till- liM-i- thi-si silts ami i;i.i\i-ls ii\i-rlii- -iMir clay nf u'lai-ial
iirij;iii. ami lliis aii'l "llirr i-\iili-i s alii'ail.\ i-iti-il ■•linw that lli'-y
wi-ii- Ciiiini-cl al'Irr tin- ii-ln-iit ul' tin- '.'laiii-r; ill this i-a.si'. llii-n-l'ui-i-,
till- basalt IS iiml<iiilili-ill\ |iii--(;iarial. Willi thi-^i' t«i> limits in iiiiiiil.
\M' iiia\ ioiiskIii tin- liasali as a « hull- u> \»- pinlialtly in lai'iiri- jiaft
I'liiii-iiii-. I>i'. hawsipii.' liciNN. i-r, nil ai-i-i)iiiii ipf ilii- hh-mliiii.' of tin-
Hfitish ( iiliimbia basalts vviih lakt- (it'pnsils « liirli liav Iktii ic-iVn-.-cl
111 till- Mi Ill', bi-lii'\i's tli,:t at li-ast the tirs; i-i-ii|>ti(iiis tcmk plai-i- in
this pi-i-iiiil, all 111 111;; Il I In- \ oli-atiir a^'i-m-ii-s may havi- cuni inin-il ai-tivi'
itiliilln- I'liiii-i-Mi-. Ill ( alitiiniia ami Oii-nnn. ai-cnnliuu to I'l-ofi'ssiif
I,r t mill'.- 1 1n- i;iral lava lluu s jinibably i-omiiiiiu-cil in In- iiiitpinii'il
at till' bi-Lriiiiiitm <>( the I'li'ici-m- i-pnrh. as -liuwn by thi' I'ai-t that
llii'si' lavas lii- iipiin i-rmli'il strata «il' .MiiM-.-nc aLTi-.
Mnilil'yiii;: till' iliii-i-t i-\ iili-iirr nliiaim-il III iiirai'l in tin- ai;i- <>( iln-
Alaskan basall by lln- siiiri^i'sl inns ih-riv i-d rroiii iii-iirhlinriti^' n-LMniis,
\\i- ina> say that tlii'sr IhnNs may liaM- bi-uiia in Alaska in lat"- Min-
i-i'iii-aiiil may lia\< n ai-lii-il into tin- i-ai'lii-r pai'l nl'ilii- ['h-isinri-iii'.
siiiic I III- 1 Til pi mils a I ilill'i-iriil liii-alil lis \M-ii- nut nri-i'ssaiil> ■•niiti-m-
liiirani'iilis. ami that tin- pi-i-iml ul' ^ii ali'sl aili\it\ was piist-^lini-i'in-.
Ill . -lii till- i-asi-s i-iii-il tin- (lows si>i-ni inlnm- bi-i-n ii-laii\i-ly small anil
local, ami nliiii. as -it tin- amiith nf tin- l*i'll.\- ami at >l. Mn liai'l, thi»
lax a st-i-iiis In ha\ I- bi-rii piMln-il I'iniii i-raii-is
arlivitv si-i'ius 111 111- ilisi iin-i I'liim tin- iiium
havi- laUi'ii plai'i' alniii^' lln- Alaskan I'l-niiisiila anil tin- Mi-iitiati
Islaiiils ami lailhi'i' iiilami alnii;; this saiin- asis in lln- ii-;;iiinsilraini<(l
rius pi-riiiil III' \ nlcaiiir
Ill I'i'iipl inns whii-h
by till- ('nii|
111- Kivi-r.
I'll
i-sc iiini'i- li-ii-lil niit lili-aKs si-cin
til III
lai';;i-l,\ amli-sitii-. The Mili-aiin- ash alrcaily imii'il is il iilyi'\i-
ili-nri- 111' i-iiinpaiai i\ i'l\ ri-i-i'iit Milranh- ;;rti\ii\ in tin- ii-yimi nt' tho
I jipi'i' Viikiiti, ami ai-i'iii'iliiiL: in I >i'. lla.\ I's this ash was pruliably pi-n-
iliu'i'd li\ an I 'I'll pi lull ill I III' III lit III- I'M pal t nl' t In- Si . I'.llas Mminlains,
iii-ar 1 III' sniin-i
111' I III- Kliiilaii 'jlarli'i'. This lasi-naimil ri'v:iiiii may
In- ciinsiili'i'i'il as tin- iimt Inasiiin i-ml nl' a /mii' nl' ri'i-i-nt vnh-anii-
iK'tixitv whii-li I'liiis ri'iim this i'i<;;iiiii thi'iiiiu^h lln' Alaskan I'l'iiinsiila.
•0|>. clt..p.!rB: MMniiMiTriii-i Hiy.il Sim- l'iiim.!ii. I'<lii>. V,.l. Vltl. -I'l- t. v 15.
!.\iii Jiitir. 8il .3dwirlii«. V-.l XXXII p. ITT.
Ex|ii-.Uli..ii 1I11..111/I1 lln- ^ iiK.1,1 .INti'i.f \ .1 il,'..K Milt- , V..I IV, |. ||». Ill :)i
(• H A PI' K l{ I V.
Mf)VK:*n:N rs IN iiii; i:Ai!iir>' < i;i>.i.
It is inloiuled In siuiiiiiai'i/i' mulci' the licailliiu i-'i\<'ii mIiuM' all
iiii|M)i ,aiil niovcnu'iils in liic rocks, iiiclii(iiii;r ii"t mily t'uliliin.' ainl
faiilliiif;, l)iil also iiiliTslilia! movciiiciils, iiroiliiciiii,' schislnsiiy ami
1ii(! liki'; iiiitiral inns dl' molten I'ocks, pidrliiciliLr ilikcs ,'iii<l la\ a slici'ts;
and the niiu'iat ions of inati'fiaN on tlic sni't'ai •■ lliioiii;li at iiio>.|iiii'fii!
aKui'C'ios, wiiicli ]»fo(liicc by iTosion ami ili'posit ion hilU aii<l vallcy.s
on tin- land and in'w i-ocks in tin- sea. Aiuon^c tlioc |H'occsscs, liow-
evt'i', ri'ijional ino\ cuh'mIs. pfodniMnir lli<> uplift or dcpri-sslon of ;;icat
ai'Oiis, iiikI IIh' folding: or faultinirof ;lii' snporficial rock--. ar(> prima-
rily important, sini'r it is lai'LTi'ly upon these that the minor .idjiisl-
liu'lits depend: and tl 'V will therefore lie eiiielly I'onsidered
SUMMARY OK GEOLOGICAL RECORDS IN TiIK KOCKS.
'I'lii' features ot' i;enerai importance- in the history ot' the roeu tor-
mat ions alotii.' the ^nild lielt in Al.iska an- --o far a-- impiMl'eet l\ Kihomi,
a^ follows:
'The fnndaiuenlal rociv of t le rcLiion i- a scliisto>e ^ratiite, and Ixin;,'
upon lliis is a thick seiies of schistose and often impure i|iiart/ile,
whose situation and pet ro^iraphical eha,r;ictcrs iiidicale a |)rolialile
derivation I'roiii I hi' irranile. The schj-.i- are also '.iraphit ie in place-,,
8iljii;estiiiLr the preseiu'c of oiiiaiiic life at this perioil. f.yiny- upon
theso qiiart/.ite-sidiist--. which lia\i'l>cen called tlic IJirch (feck set ies,
c'line thi(d^ lied> ot cr\ stalliiie inarhle inti'i'heddcd with • plait /.it c-
Bchists lia\ iim' much Ihc same cliaiacier> as lii'l'orc. luit irrailiiiLT into
inor<' Id^dily cryslalliiM' liornhlcndc and mica -chists. whicli f.irm
finallva larp' pari of tin' rocks. 'I'hcsc hornltlendc- and iinca-schists
ate often irii.philic, and ai'e evident 1\ deri\ed If (Mil ill! pine sediments.
Above tills scries id' marbles, schistose (piail/.iles. ;iiid hornlilcndi'-
aiid niica-scliists, which has been called the |''oitymile scries, comes u
ti]vu\ Ihickiicss of basic voleanic rocks, alleiiial iii.u willi tiill's and
impilie .scdilllelits. This lias been called the Uampart series. While
the r.infli Creek and Kmf \ mile .series arc hi«lily scliisiosc, the |{am-
pai't sorii'S is, on the whnle, massive, alliioimh geiiernll.\ Jointed and
locally becomin.u sclilolosc aloiiL; 'leliiiiie /ones. <»ii the whole, ho«-
e\er. tli<>re i- a marked contrast in de;;rec of meiamoipliisiu between
tills and the pre. i diii'; f<ii luat ioiis. In the I'ort \ mile tilid lUrch
(reck -.cricsarc some dio-itic and L;raniMc dikes w liicli lia\c bei'ii
/
//
;|i)l.(ili^ (II' Tin; YI'knN (li>|.i. KIsllJli I, AI-ASKA
trit'iitl,\ >lii'iii<-i| iiluii;: Willi llif iiii'lioiiii; rcick^; ;iliil lliiii' nvr i|ii;ulz
veins which art- ^'riuTiillv |iiir.illrl In Ihr "-cliiNlosil \ . ainl "hirh also
have siilTcrcil !_'ri'al shfariiiir. liisiiifs llic ^really shcaircl diki-s,
there are (Pllieis wliieh -hnw less anil less iiietaiiiorpliisiii, ainl liiially
SI line w lliell have lieeli elililel y II lia iVeel e( I liv ailN' «ly liaill ie ' I isl II ilia liee.
The iiiassi\e dikes, when Ihey iii in I'lnsr iirnxliiiilx In I he nmre m
less sellislnse mies, ill\ aiialilv slmw llieliisel\es In lie I he yiilin;;i'st,
ipC 1 he silies. I'hese sal lie yollliv'esl i|ike>. or ilikes iif I he same | ||-
liar l> |ies, are alsii rniiinl c'lii I in;; I he inek-. nl' liie i;ain|iail series.
.\liii\e the Niileaiiie links aiiil iin|iiii'e seilinieiils <>( the i{ain|iai't
series eiillie liinesluMes. shales, ami iieeasiulial eiilii^lonierales, whiill,
ll'iiln waul 'if klliiwlei|f,'e silllieieiit lor I heir ilill'ereiil iat imi, liave lieeii
^iiill|ieil lonelher as the 'rahkainl it series. 'I'liis series eonlaiiis in
(lilleieiit |iail> lo-sils. whieh iiiiliealelhal it Is in part ( 'arlioiiireioiis
ami in |iart l)e\oniaii; liiit I hese are liol iieeessarily the liinils ol' I he
ajie of Iheiiieks i iiel iiileil iimlerlliis elassi tieal ii ill. The 'rahkamlil,
series show > in .1 malkeil ilel,'lee less ileeii||||iosil inn ami met a nil ir| ill i SI II
than llie ltaiii|iai't •.erie>. ami the
ill'' liel Ween I he t uo.
a |iriilialile iinennl'iiiinil \ eNisl-
.\lio\ <> III)
ihkaililll series eoliies I he .Mission (leek series, vvliieli
is, ill jial't at lea--t. (leta Us. .'iinl is inaile iijior Itlaek eaieaieoiis
or rehls|iathie >liales. inijiiire thin lieihlcil liineslinie. yiii_\ samlstoiie,
ami eoiiL'liimerale .'^eaiiis nl' impure inal anil oliseiire plaiil remains
are iil'leli I'oliml. Inn oeeasiolial I'ossiN show the serie.s to ha\e lieell
larv'i'l.N a marine formal ion. .\t the liase is a eoiitrioinerate, whieh
lesis iinionfiiiiiialily on ilie Itampart series ami l-'oityinile si'iies,
.iiiil roiilaiiis pelildes ilerived flolii these nicks.
■ Miove the .Mission ("reck scries eoilies a Ltreaf thickness of iiiassi\('
eoni,'|omeiates. uilh coarse ;,'iits jiiid some saiid.N. aitiillai'coiis liiiie-
ese rocks contain aliiiinlant plant
stone ami iminire
>hal
Til
remain^ ;llii| occasional freshwater fauna, on the e\ idelice supplied
li\ which ihev are relernd to the Koceiie
Thei
V are no marine los-
sils or other e\ii|elice of lii.il ine colldil iollS. The ciili;;loini'rates coll-
t.'iill pel Ides of the liaillpai't series. l'"orl \ mile series, liirch (reek
seiiis, and of \arioiiis oilier sodiiiicntary and ijfiieous rocks. Tl
IIS
lileal thickness of flesh-WJlter lieds has lieell called the Keiiai serii
The Tahkamlit series, Mission (.'reck scrio and the |\ci
all show .'ilioiit the •^.inic .imoiini of il\ nan
lai series
-t iirliance. t here In ini.r
app..i'entl\
rv ureal iincoiiformit \ >eparaliliu them from one
another, and all h.'i\ iii^ heeii folded toHciln
Sometimes these lolds
■n. Mini soini'iiineM cliiseh c III
ate t;<>iitlc, soiiietiincs liiiiad and
lircsid and \eiiical. (iwini^io this fohlliij! Ilieri' is local .juintliiit,
lull all tin rocks have lieeii pniclicallv iiiialTccted li\ rc^rional
■•Ileal iiii;.
'I'hc Weds oM'ilyiiii; the Kcinil miljes are few and scull ered. <»n i he
upper p.iil of Mi'sioii Creek arc partially consoliduti'd, iicarl.v lioij-
m
38
II or; II, A I MiKvi
r
V
Saclion on LihB A A
KiGH^fTN^H ANNU'Vl HFPORT r'AP'"
^■»,
g^r.Mi Villi, .1,
V
.'/^
V
/■ On,
>^W
f
\
-v
I.'
>.
.."•i^'
^ "mm
A ,. .-■
J'
' Ullilis -r:,''
Poncu^iHf, DO*L 1 ' I X S -
i ^ .■,i..ii7iisirv_tf„,^
1MB A *
!• . ,1 S r a I e
!*l>l HU ]
(IKiil.oi.li \|. MM'
2a3
/nlilal ii.Mu'liMMiiiil"'-. ;iliil LTlil- i;in\ llii; |il,'iiit ii-mimiIin, uIiicIi ;i|i|hm|'
It) n nil 'si mild w ith I MM Is I. II till' I 'nil' II I li III' ;i III I Mjii'Uili/li' All I In si-
M'iliiiii'iil> ail' |p|iiliiilil_\ liii'jil ai'iMiiiiiilalinio ill laUi's 111' liiiuiiil i'\li'iii.
Till iM' III! I III' Mai'kfti/.ii'. « liii'li wi'ii' i-\aiiiiiii'i| li\ Mi Nii-< (iiiiiill. have
Im'cii i'i'I'i'I'I'i'iI Ii,\ Sir Will ia III I >a\\ ••nil, nil 1 1 \ iilciu t 1 1||. ilmij w Incli
lliry I'Diilaiii. Ill (III- l.araiiiii' (l-'nrt riiiuii u'i'iiii|>. m' Kui'i-in-. nt' I'liili'il
Stairs ;ri'ii|iii,'i>t> ami nt' tlii'» ri'|iiiit 1; lint iIh'Ti' In >Iill r f,ir i h,
.siisjtii'iiiii that tlii-y iiia,\ |iiii|iitIv Ih' a»siL.'iic(| tu ilir Niiiiiiiii'. TIh'sc
lii'ils ill!' M'|iaiatfil li,\ a lindiiiiiiil iiiii'iiiilnriiiil \ fnnri llii' iiinli'iU
iii^r Kfiiai M'lii'S, lifiii:.' milv ;.'i'iil|\ Iilti'il. while tlmsi' uf lln- ixi'iiai
nil' sliafplv fiildfil. At llif {.ihmt Kaiiijiaiis an- i'iii-.s.li(.i|i|i'il sainl-
stiiiii's with I'lissil li'iivcs. riiiii's. ami I'la^'ini'iiK nf wimmI TIh'm' Iii'i|>
arc jinilialily I'lini'i'iii'. I''iiiall,\ rmiii' llir l'li'i>l in' ami ri'i-i'til
hilts ami iiiiiM'ls. u liii'li an- srallcn-il ail nxi'i- I lie I'liiiiit ly as a ii'suli
ol' ili'jiiisil iiiii ill I III' ;.'iral laki'saml lixi'is.
GEOl.OOICAI. MAP
It was tlii)i|i:lit Iti'sl til |iiit ii|iiin a maji i^i'i- I'l \\\\IIIiili(>
ilil'iiriiialioli I'lilii'i'ti'il riiiii'rniiiiu' I lii' ;ri'ii|ii:ry nl thai |Hiiiiiiii ut' t Iit>
(,'()li| lii'lt ill Alaska wliiili was I'xaiiiiinii in llif >iiiiiiiii'i nf I-^'.mI.
Siiiiii' lii'silal imi was IVll in iloiiii.' I his mi ai-i'Diiiii nl' ilir rxliriin-lv
liM'a;;i'i' aiiuiiiiit ti( ilala a\ ailalih'. < )ii I hi' ntlii'i' ha ml. I'l'i'taiii lirnail
H(>i)li>f;irai I'ai'ts wliirli \m'ii' rli-arly priiNi'il li\ mir iii\ isi i;.r;,| i,,;,^ ,.,,|||,|
not lie a|p|iri'iMali'il rimii wrillni i|i'si'ri|itiiiii-. almii'.
Ill iii'iliT III iiiaki' I'li'ar llir atiiiiiiiil nf data rrinii vvhii'li dilVi'ii'iil
jiiirt inns III' llii' iMa|i urii' iniisl iinli'd. an iiiii'uliii'rd lia^i' ina|i is pii'-
wnli'd. (Sfc i'l. .\\.\l.\.| I >n this nia|i till- iiiiiii'-. w hii'li liaM' I n
t ra\i'li'il liy iilisi'i'Vi'i's who have n;adi' iioli'S ciiiii'i'inini; the ;;i'iiliii;y
are iiidiealed l>y eolored lines. The red eolDiinj; shows the tra\erse
liiiide liy the I'liited states (H'olii;;ieal Survey party in I he siliiiiner of
]s;iii. |''or a ;;r(>at part nf tiie dislame traversed only extreinely
liiirried and iinperl'eel r miiaissanee eoiild lie made, while ii rlaiii
olher paiis, sueli as the {'"ortyniile and llinh (reek iiiinin;,^ di-.! rieis,
iiiiiie earefnl thoimh still hurried work was done. The lirowii line
shows the route lit' a hut lied reeonnaissanee liy .Mr. |{. (t. .Me( onnell. of
the (aiiadian t ieoloLrieal SurM-y. 'i'lie yellow line is t he rniile t ra\ -
er.sed liy .Mr. W. < »L'il\ ie, of the ( aiiadiaii i Jeoloirieal SiirMv, and eoii-
eel'liin^t this I ;i Mi' Oy;il\ie lia-> made a few \ ery lirief notes. The
blue lint- is the unite i.iveled liy Dr. liayes, who aeeompanied l.ieii-
It'iiant Sehwall 1 m ms trip aloiiL' the While and ( opper ri\ers.
Tlio fjreeii line ■- lie route folliiwed li\ l.leUleliaill .Mlell on the
Taiiana and KoyiiKiik ri\eis. •oneerniny: whiih he has made one or
two rather \a:,'in' ^eolii;rieal notes. The oraiiire line represents a
I'oiii ineerniii;; wliieli some infuniiiit ion was oliiaiiied liy pros-
peeiors, the information :ii\in by whom, liowe\er. is of doiilitfnl
value, since liieir diseriminat ion of roeks is iioi alwa\s aei'iiiaie.
I s
IMAGE EVALUATION
TEST TARGET (MT-3)
1.0
I.I
Ik
I* I.
UUu
2.5
1^ I
2.0
11-25 i 1.4
1.6
Photographic
Sciences
Corporation
33 WEST MAIN STHET
WfBSTfr N.Y. )45ao
(716)173.4503
Jk^
^,^>
Ill .
II
OKOLOGY OF THE YUKON GOLD DISTRICT, ALAl^KA.
Tlic iiil'i)iin;iti(iii iiidiciilcd jihovc is all that is aetually available
coiiccriiiii^' the ^fcoldijy of t lio rcifioii inapiicd, and on tliis basis the
nia[) has Ijccii constiMictod. Alonu- tlic I'onlcs (hdinoafod tlio observa-
tions arc always r(»ugli and sonictiiiics niircliablo, and in llio intor-
vciiiiii^ coiiMli'y llic frool((Lry, as in<licat('d on tlio luaj), is pur(dy a
niattci' ol" inference. It is not. e\|iecto(l, tliorefoi'c, thaf the map is
any more tlian the I'ndost apinoxiniation to tin; ti'iUli; yet it is believed
that it will serve a pui-pose until more careful work is done, and,
indeeil, iiuiy serve as the basis for such work.
In the cross section accompanying: tlic map everythinj; is jien(>ral-
i/.ed. 'I'lie repi'cscntation of the relative ihickiu'sses of the dilTcrent
formations has not been attempted, sii these ai-e not dellnitely
kuown, and unconformities are not shown. < )nly the general st met ur(>
and tho succession of the dilTorent series as roufrhly divided, and ns
explained in the text, is ,t;iveii.
The suinniit of the Yukon ueajiticlinc is shown on the left side of
the section, and this chaiiffcs into a shallow geosj'iicline on tlie right
side. Just northeasi of tlie Yukon the continuation of the ^laTninoth
.Mountains foi'ms a scarp of youiijicr rocks facing tlie axis of the anti-
cline. The country shown in the left of the section and in the corre-
sponding area on the nui]) is represented ;.s being entirely of granite,
since '.].■' only notes availal)le are tliose of Lieutenant Allen, who
describes granite along the Tanana. It is the belief of the writer,
however, that this structure as I'epi'cscnted is i)robably incorrect, and
that younger rocks will eventually be found overlj'ing the granite
neai- the Tanana or ininic(liately to the southwest of it, and that these
younger rocks are on the southwest lind) of th(> Yukon geanticline.
There ai'e as vet, however, no data for this belief.
DIVISION OF ROCKS ACCORDING TO DYNAMIC DISTURBANCES.
!«
All the rock formations u'uy be roughly divided into three chief
groups, according td the degree of dynamic disturbaiu-e which they
have undergone. The first gi'oup consists of the mori^ or less schistose
rocks, beginning with the fundamental granite and ending with the
Kampart series; the second group consists of tho uushoared but often
highly folded ro(;ks, beginning with tho Tahkaudit series and ending
witli tlie Konai series; the third group consists of tho nearly horizon-
tal and oidy partly consolidated sediments, beginning wit Ii the Twel ve-
nule and Poi'cupine River beds and ending with tho icccnt gravels.
These great groups are separated by great uiu'onformities, and
althougli minor unconformities undoulMedly exist withiji tlio groups
themselves, yel the\' do not apjiear to be of nearly the s;"ue im-
portance.
39
1
1
\l
n
,!
H
1
i
j
i
If
1
1i
ii
US GEOLOGICAL SURVEY
MAf UK A KJKTION OF THE VTIKOiSr CiOLlJ HF.LT .WD ADJACEI
NOTES ll.WK BEEN
Suale .,{ Mile!.
fpf^^
EIGHTEENTH ANNUAL REPORT PART 111 PLATE XXXIX.
)LD HKLT AXl) ADJACENT REG10N8, SHOWIXci LINKS ALONG WHICH -IKOLOUIC
Nf)TKS HAVE BEEN MADE
Uuale .<r Uiles
12(1 I40
IB(I IBO
H
4
1' 'r 3!
! i 1
m '] 1
it
f
n
8I'LI1H 1
MOVEMKNT8 IN THE r.AliTMS iRTST.
25.')
HISTORY OF ROCKS TO END OK RAMPART SERIES.
BIRCH CKKEK AND KdKTYMII.K MIKIKS.
Tho fiif'ts of observation which Iimm' hccii iiivcn in ilic suiniiLiry,
t()ji;ollior witli minor ones jfivcii in llic (icsciipt i(in> nl' ilic idck I'oimim-
tions, may be interprote<l as follows:
Tli<( Cirst event which we cmii disiMMri is the cxihisui'c Io ciiisixc
a),f('nci«'s of a fiindainojital uianilc As a result of this llnri' ai'i-iiiiiu-
lalcil a thick and widesprcail (Icimsit of sandstone, ol'tcu iiiipurc from
tlii> admixlui'c of olhcf i^fanitic niatciiai. 'riic iiiicikm' of •ria|iliitc
in tliosc no\v-mc1amoi'iilioscd sediments siii^'u'ests tliei)resen if life
ibifinj; their ile|)osiii()ii. Alio\(> these siindstones were laiii (hiwn
thicjc beds of limestone alteiiiat ini; wit h sandstones and more imjinie
sedimenls, often liij;iiiy earl)onaceoiis. 'J'lie tliiekest beds of linie-
stono were deposited immediately alio\-e the samlslones. while in the
upper iiai'l of tlie series impnr<' (let rital rocks became nioi'c al>niidanl .
All these sodimeids seem to lie npon one another, so t'ai' as yet
observed, conformably; and the accumulation of so j,'reat a thiekm'ss
of conformable strata ma.v be taken to i-cpicsent a loni;' pci'iod of
nearly utuform conditions. 'I'lie t ransition of the j'.irch (reek quartz-
ifes to the Fortymile marbl<>s nia,\' represent ,1,'eiicral depression and
frequent immunity from land se(limeiits, and the increasing' airioniit
of impure sediments at the top of the l'"ortymile sei'ies may indicate
rcelevation.
This long period of ([uiet, with oid,v uniform and widespicad cruslal
movemont.s, was brought Io a close by a series of great disturlianecs,
which lasLcd for a long while, '{'he earliest numifestal ion of these
disturbances appears Io have been the intrusion of molten roelc from
below, fornung dikes cutting tlie sedimenlaries. At about Ihesame
time movements in the crust brought the rocks under great strain,
which was relieved by the slipping of grain u])oii grain, and of one
laj"er on another along bedding planes and other lines ot' weakness,
and finally by the product i<in of great folds. It is iirohaltlc that at
this time liegan the closely compressed series of folds along an east-
west axis which are shown on the map (PI. XXXIX) as alTeeting these
older rocivs, especially along Fort.vmile Creek, and farther east. Tho
internal structure of the rocks was changed, not only by the move-
ment of grain upon grain, but often l)y tiie crushing of nniierals or
their i uigation along Iho lino of least resistance. As a consefpien<'0
of ])re.-jure and aceonipan,\ing metamoi'phic innneuecs new minerals
were formed: limestone be<'ame marble or dolonnte; carbonaceous
rock becnmi! graphitic; and from iiTii)ur<' sediments crystals of ndca,
hornblende, garnet, opidote, and rarer minerals were <leveloped. 'I'he
formation of tho schists from .sediments has already been well de-
scribeil, and the events need not l)e repeated. The pi'c.ssure appears
'i\
•_'5G <iKOLOOY OK TIIK YUKON OOI.D DISTKICT, ALASKA.
to liav:' lii'cii so jrfMit'ial anil ur/idiial lliat no nniforni regional planes
i>r slicarinn -^vas iiidnci'd : hut I lie vcnicnls I'oUowcil wlialcvcr planes
«(■;•• loi-iliy liie weal- est, and tliese appear 1o have been K<'ii'"ii'II.V
tliehe(l(lin;>l)lanes. The eviilenee ol" this isctiiedy found in Die l'"orfy-
inile disli'iel, wliere tlie seliislosity is everywhere ivjiuhir and parallel
to Ihe true iieildin;;'. the lattei' heinu shown by the alternation of
niarhle with sell! sis. tlioiiirh it is shown also iii Ihe l.irch ("reek dislriet,
wlier(> the seliistosily, so far as ohservcd, seems to he a {food index of
struct nie and of the relations of t he dill'erent schistose series to one
another. It thus lia|)pens that the schists on I'^orlyniih' ('re(d< and
to tluM-ast alonjr the Yukon have a general east-west, strike — cor-
respctudinj; to the east-west folding shown liy the succession of foruui-
tion.s^but a vai-yiufi: ili[i. On P.irch Creek, however, the foldinj^ is
niori' };;entle, as seen on the map.
\"ei'y early in the period of dist urbanct' narrow (juartz veins wci'C
formed in all the rocks '■liercM-r tlie dynamic stresses i^roduoed open
cracks or /.ones of weakness, which naturally becanH> water channels.
WluM'c no previous special .system of planes of weakness e.Niste(l, the
channcds thus produced by dynamic stress wcu'e relati\'ely few, as is
11u> case in the nuissive marble of the Fortynule sei'ies. In the more
definitely layei'ed .sedimentary rocks, liowevor, such as the ([uartzitos
of tlw r.ii'ch Creek sei'ies, and es[)ecially the impure schists of the
Fortymile series, the pressure-producing' movement along the weak
bedding phines made tln'm still more available as water channels.
Therefore, i)i the basal granite and in tlie nuissive marbles, the quartz
veins ai'e relativtdy few, but they are abundant in the more definitely
layered rocks. As nuiy be infcrrinl from what has been said, lliey
ari> usually conformable to the schistosity of the rock.s in wliich they
occui', but occasionally they are found cutting iicross the la.vers.
'I'he.se veins are genei'ally narrow antl noiipersistent, ami are often
merely elongated lenses, as if foi'ming in cracks left by the si>reading
ajiart of layers under stress.
It has already been mentioned that these schists are cut by ii series
of dikes of dill'erent ages, of which the successively younger show less
ami less shearing. Tlr ■ is an evidence that the devolo[)inent of
schistosity was very gradual, and much other evidence confirms this
conclusion. By the continuance of tlie shearing process, features
which were developeil as the conseiiiuMice of the lirsti movement were
altered or oei^asionally obliterated. The earliest dikes become .schis-
tose find the quartz veins became stretched or juilled into shreds;
and metamorphic minerals, such as garnet, were crushed and eloii-
gateil along new slipiiiiig planes.
fJ.V.AIl'AHT SKRIES.
Near the end of the long period of disturbance \V(>re eru])tions of
basaltic lavaover a great area: sheets of vast thickness and extent
were poured out. 31uch of this lava must have been poured out in
'ill
siiiui.) MOVr.MKNTS IN IIIK r.MMIIs CHI-I'. 2.'7
till' ^c.-i. I'lir llii' ^liccl.s wi'i'c .iiipaic'iil ly iimnriliali-lv cciv-cn-d ii|i liv
I litis Mini lit 111 T M'llilllcllts. 'rill'-.c clVll-inlls uciMIIIi'il lc'| li-.l 1 ( ■> 1 1 y lor it
Iciiiii'l iiiii'. .iiiil ill llii' iii1i'r\als licl WITH lliciii si'iliinfiils ai-fiiiniilalccl,
sdiiirliiiics imhii|mpsc(| ciil iri'ly III' volcanic iiialcrial. I ml iriacjiially iiinw-
iiiL;' |iiirci-, ri>riiiiimiiii|purcsaiii|s!iiiics. slialc-.. and liiiic-liiiic^. In I hcsc
|)ci'ic»ls. also, soinc lilV cvislcil. as is siinwn liy lisji icclli (iisco\ci-ci|
iiiicroscopiciiUy in mn' of ilic specimens ol' alicicd ^:laiii'oiiil ic liiiic-
sioncs. Owinn' 1o 1 lie i;i'cal I liii-kiicss of .some ol' I he lava slici-ts, liic
texiiii-e III' ilie rocU is fieiiei'ally I'oiiiparal ivcly coarso, so lliat llie
coarse \ai'iel ies have lieeji descrilied as d ia hase a nd the « lioje scries
lias lieeii cliai'acleii/.e(| as liasall ic dialiasc; I liese iiriieoiis rocUs and
asscieialed sedimc'lltaries lia\e lieeli i;r(mped toirelller Under t he head
of the l{aiii[)ai-l series.
'I'lie liaiiipai't series is only locally schislose. an<l forms a slnnii;
coiilrasl to the imdei'lyiiii;' hiirhly iiietamoiphic l-diiymilc scries. It
appears, t lieri'l'oi'c, that the strains prodiicinu shearini;- were mostly
spent before the iiiit iation of \(ilcaiiic a<'t i\ iiy. or they ma> lia\ e heen
relie\ed liy it; hill t he prod net ion of t he Joi III inn a lid local shearinii
may he ascrilie(l to the last elVccis of t his reijional sii'ain. Xomcal
niiconlurmity has l)e('ii ohsei'vi'd helween the T'orlymile scries and
tlie ]{ain|iart series; and alt liouiih it is prohalile from the iniiniicrof
their f(n"iialion that some dcn'rcc of unconformity exists, yc-l ii seems
that the movcnicnt which prodiiccij the cast-wi'st folds in the older
ro(d;s did not culminate until al'tci' the end of the formal ion of iln'
I'aiiiliart series, since on l''oriymilc ('re(d< and elseuheiv tile latlci'
seems to l;a\'e heen atl'ecled 1p\' this svslcni of fojdini;'.
HISTORY I-'ROIVI RAMPART SERIES TO END OF KENAI SERIES.
.Vflerlhe formal ion of tin' liamparl si'ries caiiie i he deposit ion uf
thick heels of liiiieslolies, shales, ami occasional coni^iomcrates. uhich
ha\ c heen calleil 1 he Tahkandit series. This incliKles rocks laid dou n
in l)e\(iiiian and in C'arhonil'ennis lime, ami may iiidinh' rocks oldi^r
or yomm'er than these periods. In the ]H-olial)le Devonian strata
below .Myiiook Creek smiie plant reiiiains were found in the shales
assiH'ialed with limestones, indicat in;;' occasional |)ro.\imity lo land.
On the ^■||kllll heiwecn Mission Ci'eek and Circle City. Carboniferous
fossils occur ill limestone interbeddecl uilh coniilomcrale u hose pel i-
bh's are mostly of chert of \arious brii;ht colors, and espcciall.\' of a
deep ureen. like the eherls which ha\f formed in llie rocks of the
Hamparl series. These I'oniilinneralcs siiy^'cst laml in llie imiiieiliale
vicinity, aii<l it is therefore probable t hat at tins lime the ■Jampart
series fonneil ill |)lacesa land mass. The Tahkandit series appears
to be separated frinii the Kamparl scries by a iireal iineinilormily. for
altluuiffh no act ual I'oulacl was obscr\-ed. yet t here was seen no ureal
(le^'rce (if nncuiiforinity between the Tahkandit and the ovcrlyini;'
Mission Ci k series, the two beiii;; folded tonelher and in aboiil the
IS (iEuL. 1-T 3 17
:ii\l
iKoi.odv or riii; nikmn f;i)i.i> iPivn.'icr, ai.aska.
•Mini' i|i':;'nT: w in
Ir till' .Mis-.i(iil ( liM'k >c-lirs III \,lliiills |il;iiT
\\,l«
•II 111 yi"-\ ii|Miii t he l!iiiii|paii --c'
ill IIIMlki'il lllll'iinrill'lllil \ . 'I'lir
« ii?< |irul);ilil,\ , linw c
\ IT. a >li.L;lil iiiiciinrciniiil \ lii'tuci'ii I lie 'I'aliUiiiiilii
ami llii' Mi^siciii deck si-rics, as lia> alicail.v Ihtm sialcil. Un ihr
illulr. l|(i\Vr\rl', lln' 'I'allk
scllo \M
i-f laii
alikaiiilil, I 111' .Mi»iiiii Crrck ami llic Kniai
iiic n|Miii llii' iiilii'i'. iimli'i' ('iiiii|iai'al i\ <'l,\ iini-
riinii ciiiKliliiiiiN ami willi iioyrral (list iirliaiircs: .suit .scfinslhal llir
loiii;- licriixl III' ilisi iiiliaiicr."- wliii'li lii'uaii uilli the sli('ariii,ir. roiiliiiu.
ami iiil I'lisiiMi III' iliki's III llii' l''iiil \iiiiir series ami oilier rucks ciiilfd
u II li I lie ell II >lc 11 1 111 I lie \ iileallie Idi
ks 1)1 1 lie liaiiiiiarl scrii
Tile rucks III' ihe 'ralikamlll series arc marine scclliiiciils. wiili neca-
iiiiii plain reiiialiis ami cniii^liiiiieralcs siiiiyesl liii; llttural <ii' I'resli-
ualel ccilll
lillnlis. 'I'lie n\ erl\ inn' .Mlssjllll (reck lucks are llll|llll'c
si'i||iiieiii>. v^lili maii\ la\er> iil' iiii|iiirc coal ami aliiiii<laiii jilaiit
ii'iiiaiiis; \i
I tl
il> series cuiilaiiis marine I'lissils. su llial we iiia\ enn-
clmlc I liai I lie nicks were laiil ilmvii In I lie xichiil y of I lie la ml, siiinc-
liiiicsln llie sea ami siimetlnio In Iresli \\alci': anil rnnii the usual
\er\ tine iiiaiii nf the material In the rucks, cnisinii ami <le|iiisii Imi
[iriilialily went mi with mily a \fy\ imiderate (lei;ree nt' rajjidity. (tn
the (ither liami, the Kenai si , ics which overlies the .Mission (reck
sciles. ^Iiiiu?. Iiy Its aliiinilanl plant reiiialiis aiul occasiunal IVesii-
waiei la una ami , he cut ire absence of marine organisms that I lie rucks
Were fonneil ciiiiivlv ill t'rcsli water. This series is of ifi'cal tiilckiiess.
iml the plant remains I'uiiml at tl
ittoni arc apparently the same
as those I'oiiml at the lop, ami all Imllcati an Kocen
e a,i;c
It
ilciii. tlH'rcFore. that these rocks ai'cumiilatccl at a period of \cry
rapid erosion ami deposit Ion. ami t his cuiii'liision Is coiilirmed hy t he
naliire of the roi'ks themselves, which are chlelly massive coii;;lum-
crali's and coarse jirits. 'i'licsc coii.i;lumcralcs contain pehlilcs deiiv cil
I'l'oni the l'"f>rt VIII lie. Ihe IJircli Creek, and the Uampart series, as well
;raiilte and ol h
r lyiieoiis and scdlnieiitary rocks.
(out last I nu' the evidence oll'ered hy the 'rahkijmlil series vv Itli that
of the Mission Creek series. v\ e may assiinie a .;;ciieral eh'vatlun
lictwi'cn till' ilepusitluii of the I'ormer and of the latter, so that fresli-
waler lieds and evidences of land proximity hecunie iiiiich mure
alinndaiit. .\t the end of Ihe dcpuslllun uf the .Mission Creek scries
there must have liccii .-i marked cicvalion and the forniatlon of a
liluh land mass which was v lolcntly attacked hy erosion and rapidly
dea'i'adcd. The material thus removed v»as laid down In hudles of
fresh water, formlni;' an immense thickness ol' sediments in a coni-
parativ'elv short time, p'rum the cumpusltiuii uf these scdlmcnls. it
Mpjicars that the 1 Jam pari series funned an I m purl ant part i>\' the land
mass, while all the rucks ulder than this series must alsu have liecii
e.\po.sed, ami i)i'uljaljly rucks bdoiiyiiig to vuiin.u'cr foniiatiuiis.
MoVr.MKNIS IN Tin; I-.AIMII > CK'I-I.
2.-)^
THE POST-KENAI REVOLUTION.
A I I 111' I'll! I (iT Ki'iiai I iiiH' I lici'i- uiTi' iihpv c'iiiciil> "I ;:rcai iiii|HiiIaiii-i'
III 1 lie c-ni>1 111' I lie I'.-irl li, I III' iiiii>l ri'iiiarUalili' i-i'-ul! nl w liirli ua'^ a
S('l'ir> III' Mi'\nii'> III' \ a>l ilillli'll-iiill-. u lllrli lia\ I' \ I'lX Inlii;' null liui'-l
jiMil Mini lira^t a\i'>. i M' i Iitm' I'uliN l hr liol kimu ii lia» lici-ii nai 1
till' Niikiiii u'caiil ii'lini'. Almii; llir a\i> nl' iIun I'uIiI IIh' riiiiilaiin'iilal
i;raiiili' I'Xli'iuN ri'iiiii I In- Taiiaiia almiu' I In' \ ilk mi anil I'i'llv as lar a--
Ihi' |)i'aM' IJiM'i'. a ilislaiii'i' uf iii'arl> >!"' iiiili'^ in a ^li'aii;lil liiii',
OVcl'lylim lllis iiiailili' In tilr null lli'a>l ami Ik llli' Milllliui'^! I'lillii'
(|iiai'l/.ili'-sctiisls and iiiarMcs liclniiiiini;' In 1 lie llii'di ( "ri'rU ami I'mi \
mill' --I'l'ii's. anil l.\ iiii; ninin \\\vm' ajraiii, at a iiiuri' I'l'iimli' ilisiann' rimn
I lie uraiiii ir a\i>. an' si ill > unnui'i' rm-ks. < tiir kiinu Inlu'i' nl' i Ih' siir-
cession 1)1' si ra I a mi I lie siuil Ii\m'--I -iilr nl' ' lii' I'nlil ili'|ii'iii|> niainlv mi
tile nnlcs niaili' li.\ I'r. Ilaxi's in his liavcrsi' ainn;.;- llii' W'liili' ami
('iippi'i' i'i\('i's.' (>ii till' iinrllii'asl siiii" of till' fill. 1, hiiui'S IT. tlii'siii'-
I'l'ssinll lias lici'li innl'c rari'l'llllv iilis('i'\ I'll, anil lia^ ln'Cll ili'snijn'd ill
I III' iiii'i'i'iliim' pay'i's. Till' siiccfssinii 111' rm'iiialimis mi Imi h siilrs ni'
ihi' i^raiiilii' bi'll is lliai lyiilcal of an aiil iclinal riiluv. Ii i- pinlialili-
lliai lllis ucaiilii'linc iliniinislii's rapiillx' ni'ai-llii' pmai wlii'ii' il nils
llii' ^■llkml at liii' l.nvM'i' Kaiiipai'is. ami linally ilii's mil.
.\s a ui'iii'i'al iiili', ilir ilip III' lilt' rni-ks nil lintli siili's 111' ! Ill' L;i'anl i-
I'liiii' isawa.N rrniii I In' .i;raiii1 if axis. 'I'liis is I'spi'cially well shown in
llu' rni'inalimis wliirh an' ymiiiui'i- than lln' Kainparl sitIcs. sincH
Ihcsi' lia\i' lii'i'ii lillli' 111' mil at all alVci-ti'il li.\ llir I'asl -wrsl -I ri'iiil-
in^- rnlds wliifh arc I'.vhiliiii'il li\ lln' IJaniparl ami uMit nirks. 'riic
\-nmi,i;'('i rocks, llicn'rnrc, shnw in llicir si riici nn' simply ami clearly
ilic cITi'cis III' llic posl-Kcnai rcMilnlimi. On llic ri^i'ht siilc of Ihc
Viikmi. hcUvci'ii i''iirt\ mile I'nsi ami Circle Ciiy. Ihesc yoiin;;'er scries
are cxposcil in sliai'j niitains in wiiich the ircml of Ihc si rata cor-
respomls with llial of the raiin'c. ami the dip appears lo he nnifornily
In ihe nnrtheasl. smneliines at a cmiiiiaral ively m'lil le anulc soinc-
tiliies licarl.\ verlical.
iicsiilcs the ^'llkon iicanticliiic there arc iirolialilx' oilier ureal folds
havinu Ihc same .ncneral Ireml. The exisieiicc nf a -cnsyneline lyiiii;-
iinnicdialely northeast of Ihe Viikmi i;cani ielinc and liavini; the same
liclieral trend is indicalcd on ihe map of Ihe pild hell, hut this rcinv-
selilatimi of sirilclnrc n'sis on very sli-hl inforinal ion.
NEOCENE MOVEMEN'i'S.
Ill Ihe period siiecccdin.u' the posl-l\i'liai I'l'Vohit ion Ihc Lncater
pari of .Maska seems to have lieeii land. Alon.i; Ihc l.nwer Viikmi. in
the vieinily ni Niilaln. are marine limcsi s and impure sandsinncs.
'I'licsc are rip|ilc-niarkcil and cniss-licdilcd. and i lam plain rema.ins.
'}
•_'(!() (ll.iil.iKiV t>l' llir. VI'KON (i(iMi IIISIIMCT. ALASKA.
iiinl Mil' llicrc'l'dn' |iriilpMlily .1 lillnr.il rdriiuil inn. In I lir rcyii.ii I'iiil Iht
Moll lii';t>l iIhtc is :in aliM'lii'c "T iiiiii'iiii' scilinii-nl>, liiil tln'i'c .-irc
(M'iMNiiiMiil rrcsli-wiiiiT ImmIs. inilii'iitirii:- II laml surfju-f w iih nniMi'inns
Ijikcs. wlijcli may In- I'i'rcriol In llic sji pi'iiml as tlic inaiinc saml-
slipiH's a I Nulalip. hiii'lML' lliis |i(ii("l \\\i- la ml sui lacf was itimIimI ami
the axiscil' ihc ^■||klln ;;i-anl idinc was unrn ijnw n. cNiiosinu- ilic(]|il
rcicks in a Inciail Im'Ii with I he ;;faiii'al I'cci'ssiun nl'llic yiinriizci' I'cii'Mia-
I ions. 'I'lic Mirt'ac'c <>r iildi'!- I'ipcks lii'caMM' in process (if lirm' snincilhcil
<|ou II ami li'M'lril, anil llii' slopes I aine n'cnl le. so llial 1lie ri\cis
iiieamiered I Ip'oiiyli iiioail. shallow \alleys. The imperreei plateau
thus ]i|-o(lllee(| has lieell ealleil I he Ilileli')!' IMalea II. ami si ieleliesn\ ri'
llie ;,'ri>atei' pari of .Maska ami !>iitish ( olninhia. l''roiii an eleNaled
poiiil of view, il apii"ars like a ueiilly iimliilal iiii; plain, from whieli
rise hills ami inoiinla'ns of no i;real heiulil . in I his plain ha\ e lieen
(•III Ihepr-'seiil deep ri\cr \ alleys, as a eoiisi'ipii'iiee ol' ihe Neocene
elovalioii. NNJilcli will lie releried lo laler on.
MAMMiilH \l(i|\l.\l.\S.
I'rom i-'orlyiiiile ( 'ri'id^ lolhe Kaiidik K'i\er there is. on the liyhl
side of the ^■||kon. a rani;c ot' tall sierras risiiii;- from :;.niHi to ."1,0011
feet al)o\(' the ri\er. wliieh (lowsi'lose to tiieir liase; on the left side
ol' the ri\er is the usual hroad. iii'arly lc\el plateau at an cle\;ition of
several hum I red feet. I'roiii I he top of t his plaleall t here is ;i U' IJeral
level ohsel'Valile lictweeli the tops of the peaks on the liiiiit si(|eiif
the ri\'i'r. yet these peaks are so sharp as to present a yreat <'ontrast.
with the ^reiitle topourapliy of the ]plaleaii I'oiinlry. 'I'he raii;;e has a
ii'eiieral norlhwcsl trend, ( iirrespomljni;- with that oltlie rixcr: il w;is
(irsi noticed in'ar {''ortymile Creek, ami from there cont iniioiisly to
the is'amlik. lie low t he Kamlik I he V iikoii t urns to the east ami t he
raii.iic st ill continuing' its mn-lhwi'si t rend, di\ erues from thi'ri\ci'
and is lost siu'ht of. i'"rom the aliiimlaiice of the remains of i he fossil
elephant ormanimolh in tliisrenion il is proposed to call thisiaiiue
tlie. Mamniol h Moiinlains. I''ii;'. is is a \ lew (if t ne liiuhest peak iioled
ill ihisranu'e. which has already lieeii iiaiiuMl Kathiil .Mountain, and
issitiiateil a sliinM distance alioNc t he Kandik.
I'riMH t he ri\('r these imninlaiiis appear as a ri(l,u:e of nearl,\' u 11 i form
ma.ximiiin heiirht, hut carved into low. serrated peaks of hare i'o(dv,
usually dark red in c(i|(ir, with lar,i;e liands of linlit li'rax . which are
more resistant to w eat hcriiiL;', ami so form jiinnacles. The yray lielts
maintain a nniforni posiiion for miles aloii.u' the side of t he ridu'c. and
tlicrel'ore the roidis lia\e a strike conformiiifj; to the trend of tiie
inoiiiitains. naimdy. northwest and soiiiheast. Ihdow l'"ortymile post,
a short distance the dip appears to he uniformly to the northeast at
an aii.u'le of ->> or imn'c.
Near the international lioiindary these imMintaiiis were (diiiihed hy
rrof. I. ('. Kiissell.' and were found to he about o.dnii feet ahoNc Ihe
' .\.it..>Mii tiw Siirliiii' iJ,.,,l,,iry .if .Vla.-kii Bull (i.-..l S..... Ain.Ti.:i. V..I I. j. rui
TV
M'tldl.)
NK<>( i;nk mii\ i;mi;\|s.
Ml
ii\ir. Al till' ])l;icc \i>iicil ihccrcsl ol' llir ran;.'!' i'iiii>isi(.il ,,f rcmi'
piiri. c'iirlliv liiiicsloiic ill iMMily vcitiriil slfai.i. -iiikiiiu' ''"iirmiiialilv
w iili t lii> ti'i'iiil III' I III' niiiiiiiiaiiiN.
'rill- Tall III! I lie i> (Plir (pT I lie si ri.aiii> u liicli llnws l ||i(ini;li I he Maiii-
iniiili Miiiiiilaiii"-, i'iiii'rin_ ilif ^ iiKnii mi ilic iiL;lii ^Idc. \|i. \\ .
(»i:il\i<'' i'i'|inriN ilial llir mi'lo almi:; iliis ii\ ct aii' daik sliali's ci\ I'l -
lain !>>' rnn'-,uraiiii'ii I'uiiiildiiicralo ami iiiiclcilaiii li\ ;;rayisli j'alcu.
/(lie lillloldlM'S.
I'l'iiiM this inrdniiatiiiii ii a|i|ii'ai'>> iliai llii' Maiaiiinlli raiiur i.'^m-
|iiisim| 111 till' yciuiiuiT iiic-k-. ami. a> >ctii un ihc iiia|i, lln' imiiii,iaiii-<
l\ iiiu clcisi' 1(1 till' ^'ukllll arc rnniicil ul'llial |iiiil imi df ilir vdiiiiijcr
I kswiiii-li lio inn liali'l\ aii.iai'i'iil in llir una w 1 ' llic ..i.S'i-
l*'ni. l>^, - Kjitlinl .Alniiiitiiin. !\r:iniin"f!i Kaiiei'.
scrii-s all' I'liic'lly r\|Hi-.cMl. In ullicr Wdii|>. llii'--i' iiidiiiilaiii> a|i|M'ar
111 111' an rriisidii M-arp dl' t lie \ iniimiT riirk^ larini; t lie hIiIit series
svliieli lie nearer ilie a\i> nl' llie ^ nkmi i:eaiil irliiie.
i>i;ainai.1': s^^■|■|••.^l.
The ^'nkllll lti\ er lldws aldii;; ihe Iddl III' tile Ma mil mill .Miniiitain--,
uhieli |iriilial>ly eiiiisiiliite, as alreailv saiil. a si-ar|) iiC I'l'iisinn. The
|iarallelisiii nf the ii\ei- In the avis 111' I'lililiiie ami its iid-itiini al the
I'lidt 111' the miiinilaiii searp siiu'jesl thai il iiia\ lie p/i-iarily ilne In
the I'dhlini;'. il' this is the case it is pinhalile that the iiriuinal liiienl'
drainage uas parallel In the present mie. Init was lieLrmi I'art her ^din h-
' Ann. li.-pl ll.'..l. Xal lli-t Surv.x lalKi.lM, l-.-> .-i. Vol IV. p K-[)
I
l'(;-_» (;i;ni,(i(;v <ii' Till; vi'Kox (joi.d ihs'I'kk'T, ai.aska.
UC-.I. iicMiii- IIh- ii\i-.iir 1 lie uiMlll ii-lilic, Miun Jlllcl- I Iji' I'oiiipill i<ili ipC
llic lojil. ■A\\i\ lli.il uilli liliH' il liiip\'il In IIm' llipfllicjisl. rollipwili;; Mil'
siMl|i iri:|i|i' li; lliii II "-si il' I lie ,\ I'llimcr lucks. Ill lllis com
lion llic (lilTciciicc licl wccii Ihc si/col' I he liiliiil.ir,\ si renins dm IIic
llipll licasi iiImI nil llic siplll liucsl, siilc ipT I lie N'ukiPli .lliilin' lllis lii'il
III list I PC I II p| CI I. 'I 'I II ISC I.I I I lie siPlll llVM'sl siili' .'ire ipT cullsiilcrjillle si/e,
ICMcliiliu; IIS iiillcli ;is Inn miles in ;| si IMi^lll line liiieU riniii I lie \' Ilk nil,
ullilenll llic nnllllcnsl llic\ ,lle, sn I'.l r iis i III | icl lecl I \ k ni PU M . liillch
sJMiilcr J III I s I ini II cr. .is slmu n mi I lie c\isl iMfr iiiii|is. ( 'niicei-iiiny' I lie
Icnulli III' Ihc 'i'iil.'iiiliic. wliicli is iPlie III' llie l;ir;icsl nl' I lie .sifejiiiis
cniniiiir in I'r I lie nnillnasi nlmi^r lliis lieli. \\eli;i\e inrnrnnil inn
iVnin llic sil|-\e\ nC Mr. ();,'il\ie. 'I'liis slreilin liciiils uiily nlinill "in
miles in .1 slr;ii;:lil line auiiy I'mni I he N'liknii, .-imiI, ;is seen nn ihi'
nni|p. llic iliv iilc IpcIuccii I he ^ iiknll .'linl llic rnrell{pilie lies rcm.'irlwl
1pI\ clnsc In I he rnrmer riMT. 'I'liis ille(|U;llily liel WCCII Ihc si/.c ;inil
lelml h III' I he ri\ els nil I III I un siiles III' I he \' II knll slinu s I he c \ isl dice
III' I he iiiniinl.'iin scai|p nil 1 he imrl heasi ; .iinlvcl il iiinsi lie rcniem-
Ipcrcil thai llic\ ;i'i\e nn ilear iilea nl' Ihc aeliial a liril |pI iiess nl' Ihe
scarp, si n'c llic\ are assislint,' in Ihc |irncess nl' weariiii; back, ami
I heir \ alii \ s are alreaily i-iil i|ee|)ly ami licail eniisiileraldy imrl hcasl
nl' I he I'l'Liil wall III' I lie mnlllllailis.
il is pipssilple llial I he 'ranaiia ami smne nl her si reams alsn mini
lialc'l, lii.e I he ^'llklp|l, as a eip|isei|iieiiec nl' lllis | pipsI -K cmii rnhliliL;;
\cl SIP llltle is kmiuii as In Ihe i^cnlo^iy nl' I hese rccii)lis llial niily a
sii,L;i;'esl inn call he iiiailc
m-.(i(i:nk i:m:\'.\thi\.
1
.]!
i
a.
: 1?
f ■!
. : &
i
if
1 . k
14
• ■
li^
The recdl'ijs nl' aiieiclll t;enln;^ical I iliies are sn in lleli oIlSCIM'ed ami
allei'eil that ue can nriliiiaiil> Irace clearly mily llmse e\eiils w hich
were III' Ihe \ cry i;rea I esl iiii|inrlaiice, while Ihe inliinr mics remain
llllklinwii nr can al liesi he nlily cnii jeel iired. .\s mnderii L;eip|(Pi;ica 1
lime is ap|irnMchei|. ImweM'r, Ihe r ids liecnine more Miimeripiis
ami I heir mcaiiini; is more e\ ideiil . I'll lis. nl' I he e\ enls in Ihe cnnr
mniis leni:lli of lime which elapsed lielwecn Ihe lirsl scdimeiils nn Ihe
lia.sal u'l'iinile and I he lieninniiin; nl' I he Tcri iary we lia\ e heen a Me in
nITeronly I he loiii;hesl sketch. < )( 'I'erl iary I line, hnwc\ er, inileh more
delail can lie pri'scnied, and Ihe ceoloLrieal record inerea.ses in perfec-
I inn lip In ihe prescnl day, when we may see Ihe prncesses nl' cllMlli;e
cnilli; nn liel'nre iplll' eye.s.
( *nc III' I he means liy w hich we arc enaliled III I rai'c earl II iiin\ emcnis
in ninre recelil Jienlnuical lillics is pliy.slo;j:i-aphic i|e\ elopmcnl . We
lia\c alreadx seen linw Ihe cmnparalively Icxel inlerinr phileau willi
iis aiicicnl liroad, shallow valleys, and moiinlains ;fi'eai ly reduced liy
cripsiipii. poinis lo I he si alii lily of the land for a Imii;' period siil»se(|iieiii
In the Keriai re\ nlul ion. dnrillfr W iliell period at mospherie I'olces weie
al work. In Ihe same manner Ihc deep, eaiiMiiidike \alle\s in which
-Ct )ll( I
Ni:(li km; MuVKMlAIS.
263
HI: .'•t'ii
■-, il
I lie I in 'SI '11 1 si I CM MS IlliW I I'll 111 III M llrriilpll ,'11 II I liilr^ riilll i lllli'il r|i>\ il-
I lull III' I hr In III I ;il I III' rml I'l I Ills I II 'I'll II I III' stiiliilii \ . Till' I' II I till :^ nf
I lli'si' ilri'li \ ;llli'> s mIiHiu; llli' lilli's iil' I lii' nlil s|imiiis|| i||-:iiii,-|'^r Innk
phici'. ii\ I'l' I III' will ill' III' Al.-iskil, Ml Till' :is U I II iw II, ,11 111 i-iili 111- 1\ plailii'il
iiiiU li\ sii|i|)i)siMi; ,'i ui 'I II Til I I'li'V ,'il iiiii u III I'll Inw i-ii'il I III- mil Ills III' l In-
ii\ ITS, Mini SI I I in mil; III .iliniil rapiil ilri'iii'iiiim nf I In- ili-,iiii:iL;i' I'li.iiiiii'ls;
;illil silU'c llii'sc \iillllj;i'l' \,illr\s .III' iil'li'li si'xrral lillliijn'il I'ril i|i'i'|i,
I lie iii'W ('( nil li lion III' alVaiis iiiiisl li'i\ i' lasti'ij I'lii' a Imr,: i iiiii'
/'. r II 1(1 III I h rill inn. W c ma V Ih'IIi'M' I lial I liis i'|i'\ al imi limk plan'
ill la 1 1' Miiii'i'iii' III' I'arlv I'll 'IH' I iiiii's. I'lir I lir mai-iiH' \|iiii'i'iii' saiiil-
siniii's ill I III' \ iriiiil V III' \ iilalii ami laKi' lii'iN sin-h as i In- 'I'u rl \ !■
mile lii'ijs al llii' lii'ail nl' .Missimi ('ri'i'k liavi' ln'iii lillnl ami Im-ally
I'lilili'il, wliili' \ iiilliiii'i' ili'piisils an- s|i^|il|\ 111- mil al all ilisi iiilii'il.
Miii'i'iiM'i'. I III' 'i'wi'iv I'liiilr lii'ils slanil al an i'li'\ al imi anil in a pusii mii
uilli I'l'^^anl II' llii' prrsrnl liraiiiaLii' wliirli slmus a Ihiil: priiml I'l'
iTiisiiiii sini'i' lai'Mslrinr i-unilil imis ui-n- possilili-. ami iIh' mann''
saiiilsliiii"s an' i|i'i'pl\ I'liI iiiln liy 1 In' I.'i\m-I' N' nknn. sn ihala lai'L;i'
pari III' 1 1 nisiiiii III' I III' i-i\ it \ alli'\ lias la ki'ii plai-i' sim-i- I lii-ir ili-p
iisil iiiii ami i'l('\ al inn inln a pari nl I In- la ml mass, (in I lir ul lii-r liaml.
1 lii'sr \ allr.\ s i'\isti'i| ill prai'i ii'ally I licir pii'si'iil i-ninlil inn pri'viniisiu
I III' ( JIai'ial pi'i'inil. I'lir I lie I'V iilci is a I mm Ian I I lial I In- Inlii's ul' i In'
I 'I in li III' ran iilarii'i' i npii'il I In' \ alli'>s nl' I In- I'ppi'i- N' iiknii am' nl In-i-
sli'cain.s ulicn llir.\ ucri' in prarl ical l,\ lln' sail mlilinii as miw,
ami nil I III' ri'lrral nl' I lie ulai'ii'r lakrs urri' rnrim-il. u liirli iinw iii-i-npy
pnrliniis nl' ll Ill \alli'.\s wliirli liaM' Ih-i'Ii ilainiii.'i! nr s|i^||lly
ilcpri'ssi'il. .
\'iilviiiiir iiiliiili/. Al alinill. till' saiiii' i;i'iii'ial pi'iiml i-a inp-
liniisol' Itasall rrniii iiiaii\ sralli'i'cil siinn-i's. 'I'lii'si' Mnws ui-n- limii.-il
ill si/c, ami wrri' usually rrniii xnli'anii- \i-iils. ll lias aln-ailv I n
siltiursli'il rrniii inili'pcmli'lil i'\ iili'iiri- llial I lii-sr rriipl imis Innk plai-f
llinslh ill I'linci'Mc llllic, u llii'lM\as illsii III!' pcriml nl' I 111' ai'l i M' i Inw n
I'lillint;' III' llii' prcsclil \alli'\s. Sniiii' nl' lllc llnws appi'iir In lia\i'
ilammi'il up llir \ alleys, as al IIh' J 'linn nl' llir I 'i'l I \ ami tin- L.'wi's
ami al M ilrs ( aiivnii. Iii'l wi'rn l.akr l.i'liarm- ami l.aki- Marsli. m-i ai
III,- inni-linll 111' I 111' I 'i'l I \ I 111' xallry nl' I In- Lrwrs has lii'i'll i'\i'a \ alnl
:;iiu 111- liMi I'l 'I'! Iicluw I lie liasall plalcan siiii'i' 1 1 IViisinii nl' Ilir la\ a.
Till' I'liiirsr 111' llic l.nucr \iiknii lii'lwi'cii llii' Knyiikilk ami lln-sra
may III' ilili' I ll Iilili'ialimi nl' IIh' aiirii'iil \alli'\ li\a la\a llnu ;
hill ill Ilir Kn\ iikiik .Miiiiiiiaiii llii' liasall lias, siiliscipii'iil In ils lOn
sinii. Ih'I'Ii I' 'I'M-il liy llic I'l'iisinii nl' llic rivi'i' inln a pcrpi'inlimilar lilnll'
III' TllM 1)1- SIM li'i'l. Ill llii'si' inslanri's ll i'llplinlis sri'in in lia\i'
ni-ciirn'il iliiriii.u- Mii' cM-avalinii ni' lln' \ all<'.\ s. ami w<' may lii'lii'V i'
llial X'nlcanii' aclivilx' lii'tran al appn>\iliialfl,\ lln' saim' linn' asllir
;;'('nt'ral clcvalinii.
M'ninr liililniij. Alniii;' llii' ^'llknll lii-l -.M-i'ii l-'iii-lymi li' ( ri'i'k ami
Circli' <'il\. wln-ri' lln' rixi'r I'nllnws 1 hr liasi' nl' lln' M; nnlli Mniiii-
i'i
A :.-
'■I
i|!i.
A
I
l'(i4 (iKOl.OliV OF rilK VIKOX (KJl.D DISTRICT. ALASKA.
liiiiis. Ilic voiiiiLCi'i' idi'ks. silcli ii^ llic 'riiliUandil, the .Mi.-.siiiii Cicck.
iiiiil tlic K'friai scries, liavi' sciiiii'l iiiios a iicaily uiiii'orm atlitiidc I'ui a
(•(iiisi(lcial)li' ili^taiicc, hiil arraaaiii llirowii iiiiu folds, ol'ii'ii sliaijily
cDiniprcssrd ami vciMical. 'I'licrc is soimc sliulil t'aulliiiu' ai'ciiiiipaiiyiim
this rol<lini;'. Iiiil on llic wliolc Ilic aiisciicc of actual breaks in the
si lata i>- rcMiarkaldc. In sonic cases (liose folds are so recent Ilia I 1lie\
a]i|iear on the Mirl'ace and deleniiiiie tlie |present to|)oi;-ra|(liy. .\n
iiislance of lliis is .slioun in lii:. I'.L wliicli is a pliotouraiili ol' prolpalilv
t'arhoiii fere MIS rocks on t lie riiiiil side of 1 he ^'iikoii, neart lie Tali k and it
]ii\('r. A broad band of w Idle cryslalliiie linii sloii,- makes tlic s! iiic-
1 lire ob\ ions even fro in a distance and shows t lial I he beds are bent
!illl
Fi(^ r.i.— Aiitiiliual iiillaipl -.Miclin;!! valley 1.11 Yuk-ii lln . i- ii. ai- hl.^uiI, ..i ■rnlikiiiiilit Hivcr.
into an anticline and syiicline. 'I'lie anticline biriiis a hill and the
syiicliiie a valley, the limits of these to|io,ura|iliic features corres|)ond-
iliy- closely In those of I he folds. .Mr. K. (i. .McCom.cll' notes a similai
occurrence on the l'orcii|iiiic. below Driftwood Kivor. Here lliere
was obsei'M-d a sudden aiil icliiie which showed hard (|iiarlzites and
sandstones o\erlyii,,u' coiii|iacl, bluish, soinetinies slialy, linieslonc.
This aiilii'linal swcd jirojccls abo\'.' the surface as a hill, and the curve
of the strata is si ill unbroken by deimdal ioii, althou.uh the fraclured
condition of llio beds shows thai lliey were bent, near the surface and
no! under any lireat pressure,
'Ami K.'ri. (ic.l. \:it. Hist Siirvrv Ciiiiihlii. V.il. IV, isss-mi. p. l-;iili.
Mm
-="i:|
,
1
(■
!
F'*l:
1
I :
1 ■
m
1
s
- II
sprim.l
Pl.KiyrdCKNK MDVKMKNTS.
2G5
It is evident tliat folds like those iiiiist have tali< ii ithiee In ((nn
l)arativel\ recent time, and lonj;' alter the eNisteiice of tin' Mammoth
Mountains, which ha\e been so deeply carved into peaiis liv erosion.
The fact that the folds described alonj;- the \ nkoii ari' situated at the
foot of the .Mammoth ran.ue su;;i;ests that liiey nia\ he due to the
weijiht of these mountains, which has crumpled the lower beds where
they have been stripped by the erosion of the river, and so ar<' capa-
ble of beiuf^c easily bent; and a similar ex))laiiatioii may perhaps
hold ;;(iod for other occurrences. The vast alterations in the attitude
of strata of so j;reat thickness and weight and the ineipialities of
balance jiroduccd by the profound erosion of Tertiary tinu' < an ihit
I'ail to brinj;' about in phu'cs minor movements which tend to rotoic,
however sliylitly. the ei|uilibrium.
PLEISTOCENE MOVEMENTS.
SUinrEHCI'.NOl',.
.\i various points in Alaska terraces or rocliciit bein-hes are touinl
up to meat hei.uhts and in such jiositious that they can be explaiiu'd
(uily by the supposition that they are nuirine shoreliiu's. These are
olten obscured by erosion, ami yet are ;;enerally so wi'U marked that
it is clear they were fornu'd at no very ain'ient i)erio<l.
'I'lrrnccs in the riciiiity iif flii- l.oirrr Yiiknn, — In the Lower li'am-
paits below I''ort Hamlin, the hills on both sides ol tlie river aie dis-
tinctly terraced. JJesides minor beiulies. there is a broad, uellnnuked
1erra<-e alxuil l.">ii feet above lh(> river, while at hm to liuii feet is a
level- topjied plateau (see J'l.XX.Wl. p. Jul'), i'he lop of this plateau
iscovered with rolled ;;ravels(h'rived from \aiious sources, often indi-
(•a(iu;;by their natiin nsiderable traus])oi'tati<ui. The slopes are
.sonu'wlnit furrowed by j^ullies. but erosi(ui is eviilently \ei'y I'eeeni,
and the gullies ha\eworn baidc but little. These terrai'cs arc seiui
init oidy in narrow valleys, but where the rivei' llows, as ii does at
t inu's. in .-i uiore open count r.\ ■ and in 1 hese cases the relat ions of the
terraces to the river are s"eh 1 1 ' it seems improbable | hat theywei'o
to stream erosion. K\ en above the clea fly cut lienehes t he coun-
try has a neiu'rally le\ol and t(>rraccd appearance up to the sk.\- line,
ri. \1, is a j)hotoiira|)h taken alonir tlie Yukon in the vicinity of
the' Kay U'iver. anil shows the terracing;' rather iiulist iiietlx .
After passin;; the uM)Uth <if the Tauaiia a more complete \ii'w of i lie
Uampart Mounlaius is obtained, ami ii is seen that (uily the hii;hest
parts of th(> ranii'e ha\e bohl. sharp outlines, the li'ieatei' part beinn
(lislinclly. thoiiuh ofti^n rudely. Ierrace<i uj) to a yi'eat heij;h1.
.Vs seen from the clelta of the ^'ukon. the liiu' of probably basaltic
hills, which is continuous . rom the river across to SI. .Michael Island.
seems to form in ji'eueral a low ])lateau with wc'll-marked terraces
(U- benches, .\bo\-e this plateau rise irreu'iilar hills, which ma\- be
1
.:*
■A
■j
•_'(iVi (iKiiI,(l(;V (IF TIIH YIKdN (iOLl) DISTKIOT. ALASKA.
^1
km
\(ilc,-||iii' ni'IiIn. I'i'iiI'. I. ('. |{usscll' iilso <';ills ill tent imi In •' (M'l'lilill
(il)scur(' iiulicMlioiis nf li-rrju'i's or sea clitl's at mm cloNiitiiiii >>( l.'iiinoi-
L'.diiii l"(M'l on ,'i iiiiiiihc'i' of llic iiioniilaiiis iicai' tin- ^'llkoll hclow
Xulalo." Il is not ccrlaiii ulictlicr Ili(' scarps nolcil liy i'rol'osor
1 JiiNScll arc I lie same as I liosc aliovc dcscrilicd.
7
I'ri'dci s 1)1
I /.s7<(//f/.s- /// //)' sill. — Diirini;' a slav of a I'ew ila\s al
liarliorol' lliiiliiik, in llic islainl of I'lialaska, llic iiiouiilaiiis risiiii;-
|ircci|iitoiisly alio\c the post were as<'ciiile(l. 'I'liesc inomitaiiis arc
(■oiii]ioseil alliiosi eillirely of iiiiieoiis rocks, soiiict iliics massive, liiil
irciierally porpliyrilic, wliicli licloii;;' cliictly lo llic iliorilc-aMilc--ilc
family. .Vll lliesc rocks areallcred ami have mil 'he appearance of
\-er\' rcccnl oi'ii^in. \Vc mnsi pass oxei' fiirlher ilcscriplioii of the
ruck {feolojjjy. ami eiinliiic oiirschcs lo llie lopourapli.\', wliii'h has
direct bearini;' on llic (|iicstioii nmlcr ilisciission.
The island at tills point has a vi'vy Irrcunlar ciiast line, lieiiiij;
Invaded liy sharp, narrow liords. In the inlerior llic lopourapliy is
roimli ami varied to a reniarkalile deyrec, the peaks lieiiii.
liar[)
and the ilrainau'c system so Imiierl'ecily dcvelo|)ed ihat the sceneiy
possesses a peculiar wildness which is rarely seen even in moiinlain-
ous districts. The trip from the liarbor was made southward alony'
ihc sliorc of (aplaiiis liax' pas! llic fool of the iiionnlain set down on
ihcCoasi Siirx'cv Chan '.111117 ms I'\raiiiiil .Monnlain 1'
■I'hen
lurniiii;' lo Ihc left, wc ascended Ihc luoiinlalns and allained tlio
ridne contlnnons wilh hnl to the east of Pyramid .Monnlain I'cak.
To 1 he soul h of I his ridu'i' ami l<i I he iiorl li arc rude yaps in I he hills
In which slreaiiis Mow to ihc ocean. To the soiilli was the yap in
which wc had ascended, while that to the north collects llic walers
which linally How Into the ocean at the jiosl of [linlink.
From iliis elevated posillon and ilnrinn' the asceiil of oiicnap in ilie
hills and the descenl of I he oilier, certain feat 11 res of toponraphy \\ liicli
were not easily visible from the shore were slroiinly bronuiil mil. Il
..a 'hen seen I hat ihc entire islaml up lo an eslimaled helizht of l.-'iim
feel aliove I he sea is (list iiicl ly terraced. These terraces ap[icar to be
nearly hori/.ontal, and conform to all the Irreyiilaril les of Ihc toponia-
[iliy, beliiii-, imieed. as well marked in the rude \allcysas cm the pro-
jcctinu' rldu'cs. Theycan be discerned nearlv everywhere, but are best,
seen aloiiy- the side of the \ alley which leads Into the liord al Ililllink.
Here half a dozen orsostroniily marked benches arc cut dcc[i into t he
bed rock, and many well-markcil minor ones. As the a\crafi'e u'ladc
id' the \allcv is very sleep, the hori/onlal benches run into the valley
boitoin in rapid succession. Tlioretbrc II happens that the streams
examined Mow one after another o\ er these bemdics; and on the lop
of each the stream wanders in elaborate meanders, dlxciiiinu and
splitting as in a della, and then, at Ihc end of each Mat, it tumbles
over an abrupt ro(d< el ill', often luii. I'liil, or c\cn :!imi feel liiyh. So
' Bull. (Ivul. Sill-. Aiui'i-ini. V.il. I. p, rsi.
sri'itn-l
Pl.KISTi K T.NK Ml iVr.MKNlS.
•i67
sleep ill'e these elilVs tllill it is ufleli ilillicillt In cliiiili n\cr I lielii. .1 ml
the slreiiiii roriiis a waterfall m- i-a|iiil siieeessinii nl' wati rialls In llie
holtoin, wliell it anaili lienilis to lueaMilei- lliroiiuli a s\\aiii|i\ llal.
Soiiietinies tile slfcaiii lias worn hack a sliuhl caiiynii in llii' I'aee of
tlie elilV, so that I lie I'all is mil sn aliru]il. liiil in <ii liei- eases 1 lie aim uml
III" \veafiii;;-ha<-lc i» very sliulit , ami there is an alimisl i-dniinniMis
walerl'all IVoiii one lieiich tciamither. 'I'iie islam! is e\i iemel.\ uill
walereil, the snow cm lln' imnintaiiis lasliii!:- tlinin,i;hniii the y.iw aii'l
tlie faiiifall liein^- ahiimlant. The hills aii> envere'i In a liei-lii <>(
aliiillt l',Olill I'l'et with tllieU limss. wllieli linhls liinislure like a sjinULie
and eniilinnniisly jeeils the in nnimTalile rills uliieh start e\eryuliere
from the imiMlilain tops. All t liese litt le rills likewise deseeiel IHmii
one terraee to another, so that falls are very nmiieroiis. while mi llie
llat surfaces tliewatei's form ititrii-ate meaielers. marshes, or prel ly
]ioii(ls.
These rock lieiiehes eaii he nothiti.ii' liiit sea elilVs. ami till' small
ainoniit of erosimi whieh the streams ha\c arenmplished shnw a
comparatively receiii ele\ation of 1." feel or so. The ele\ at ioii
llllisl have been iiitermittent. since the .-ca remained Ioiil;' enniiLili al
I'acli level to car\e a (dilV. and the'ii receded .so rapidlx that il in 1-
plishcd little erosion. The dee]ily cut heiichcs are alioiil half a do/.en
in uumlier. showinu' tin' same niimlier of snccessi\i. uplifts, which
a\'era.iicd Jnii or..'li"i feel each.
in this eoiineelion it may he noteil that cm the riuhi side of ( ap-
taiiis r.ay a waterfall is seen deseendin^ the perpendicular lai f the
rliff into the .sea. and this fall is said to he 1 1'd feet liiiili. < »n the
shore near the \ iUa.iic of iliiiliuk man\ shells were loiiml in nooks of
the ro(d< al idevalioiis which would seciii to he several feet aliove the
reach of the hiniiest waves. These were ipiite fresh aii<l iinliiokeii
and occurred in lar.ire (luantities. as if the animals live'l in the placs
wiiere the shells were found. These and other cvideiu'cs. which will
lie incntioiied later, point to the conclusion that ihc island ise\cii
now lieinii: uplifted.
The ti'ifaeed fiu'iii of the mountains surroiindinu' Captains liay,
whieh has Just heeii descrihed. is clearly shown hy hachiire lines ,ai
Coast Survey Chart No. '.10117 of Ciialaska I'.ay. <»n the small island
of Ainaknak, which lies in I'lialaska I'.ay ii.'ar the post of Iliiiliuk,
I'rofcssor Kitssidl ' notes that the lower slopes have a numdeil and llow-
iniioutline, whieh is limited in the upper portion of the im.unlain liy
an irivunlar scarp, above whieh the inoiinlain slopes are stt-eper and
more angular. I'rofcssor Kus.sell su-^icsts that the scarp may he the
upper limit of fonm'r iiiaciation. or that it iicy he an aiieiei" sea clilV.
At the island of ruii'M m> ojijiort unity was ha<l for elimlnnn' t he
monnlains. l.iit from t he slior.' t he island .seemed to show rude terraces
up to il e.msidorahle hei-ht, jiroliahly at least I.Oi^m^ a^M^ive the
nip. .11. |,, i:i'.i.
W;\
■-.ft, ,
mil
iitiii
if
il'.oLdGV OF THF. YfKO?! GOLD DISTRICT, ALASKA.
sea. mill I lii'i'i' isii
will 111' L;i\'i'M liitcf.
llsi) I'XCI'lll'lll u
vidciKM' of \iTV ri'cciit flfViitliiii. uliii'h
n.-ihi
il
li;:';i wi'iT
Ihr iilih' t\M) IslilMils of liiiMllllililloils
cliariii'IiT wliicli wiTi- very I'losi'ly aiiproai-lifil, yrt lln' iiKiiinlaiinnis
slioif hi'lwci'ii llicsi' two islainls sccincil to slmw iii-arly <-\ cnwlicrc
ilir >aiiii' li>|>i)L;i'a|iliir |)i'c',iliai'il ii's. <
Till' iiliriHiiiiciia which haxi' hccii (loscrilifd riuiii llic islainls iii
■liim >>''a arc niily I hose vv
liicli show il vcr\' jii'cat siihincr^'ciicc in
lhcsc evidences will hi' coiisideicd
coni|iai"iti\i'ly leceiil lime. Al all 1 hese localil ies, and at a niMiilier
of oilier-, there isalnindani e\-ideiice of elevation in e\i i-eniel.\- recent,
and |ii'olialil.\' in |ii'i'sent time, am
later.
I'l i-i-iiri s (III llii I'l'i"!' Viihiiii mill )f iijhhiiriiKj n ijiitiis nf Uri/ish
Cnliiiiihiii. It has alrcad.x liecn noted thai the dee]), well-marked
valley of the rpiii'r \nkon is dislinctly lerraced up to a \eiy ureal
hei.uhl. l'r()l'<'ssor' Unsscll' dctermineil a terrace near the interna-
lional lioiinilary on the Yukon to be 7:il feet above the river. .Mr.
I!. I i. .Mc( onnell ' notes that on the ^■nkoll ii short distance hehiw the
mill of the I 'llv rolled uravel.s
evidentlv deri\-ed
from liroken-
dow n teiraces. were found in some alnindaiice up to a lieiuhl of siiii
fiet. .Ml aloii.u the N'likon \alley Icri'aces are abundaiil. Ihe lower
ones beini;- of ,iira\el. while those at a \ervhii;h elevation are less
•rfeci in form ami lia\ e the a
ppeara
nee of lieiiii' rock cut. ( )n l,al
i.iiKleman. as alreaily noteil. is a well-niarke(l jiravcl terrace al a
hi'iyht of abiiiil ."ill I'cet above the present water le\el. whileabo\e this
iii'avel terrace is a broad, well-imirke«l bench which appears lo be cut
in I he solid rock.
Dr. (J. M. I lawsoii' has noted well-marked terraces al many poiins
in the drainaue of ihe I pper Viikoii iind in the in'i;ihboriii,i; re.uioii of
liiii ish (oliinibia. lie tinds that the liiLthesl have an avei'aji'e eleva-
I loll
aiioiit
'.III feel, while the\ha\e been found between ."i.noii
and l.iiii" feel in a niimlier ot widely separated localities, thou,<,'h the
principal deNclopmcnt is below :!.siiii or :i.."iini feet, lie remarks:
Hflow a lici,i;ht of aliniit :'.,ililii feet tlic wliole liiti'rior PlaU'iiu ri'i;i(iii niiiy lie
(Ipsrrilied as tcrraoiil. anil iiltlioui^h along the various river valleys iiiiiny lerraies
occur whiili liavcevidt'iitl.v bwu jirodnccrl liy the streams themselves wliili'inrtiii]L;
down throuKli the drift deposits wliicli at an earlier stage had tilled these valleys,
these need not tie eousidered lii-ri', the 'wiiut to which it is wished to draw atieii-
tioii lii'ing the existence of terraces reiiniring tor their explanation a general Hood-
ing of the country. Such terraces are found to he not cotilined to the inmiediati'
valleys of the rivers, Imt to o;'eur in ditterent situations along the higher .-'oiie<.
anil to friuLTe at similar elevations the various irri'gnlarities of the plateaus.
y.
rrnri .s i,)i
/III I'liiriiiiiiii . — .Mr. K. (}. .Mct'onnell^ has noted on
the mounlains between the .MackL-iizie and the Porcupine draii
' Op. .it . |>. Ill
.Mill, Ui'pt. lii'.il. Xat. Hist. Survoy ("iiiindii, Vut. IV. Isss-.sii, ji. :.ND.
'Ti-ai.s. Huval
. raimilu, V..1. VIII.
. pp
:i<rll.
Ann. Hi'pt. o.'iil. Xat. Hist. Siu-voy Ciiiiuila, Vul. I\', Lstw-Sii, p. :.'ri>,
It
t I
FH
SI'I-IIK.1
PLKt: ''DCKNE Mi >Vl:MK.\T!*.
2i;!i
tc'lljic'fs ill nil elevation (if l.."iilll iVel and linile ahoN e tlie sea. "Ilile
aldllLTllie Upliel' ])ai't of tlie I'olcilpi lie l{aill|ia rt s eoal>>e niav el-» Were
noleil ill \ arioiis |ioiiils ii|i |o ele\ at ion^ of Imi or 'hhi iVci aliovcijie
sili'faee of I he ri\er.
Siiliiiii riji iici Inil iriili il III/ /(/■/•<((•( .v.- 'I'lie^e |ilielioiiii'lia imii lie
explaineil only iiy tlie siii)|iosilioii that in eoiiiparatix cly reeent limes
the sea stood at a lliueli irreater elevation Iliail at |ire>eiit. (>\,-\- Ihe
urealei' |iarl of eastern Alaska and adjaeeiit pails of llriiisli ( oinm-
l)ia t he <lit1'ereliee ill elevation lielweeli theaileielit shore-lilie and the
|)reseiit was pi'ohalily at least li.iion feet, while the lerraees mi the
I, oner \'iiUoii and of the islands in the sea, such as I'nalasUa. -liow
an elevation of I..M111 m- J.IIIMI (,;-\ at least, Siliee Ilie deep valleys of
the re^jion had all been exeavaled previous to the depression, these
valii'.vs iiiilsi have been eoiiverleil into fiords, and so liciieln'v nf
marine ori;^iii vvniild iiat iirallv hav e heeii formed on t heir sidi-.. It
is iii'oliable. thei-efore. that maiivdl' the hiiili lerraees of llie ^ukoll
X'alley and ot her dee|i-ri\ cr valleys may lie due to nnirine aet ion. and
that the li'ravcls which eiienniher theni iiia.v at times have the same
oriilin. In support of ihisit is to he iioied ihal t hese i^raveN nceiir
not only on the lerraees aloii^' the river vaUev. Imt. so far as vn
inea^erly noted, at many oliier |ioints ov er t he v\ hole eoiiiit rv, 'I'lii-y
are full lid in the bottom of theaneieni valleys which existed before
the \e<ieeiie uplift , and also dii the di\ ides between these v allc.v s. In
the Lower Uaniparls of Ihe ^■ul<on they ciiv er a broaii. level plateau
('i(iiior7tH> feet above the river, and on t he ^ppcl■^■||koll iIh^v have
been noted as much as Slid feet above t hi' river. I )r. (i. M. Dawson '
notes that Ihe summit ot' an isolated moimiain on ihe vvalcrslicd
between the I, lard and the ^■ukllll river svslcm^. at ;i licii;hl of l.:loo
feel above Ihe sea. was found to be slrewn uilh rolled sloiies of
diverse iiri.uili. such as to show that walcr must have stood at one
lime about l.i«"> feet above this part of 1 lie racilie-.Vi'cl ie walershed.
I'l r'niil III' ill iHi sNidii .Vlthou.uii ofleii millilated by receiil erosion,
the liii,di terraces which have been described conform in i;eneral willi
the present topoi.iraphv. follow ini:- all the, ureal irrei,Milarii ics, such as
the nioiintains and t he lariicr valleys. The diep valleys, as before
noted, were probably eroded chiellv in I'lioceiie time, since ihcv cut
strata which have been rererred to the .Miocene, while thev are older
than the period at which the cordillerali .i;lacier e.xisled. The sub-
sidence of the land, therefore, which enabled the sea to carve terraces
onlhe faces of I liese valleys, must havetakeii placeinlate j'lioceiieor
early i'leistocene time, 'i'his is in accoi'danee with the coneliisionsof
Dr. <;. .M. Dawson.- which vvei-e derived fiom a st inly of the lilacial
phenomena in the drainage basin of the Cpper Yukon and in tiie
adjacent parts of llrit isli (oluiiibia. Dr. Dawson supposes that eer-
■ Trails I!..viil .s..c (1111:111:1. V.il. VIII. >f'. I. p. ^l'^.
■-(Ill . ■it,. 11 I-'.
• i
I
•_'70 (ir.()i.(i(;v or tiik vl'kon odM) distkh t. alasica.
tain trlficiiil <li'|insits « liich slmw cn iili'iirc nf waliT aclidn, ami u liii-li
Mii« iMMMiilliriiiniliMiil llic u'lacialril i-''i:ii>n at Minii-wlial miit'diiii li'\cls
hclNM'cii l',."iIhi iiihI :;,iiiiii iVcI aliiixr llif N"'a. wcri' (li'|iiisilr(l in lln- sea
wliicli at ihal lime wasln-cl the icliTatinu' IVnni nl tlir uiai-iiM'.
.\lisi iii-i III' i/hii-ioliiiii mill riirl: i/< <r///. -'rinonuliont rn'aily tin'
« linic (iT .\iasl<a llicri' ai'i' nn >iyii> nl' rruinnal ,uiaclalii)n. 'I'lic iiori li-
ciii limit 111' ll uniilrv (ivit uliirli llic curdillcran ulacicf miummI is
clcailv (IcIiniMl. ami lia-- lirrn I'ccumii/cil by cmtv u:('ul()u:isl \\\\u lias
liaxi'li'il ihi'iinuli iliis I'liunlrv. 'I'lir line iiiaikini: 1 liis limit may lu'
liiavvn t'lom llir l.cwi's. al a iminl lu'lnw llir jiii; Salmmi liiMT. IuIIh'
While lii\<T. ill till' \ii-inily of ilic I )iiii,ii'l<. ami I'limi here to ilic
ili\ iilc hi'l wccii I III' ( opiicr ami 1 Ih' 'i'anana ri\cis (sec I'l. X X W 1 1 ).
Ill lliis iiiiiilaiMali'd rryiciii, Iiuwcn it. IIii'I'i' is very litllf I'i'sidnal flay,
ilii' nicUs lii'iim iMim|iai'al ivcly I'n'sli ami lianl u lin-i'V it <'\|iusi'i|,
ISiiili ihc alisi'iii-r III' irlaciation ami nC ilrcaynl nirk scriiis id iTsnIl
III ssarily rnmi ll mlilinns >>( snhmiTiii'iicr. wliii-ji liavr lici'ii
ilrilniM'il as piolialily I'xisiini: al a iMiiM|paial i\ I'ly iccimi' timi'. run-
li'iii|Miram'ons in a i:'('ni'i'al nay uiili ilu' maximiiiii i^iacial inn. 'rii<>
I'ai-l 111' snlmicriii'iicf I'Xiilaiiis ilii' alisriicc ul' \^•(^ aclimi. anil llii' saiiii'
icics wliii'ii
i\(mI icrrai'cs or inarinc slmri'-lin
cnisiM' aui'i
mn.>l iH'i'i'ssarily lia\<' swept away aeeiiiiiiilaliuns ut' ileeayed rock.
'I'lie proeess ol' ruck decay is \ery slow a.s compared with tlic processes
(if disinlcirral Ion and erosion in laN'oraliic |ilaces: ami llie amount ol'
siicli decay which lias taken place in Ihe rocks all u\cr Ilie i,'laciatcd
portion of North .Vmciica since the retreat of tiic ice is \cry sliulil.
I'lolcssor h'lissell' explains I he alisence III' ileeayed rock ill .Vlaska as
a lesiili of climalic conditions. I>iit in \ lew of llic considerations
staled, ii si.-ciiis thai the conditions in Alaska will not fiirnisli any
e\ii|cnce on liie ipiestlon of rock ilecay as a climatic function, since
tile ihickness of roitcii rock swept away lp.\ inarinc action may iiavc
liccii coiisideral)l(\
I;K< KNT KLi:\.\rinN.
'I'iiat 1 lie land could not iiavc remained loiii;' suhmer;rcd In tlic extent
Just ilescrihcd is siiow n by tiic coiiiparat i\ c pain-ily of tlie records
which litis submergence iias left. Certainly t he depression was mil
loiiU' eiioui;li III permil the ;icciiiiiulat ion of sediments of any ;;rcat
ihickness jilonu' the siiorcs of the sea. for the only deposits that can
be I'cferreil to inarinc act ion at this epocii arc t lie rolled urax'cls. w hicli
occur cxcrywiiere ami at urcat iicinliis. The land, therefore, after
liaviliii liecii rather rapidly deprcsscil, wasauaiii as r.-ipidly elevated
lo the position in wiiicii it is to-da\'.
'I'iie extent of tlic recent cicxation is determined by the same meas-
urements as those wliicil lia\e been used tosliow llie pre\ ions depres-
sion, nainely, tiie lieii,dits of tlie imii'ine terraces above the present
sea level. Ill oiic case the scarps car\cd at equal levels on a land
I Xiiti'scii till' r.iirlaii' (.'■■"lufiy III Aluskii.- Hull. Ucnl. .s,,.-. .\iij,Ti.:i. Vol. 1, p. l:il.
''{ 1 t
Kl'l nil. I
I'Li;i>r(K INK MmVI.MI.NI-
271
Mil rncc. ('uiii|«ist'(l (if \iirifil liilK, iiiiiiiiil.iin^. :iiiil \allt>vs. >.liii\v llml
mI'Ii'I' llii' I'lirin.'ilioii ni' t his htinl Mirr.-iiM'. diH' in ;: Ioiil: |M'i'i<ii| ul'cni-
>\n\[. 1 lie rt'^jiiiii "Ms slink lii'iir.ii li I 111' sill ; u liili' ill I 111' iillii'c insliiiifc
I 111- licijrill 111 wllii'll llli'sf li'lTili'i's lliiu siMllil ;iliii\ !• i lie |iri'si'iil M'.i
|r\rl Irslilics 111 III!' r\1flll 111' llli' s||lisci|llf|ll i'lr\ ill inn , ImiIi'ImI, in
Ihc liillcr ciisi' llic I'l'ilci-ioii iiM'il i-. lairly aiTiirali'. Inil in llic rnniiiT
mil iH'ccssai'il.N SI), siiK'i' We can mil sal'rlx assiiiiir i lial tin- I'lcv ai imi
111' ilii'lainl prrviiiiis In I lie lii'iircssinii was i lif sanii' as il is in-ila.v,
anil I hi'i'i'l'iiri' tlii' |iri'si>iit hriulil nl' llii' inariiii- IrrraiTs alin\i' llir
SI a is 111' ilsi'll' nil \ rl'\ arrnrair i-rilrrinii 111' I lir aim HI 11 1 111' •|i'|ilrssiii||.
Asa iiirans nl' iiinrr I'ldsclv asi'i'i-lalninu' llif I'Mnii nf lliis ili'|iri's-
sinii. Ilir ili'r|i rixcr salli'vs, wliii'li wi'i rmji'il in I lii' iinini'iiiali'ly
|ii-i'i'riliiii; |nTiiiil. ina,\ lii' laki'ii inin ari'iiiini, siiii'f ilii'\ may si'ivc
111 ilrli'rniini' aii|irii\iinalrly llir |insiliiin nl' ilir ain'ii'iil sjinir liiir.
KVIIiKM l.s nj- UKl KNT i:l.K\Mln\ l\ llli: I STl.l:l' HI.
I'.i'siiirs tlic Ici'rai'i's. ill llli' inlcrinr nl' Alaska llifri' arc in lie rniiinl
III liiT i'\ lilcnrcs nf i'nni|iai-al ivi'l.v n'rciil clcvalinn in llii' ilciinsiis in
ri\ IT \ alleys siii'li as ilia I nl' I lii' ^■|lknn. < >n lliis i-i\ it ami ils i rilni-
laiii's ail' thick ilcpnsils uf sill, which were c\ iilciilly laiil ilnwn in
ijuicl walcrs. 'I'licsc sills ha\c already liccii ijcscrilicij I'lnin nianx
|ilaccs, ami the area nf their ffrealesl exteiii is iirnlialily the ^■|lknn
l''lals. uhel-e llie\cn\er all area 111' alinllt l.'i.iillli si|liaic miles. All
Ihescsill ilepiisits liaxe lieeli cut llirniiyh liy I he |iresenl ri\ el's, which
havcalimisi always a rapi.! cnri-cnt, iiiit'a\ nrable In I he ilepnsit ion nl'
i'.nc material. .Viinxe Lake l.cliarnc. mi the N'liknn. I he sill hliilVsare
as much as l.Mi feel lii.uh, ami al the I'alisailcs, mi the l.nuei ^■||klln
ai'calinul I he same lieiejit . while at .Myi k Creek t hey are .Inn |'i'|.i
nr llinre al)n\e Hie river. -M lllese two last- liailieil liica lilies I here are
fiinml ill the silts niiinci'niis frcsli-waler shells, all lielnnuiiiL;- In lixiiii;
specirs, .Mnli;.;- pnl'tiiilis i>\' the rivers, where the silts llli lint ncelir.
there are. np In ciiiisideralile heiulits. aliimst emit iniimis i^rax el ter-
races ihriiiiiih wliicli the streams have cut. It seems prnlialile t hat
the liraxels are ihiived frnm detrilus with which the deep \alle>s
were jiartially tilled at the time <>\' the siilniier,u;enee: while the | ul-
iarities nf the lirnad. deep silt depnsils indleale liial they were furmed
ill niimermis lai',i;c. shallow lakes siiliseqiieiit to tin einerueiiee nf Hie
land frmii the sea. Init he fore il had attained ils present elevation.
'I'liese lakes were drained ill cnlisei|llem'e nf flll'tlier Uplifting, aeemii-
lianled liy sliiriit lilliiii;-. which aceeleraled the drainayc. so tiiai lakes
and slii,ueisli streams lieeame transformed into rapid rivers. 'I'lie
record of this sudden chaiiue is found, ainmi^- other places, in the thin
laverof river uravels wliicli lie on top of the hiiili silt ItliilTs on I he
I.ewe.s and other streams, Tlicse ji'iavels. contrasted with the iimler-
lyiiii;' silts, show a sudden inerease in the velocity ol the water, while
the thinness of the uravels shows that llie stream, in ciiiisei|iii'iice of
m
'■iir
,t
■i
212 (ii;iii,ii,,s til' Tin; vi kun cold lusrwii t, ai.aska.
il> illl'ICilMMl \rliicil\. I'!l|li<ll\ rill duWII until il rcjll'llcc I il^ |ilvsc|i|
I'liamicl. Oil III!' II 'N i\iil III' ilii' iii'liv il.\ ol' tlii'M' si iimiiis st uT iln'
laki's "'i'' ilraiiii'il. ami tln' ili'|ii(»ils wliirli hail arcmmilali'il in ilii'in
aic MOW iMii lliiiiii;:li liv Wiv ii\i'i-. riiriiiiiiy; hind's wliicli \ai\ in
llfifilil ai'iMiiilili;;- In llu- cMi'lll to wllirll IIii'm' scililllCllts lia'l rllnknl
ii|( till- I'lianiii'ls III' pr'cN iiiiis i|i'aiiia;.'c. A I I In- same liiiii' I In' Lii.n I'ls
wliii'h hail aci-iliiiiilatcil al Narimis pDiiils in Ihi' uhl valh'Vs uiti' nil
lliiiiil;;li. riiiininii' Ihi' Inwi'st nl' Ihi' [iii'si'iil iriaxi'l Irrrai'i's. I'hi'
rapiility of Ihr prrMMil si rrains ami I hi'ir iiiinliliiii'ss shows lhr\ ai'c
siili i'n,i:ay;ril in artivi' cnii iny.
1,\I1i|;MI;s o| i:Ii kni- KI.I'.VATION AI.oNii tiik coast.
SI. Miiliiiil. — St. .Mii-harl Islaiiil rises i>riliiiaril,\' t'niiii JiMo ."in t'l-i'ti
aliHNC the sea, cNccpl in lour or li\(' plarcs uhi'ir llnir appear iini-
lienet'S, uhirli oil exailliliat ion are rollllil to lie aiieiellt \'ii|eanii'
crators. 'I'lie material ol' tliese emineiiees is ulivinu-hasall, ami small
(lows of the same material are exposeil in plaees aloiij,' (he shore. Iiul
the main part, of the islam! is eninposeil of walerlaid ■\oleaiiie ash,
leslinu' in plai'es u|m)1i a lieil of chiN coiitainin;.; ill-assorieil pelililes of
various sizes, which slronyiy sii;r;;esls lee i.etion. In the walerlaiil
ash are liow lilers of roeks foii.'iun lo the islaml, which are larire ami
snliaiiiiiilar in shape ami lie in such a inaniier as to imlieate t hat t hey
iiave lieeii droppetl from sonu,' ic(> eake. ]n the ash are I'oiiml sticks
ami holies wliieh ap[)eai' (plile fresh.
A .short (li.stanee from the post at .'st. .Michael is a small islet know n
as Whale Island, which is separated from St. .'Michael hy a shallow
strait much ulist riicteil hy lar.i;e rock frauinents, as iiiay he seen on
Coast Survey chart \i>. '.i:>7."i and in I'l. .\I,I. Tlirouuh ihissirail
the tidal currents are notii'cahly st ronjr and coiit iniially niidercui t he
hliill's. On the SI. .Michael side of the strait that pari of the hliill'
which reaches (lilt toward \Vliale Island and seems to he a <lirect coii-
tiiuiatioii of the reef which lies helweeii the islands, is eoni|)osed of
blocks of piniiici', solid la\a, eon!j;lomerate, shale, and sandstone,
oinheddcd in a inatri.x consist iiii,' cliielly of volcanic ash. .Mlhoimh
the howlders are very laru'e and siihanu'illar, yet tlie liner material
shows a riiuuh stratiform arrani^cmcnt, as if laid down in water.
'J'akinu' into consideration the \ariei\ of material, which indicates
considerahle Iransiiorlalion and shows that the rorinalion can not he
a clitV tains, it seems prohahle that this di'posit must he the result of
ice action, since il has all the eharaciers of a typical moraine. The
sandstone and .shiile luiwlders, however, and nsnally the inimice-liko
lava, are so softeiieil and deeomposed that the moraine could not ha vi^
l)een formed within the last few years, and, as already staled, there
are indications of its havinji Ijcen formed under water. This dejiosit
is only found mi the point of the island ni'.xl to the strait ; a short
(lislance from the strait it is found to lie hiterallv ayainsl solid lava
-I
.'i
bit
ISl
ul
w
Wf'
'f
siimi.]
lM.KISTO( km: MOVr.MENTS.
•jt;5
Ix'ils Willi liiyci's of wMlcrliiid XDlcaiiic ii--li i-ni' liiiiiiL: \fvy little
iiiiilei'ial In wliii'li a uiarial ofiiiiii <-aii lie ax-rilii'il. 'i'lii- I'M-ali/ai ion
points to llic cxistcncf of a iiiafini' cIliTi'iil similar to t li il of lo-ila> at
a time wlicii the island was holow the |»i-i'S(Mit li'xcl. a id this ninciit
niiist at I iiiii'sliavc carried iee in lai'u;i' aiiKuinl. wliicli, ^riiidiiii;- aloiii:
I lie sliofes, pfodlleeil the moraine w]ii<'1i lias lieeu de^ei'il led . I See IM.
XI.II. p. -'71. )
Tile 1opoe-rapli\ o|- tlie i>laiid is. as a rule. \ei'\ sliulilly dilVereii-
liateil, and shows all the niai'ks of ocean cin'i'eiit >— -liroail chaniieK
with the low banks wliicli ci-oss iiari'ow parts ot' 1 he i-l.-iiid. and uhich
wore once e\idciitly straits: basins made b\ soiin' edd,\ in I he marine
ctirrciits, and other mark's ol' a shallow sea bottom. .Uoii^- the --liore--
of the island, moreover, are r;iised be.-ii'hes at x.'iriou-. lieii;lits abo\c
the water, and on the most recent of these there is e\ idence that an
(dcNill ion is now uoinu' on, since lines of i;ra\ els h;'\i' been thrown iqi
which arc a|i|)ai'enlly beyonil the reaidi of thehii;hesi wa\e>. .\ccoi'd-
ini; to a t railer at St . Michael, t he old men amouL;' the n.it i\ e l-'.>kimo
say that the island is now risini;' and is hii;hei' than wln-n llicy uere
y on 111;', and it is widl known amoiiL;' the nal i\ cs t hat pile-, ot drift w 1
may be foniid at points when' there is now no water, the >ea haxiiii;'
I'cceilcd foi' considerable distances over nearly level Hats.
/ '//(//(/.s7,r/. — 'i'lie hiti'licr terrace-, on tlii' island of Inala-k.-i ha\i>
already been describeil, and the lowest oiie>. which are now close lo
tile sea and are so recent as to be |)erfect. will now l|i noted.
.\bo\ !• t he bc.-ich at t he port of Hi ill ink t here i-- a well uiarked >carp
whi(di was el idcntlv" rci'cnlly a bi'ach line, and yet Ixdow the t'oot of
this sc.irpfora iiiiiiiber of fei^t th.e lev el Mirt'ace i-. heavily covered
with arass ami ap|iears nevei- io be i-caidied by the liiL;li<'st waters.
.\bovi' this scarp comes another level, ^rass-covei'cil surface, which
stretches back io i; third scarp, which, howevci-. is less regular in oiii-
line. .Vbovi' this still other terraces may bi' distinct ly seen on the
hillsides up to a ,i;r(-al heinlil, tlioiiuii oftt ii obsciiri'd by I'l nt erosion.
The lowest lerr;iei', how ever, vv liicll has been melil iolled as beim;- clo^e
to the bleach, conlnrnis 'cry nearly in outline lo the preseiii beach,
except 1 hat il i-. 1 he arc ot' a smaller circle, (in the bro.id Mat top of
the tirst iierfect terrace all the houses of the port ot' liiiiliiik are built.
(S.e I'l. XMII. p. L'Tti.)
I'lii/ii. (In I'liua Island. es| ially aronnd Si|naw llarlior. the
rcei'iii icrracis are \er\' strongly marki'd, the lowest, which is only
ab(Uit li feet aliove the present limit of liiuli waters, following;' all the
curves of the present shore line. The' highest lei'rai-es are not so
I oni imioiis. but an well marked at intervals.
0///I /■ /oe. /////< .v.- -The t'ollowiliu' I'Viilellccs ot' recent elevation of
land in lierini;' Sea liave been iioIcmI by l)r. (>. M. Dawson:' (in St.
■ (ii'iilnni.'ut lilt.'-; ..11 s iii...t 111., i-.ia-t" .111.1 1-1:111.1.. ..f HiTiiii; s..ii mi. I m. luity lii'!. I i.'ol.
S. !■. Anu'riiM. V. .1, V.
i.s (ii.-.oi. I'T ;! — 1.^
It:- 5
^^n
^
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s
II
-m
i
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ill
4
-Jl \ (ii;i):.(i(iv oi' 'iiii', YfKON (ioi.n ihstrk t, ai.aska.
r.iiil l>l;iiiir Idiiio nf walrus mimI whale arc rininii hi (•i>ii.->|ilrralil(>
jiliiiinlain'i- (•iiilii'iiiicil III saiiil.v ili'iinsiis aliinil In reel al)ci\<' llic hiyli-
<'sl lr\i'l III' iiiipilcni Niciriii wasli. (>ii St. Lawrence Island,' al alioiii
Jill I led ali(i\c llie sea. Is a level plalcaii. wliicli may he an ancient
plane 111' marine ileniiilalidii. ami wliieli has a fairly disiind terrace
at an ele\ al imi nl' a I mi 1 1 ."in lee I almx e t he sea. Al 1 lie island nl' .\l ! II.
the westernmost in I he .VIeiit ian idiain, ;ire .ilsn evidences of rcecni
elcxaliiin. Dr. |)a\vs(in ■' says:
.\'p'iul ( 'liichiiu'ei ll.irli'ir lh>'ri- iirc smm' wpll-iiiarkcd old sea rlilf- risiin; ln-liiiiil
liravejly Hat- '.'II or :tii feet 111 li"iulit. ami sui-li us te iinlicaic an cicvaliuii nf the
l.-iml liy lliiit iniioiiiit sine- their ' iriiiatidii. On the shijies of t'n' viilyr en the
West side of the liaihor sevonil . lintly iiiiiire.ssed horizoiitiil lines also aiPiie,!!-.
the highest lii'in,:; ahoU! :iiill feet ahove the sen. They seem to it'iireseiit iiiciiiiem
tei-nit-es, anil if so, must iiidicare a soniewhiit rapiil elevation of the land, siieli ,is
to prevent any hin,i;-i'ontiiiiied marine action a( any ii.'irticiilar level.
\\ (ajic \'anciiii\ er ' a fairly distinct terrace was iihservcd al a
ilci^illl III' Ml Id Inn feel aliiix c llie sea. On t he .Vsiat ie side iif the sea,
(III the jieiiinsula id' Kanicliat Ua, ' a plane id' marine ileiiiidalion u.is
Hilled at aliiiiit 7nn in sun feci almxe 1 he sea. '["Iicre is also evidence
ol' imire recent elcvalinii ill that llie valleys which have heeii cut
dipw n I hriiuuli Ihis upper plalean tcrminale at aliniil .".n or inn iVcl
aliove the pres. ill sea level.
Dr. \V, II. Dall"' Holes that ai I'oiiil Ihiirow a siial't siiiiU loai nth
of oTl feel passe.l tliroiii;li siic.-essi\-c layers of innil. sand, and line
jrravel, with fraunientsor drift w I and niarine slndls. The foriimtioii
was clearly a lieacli alluvium, and so receiil that a pair of I'.skimo
woiideii snow e-oufiiles with a siiieu striiiu' still attached to them was
riiiind al a deplli of -27!. feel.
roM-|.rsliiNs \s 1(1 Ki:i K.\|- |-.i.|-.\- \llci\.
'I'lie instances cited show thai imisl of .MasUa is al present risiiii:',
and t liai this elc\ at ion has uom. on f,,,- .| imin- i inic Indeed the i ran-
,silion of the Nt'iy n lit sand lieaches and low sea cliiVs to succes-
sively lii;jlier and liiuher ones, which Itecimie more and imire did'aeed
liy enision, indicates that I he presenl iiiov einent is only a emit iniiat imi
<if the uplift, lliat in ciimparatively recent times has ainoiinleil to
.se\ eral I holisaild feel ,
('oiiipariiiii' the amount 1)1' this uplift with llieanioniit of previmis
depres^iiiii. w- in: y iinic that dee|i valle\s whiid; were eroded suli.e-
(jlieiil to the Nc' ceiie uplift How e\ist as liords on I he shore- of i he
(inlf of .MasUa. while ihe shnros of IJerinu Sea. on lli- contrary, are
low and Hal and ilie waler is \ cry shallovv , I he deep \alleys w liiidi arc
' Heiilej,'i'Ml lielis nil si.llie el Uie e,iil~ts 1111(1 islllllds ijf HelillJ,' Sell illlil vicinity: lillll .{••:,[.
See, .Vlllericil. \'el. \'. Ji, tiM,
■'Oil. i-it-.p l-.':i
"np. cit,. p. l:r.
<np. eit,. v l:.'s
"Bull. Xe. si. V. s. Heel. Survey, p. -.'lU.
1
' i ■
v'.n
m
' I
■'I'll:!;] i'i,i:isTui i:ni: mii\ i'.mi.nis. l'T,')
rciiiinl III till' iiiiiTiiir ii-.ii;illv mil rcic-hiim lo \\„- v,.,-,. h m.-n In'
iiilVrml I'rdiii lliisllial I ln' slmrcs of licriiii;' Sc,i aii' imu iikiic i'|c\ jilfd
lliMii llii'V uci-i' (liii'iiii;' till- pcisl -.MiciiM'iic pcriciil nf cru-iiiii, uinl tliat
llir >lii)ri'> 111' tlic (riiir (if Alaska arc iimn' 'li'iircsscii. Tlir ililTi-iciicr
ill llii- i-liarat'lcr cif the coasl line isxcry iiiarUi'il. a- ^liuwiiou ilu'
( (PM^I Mn'\ cy t liarl III' Alaska ; cM'Ii Im'I wccii llic ikuIIiwoI ami mmiiIi-
casi siili's ul' Alaska ri'iiiiisiila iIhtc is a ^timI ililVcicncr. Tiiis is
siisi'c|il ihlc 111 cNiilanal inn. Iiy sii|)|)iisiiin- irrru:iilaril ii's in tin- pcisl-
Miiii-cni' cli'X al ion or in ihc more i-itcmiI ii|)liri. 'i'lial Ilic n-iriit dc-
\atinn.ai Icasi, has liccii sonu'wliai iiTi'iiular is shown li\ |ihysio
Mi-aiihii- ■\i(li'ncc. In ciMiain pai'lsol' I hi' Tcriilory. iiortlmasl ami
so:itliui'>l rixiTs likfllif I-owit Viikiiiirni aluavs ihrif imrlhwi'sl
hanks, while in llii' saiin' iruions -iiranis likr Ihi' \'iikoii lirlwi'i'ii
( iirlf ( ily aiul till' roi'i'iijiiiii'. ami liiii'li ami lii'a\ I'l- iTi'i'ks. u liii'h
llou ihniimh level Hats of sill ami niavel ami ai'e tlierefiiie iininllii-
em-i'il in llieir chniee iil' direelioii liy roek sli'iielnie. Mow straiiiht
ami iiarallel to one aiiol hei- aei'oss llie Niikmi T'lats in a noil hweslei'ly
llileel ion.
'These |ieeiiliaril ies of ilraiiiai;!' {loint lo a ueiieral iiori h\\e>iei'ly till
in 1 his re^'iiill. It is also possilile. eolisiilel'llli; the e\ iileliees of I'eeelll
ele\alion nil the shores of lierini;' Sea. that llle estrenie liol't h wesleni
jiait of .Vlaska has 1 n ii|ilil'leil sliiilitly nioie than the sunt heasleni
|iafl. sii that the siii-Caee here has a sliiiht tilt soiitheast wanl.
Imleed, it is iM'obahle that there may lie a series of liroail. senile
wai'|iiiii;s nvcr the whole reiiioii. The axes of these war|iin,t;s may lie
taken as approximately parallel lolhe.Maska I'eiiiiisula. « hose t wo
sides show such ilill'ereliee in theuelleral eharaeler nl' theeoast li"e.
Some slleli w arpiniis as these may ai iiiil for 1 he eonrse ol' I he Lower
^'llkllll. lielow its ureal heinl the ^■nkoll appears to lliiu ill no uell-
marked. deep-eiil \alley, lull rallier lliriini;h an ii-reyular eonnlry,
where it si i a,u,i;les throiiL:li Hals or pliinues thnniuh narrou uiii-j;es of
1111 U'reat lieiL;hi. This eharaeler is in st rmii;- eoiii rasi wiih the I'pper
^■||kon aliiive the I'lals. where the \alley is \ery deep, well marked,
and pei'sisteii). .Mniii;' liie l.ower ^■ iikon, iiioreii\ er. t he hieation nl'
tlle\alleys. with respeet In llie present drain; .:e. sllL:i;e-\-^ that the
ri\ei' system may have been materially altered in roiiiparal i\ ely
reeelil lime. Til is w as espeeia I I.V IH it ed ill llle Inwcr Kaillparts. It
may lie. Ihel'efnre. that the Nllknii nriuiliallx Unwed strailillt nnrtli-
wesl intii the .Vrelie ( »eean. and thai, in e(insei|llenee nf a uelieial
siMldieasI till nf llle re;;ioil mil'thwest of il> pl'esellt InWer enlllse. it
aliandnlied its aiieielll eliamiel and fniilld a wax snlllliwi-l to the sea
aloiiji' the axis nf tilliiii;- Ihrou.uli the smaller \alleys n( its ow n Iriliii-
laries and those of ol her si reams.
"JT6 (iF.OLOfiV OK TIIK VrKoN (inl,l) DISTIiK'T. ALASKA.
RIX'ENT \VARl'l\(i!S AS SlIOWX 15y DR MNAOE PKCl'LlAKITIEs,
I'.y ll.\iioi.i. I!. ( iiiiinuK II.
\i.\-K.\N iiiiAiNAi;i: As ll,l,^•^^liA•|'l■'.ll iiv imutvmh.i: iiu'kk.
(Ii Id i-iil iiSjK ■■! nf ciiiiiil iiJ. — WHiXr l''(irlyillil(' (reck llic V.-llli'V of
I lie ^' iikim is p'iicrall\' luiiTiiw , aii<l cniilliicii licl ween Nlccp, ol'icii |pci-
[icinlii'iilar, walls. 'I'licsc r<'si'iiil)l(' I lie arlil'K'ial walls nf a lorl rcss,
anil 1 III' early cxpliircrs I'alJod tliriii ■" Kaiiiiiarls." a Iri-ni wlili-li lias
citiiic iiilii .i;i'iicral use, so thai \vc ha\i' tlii' rppiT ami l.nwcr Kaiii-
parls of lilt' \'iiki)ii, ami also llic Hain|)arls of tlir l'iiri'ii|)liif. \\ an
I'li'vatliiii of /)(M) foot, tho stoop sliijios nioi'^o iiilii a lahlolam'. almvo
uliich auaiii I'i.so niomitaiiis to a lioi^iil of J.."ioimo .IJiimi fool aliii\o
ilio ri\oi'. 'I'liis is llio yoiioi'al clianiotoi'lsl io tupo.urapliy of the i;olil
i-o^'ion of iiitorlor Alaska, a iiioiiiitaiii iiplaml ami a lowoi' [)latoaii,
iiiti) w liioli t ho siiialli'i- as uoil as llio laru'or st roams liavo out sliai'ii
valloys.
Aflirilii (if For/ 1/ III ill Cnck. — On {•'orlymilo (rook tlio uhsorxa-
tioiis \v(>ro fnllor than on anyotlioi' si roam, ami sinoo ils ilrainauo
liasiii shows rortaiii ]iooiiliart ios pari ioiilarly woll. it may lio takni as
an oxainpio of .\laskan ilraiiia,i;o. .Vt lliomoiiijiof l-'oriymilo ( rrrk
a llooil-plain . to .'! miles w iilo has lieeii formoil liy the eomliiiieil
erosion ami ilopositioii of this river ami the ^' nkoii. In this plain,
aliont •') miles soiitliwos' of I-'ortymilo post, slamis ;iii isolalod reiii-
iianl of the iiplanil in the shape of a prominent ooiie. arisini;' ."lun f,.,.)
alio\e the nonei'al lo\ol, from which l,ieutonaiii Schwatka. in Iss:!,
oallotl the st roam llowinji' alonn' ils base 1 ho ( due 1 lill K'ixor. .\Imi\c
('olio Hill the \alley of Fortyniile hoeomos ;i oaiiyon. often with ]ier-
pondieul.'ir olilVs, I honuh the u;oneral annle of slope is perhaps ."lO .
The liranelios of the main stream low in V-shapeil unruos. wiih -i,
iiioileraloly hiuh .i;i'ailioiit, ami linil oullel tliroiinh uato-liko hariiers
fornieil by riiliies parallel to the strike of the rooks. When those
Inanelios llow al ris^hl an.ulos to the strike i heir channels are narrow,
their .urailients sloe]), ami their tributary ri\ niels lluw parallel to the
strike. When the yonoral IremI uf the stream is ilian'onally across
the sti'iki' of the seliist. the water altei'iiatoly Mows parallel willi the
strike ami cuts across it at ritilit aiiiilos. Syminol rieal riil;;es are
I'ornioil al the points of conlliionee of the main creek ami ils tributa-
ries bylhe intorsoel ion of the slopes of iho V-shapeil \allo\s ( see
li.U'. -II). The fall is eonsiilorabli — on the main crook nearly In feel to
Iho mile. The oiirrent is thoi'oforo stronn'- from s lo lnmnes per
hour — ami this, touotlier with the shape of Iho valleys ami their rim-
iiodnoss, is evidonoo that Iho ilraina.uo is in its youth ami that the bod
is now boiiia' doeponed.
llii II III- II III mill (/, —There is. howo\or.an abnormality in the otlior-
wi.se youthful-aii[ioariu,n- l-'ortxiiiilo Creek, for. consiilerinn the swifi-
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.ii'"i.Ki. II ■ uKi i;nt \v.\1!:'1m;s as shown i;v iiiiAiN'\(;i'. I'TT
lic>s 111' ils ciiiTi'iil ;iMil 1 he liariDWiioMir il s cliiiniicl. uc >li(iul(| i'\|icc't
i(s riiiiyDii (MMirsc 1(1 111' Nliaiulil; mi iIh' cipmI r,ir> , il iiifainli'is anil
fiiniis ii\l»>\vs likf a si I'l-aiii llnw iiii;' 1 lii(iiii;li an u|irii \ alli'V . I lif appai'
fill iraMiii iH'iii'^' thai llic |ii'csciil \all('\' l'iillii\\>a liiii' ol' draiiia;;!'
]iri'\ iously (Ictcniiincil ; llial, in nlhcr wiinU. Ilir iiicainlciinir lialiil i>
inlirrili'il troiii a lime wiii'ii llir slicani IIhuimI wiili |i.n> i;iaiii'. 'I'iic'
oxliciws. wliicli arc li'cnci'ally rniiliiii'il lici \\ ecu ran,\ mi uails, all hiiiiy;li
C'r<i.--iiiii in soiiii' cases lias aliiKist clesirdvcii ilie canynn lypc, are
locally calU'il •' l<inks,"" Uniiinii lamls dcciir mi P'orlyiiiile ai Narimi^
Itiiinls. hill lliesc arc sliiilil ly c\anL;i'raleil un i lie nia|)(l'l~. \l.\'l.
\l.\ll. |). ^ilS), I'm- at (inly one jilai'c ilo Ilicy exceed liall' a iiiili' in
Km;, :,ii.— .IiiiHiiuii ot' l"iii'ty;iiik'Cr«'<-k ami Suiiih Cri'L'k.
width, 'riic.v do not roriii a coiit iiinous flood-iilaiii of any oxtiMit. siieli
as is I'ouikI on a stream (if low carrying power; hut aie usually caused
liy the ovoi'lappinir of bars on the curves of the crc(d<. or. in some
cases, by dciiosil ion in (|iiiet ponded areas above natural dams.
'I'lie trail lo the lidld dii:-.!,dn,us of {•"ortymilc district leaves the main
creek at the mouth of .Moose Creek, and at a <listance of J miles
climlis .Moose Creek Hill by a very abrupt ascent of ii'in feet in a little
over half a mile loan elevation apiiroxiiiiately \.'M»i feet above the
sea. Here, from the point of the hill, a rather conline<l view seems
to .show all the nei.nhborinii- hills at the same elevation: that is to
say, the eoiiiitry ai)iiears to have unci' been basclevelcd. 'roward the
MM.
■J7H (ii;ui,(Miv oi' Tin; yikdn i.oi.d ni>i"i:iir. Alaska.
sciiitli ilic yroiiml ii-i'> i;ciilly, iiml iH ;i poiiil J iiiili's I'lii-t licr m \\iil<'i'
I'iiiiiri' III' vision i^' iililMJiicd. Willi ilic --ii iliiiii; oiil ni' iln' inpd^'-
i'ii|p|i\' wliirli ii (listaiit. view all'iinls, il is seen ilial iln' I'lPiinirv al iliis
clcvaliiiii is iiitl a triilv Ii'M'I plateau. Iml has lalln'i- ilii' asiicci n\' ,i
liroail. shallow valii-v. cNlciKliiiii to Ihi'wcslas lar as III" eye can
rcafh. Till' Incadlli nl' this i|c|iri'ssi(iii is a|i|irii\iiiialt'l\ s uijh.s, Iml
il iiairous ami ur. iws shalhuMT lc)\v.ir<l I he head <>( I In- p resent si i'imiii,
ami iiidi it l'"( III >■ mile ami its t rilnilaries have elehed eaiiyuiis. while
aliiivellie level rise liiw iiKiillilaiiis. w hose rounded oiillliies foini .1
ureal i-ontrasl In the hiy:lil,v aeeeiiliialed minor toponraphy.
At many olher points the older \ alley was oltserved, notalil.v Irom
Iheeiid of a ridu'e jnst above l''ianl<lin (Jiihdi. Al this point it lia>
decj<'a^e(| i,i width to J miles, l-'rom its ele\ at i<in here, as compared
with that at the Icjcality Just dcserilied. its slope must lie nearl\ o."i
I'eel to tile mil
Ii.
ivv niindi ol' this liradieiit isliial of I lie oriuinal
St ream and
how iiiiich is chie lo later warpinu' il is iinpiosilile ii
1)111 al present the ^I'ades of the older and yoiinncr st reams dill'er; so
llial I he I wo may li< neelvcil of as planes vviiicii approacii each oi her
tovvarii tile iieailsof tiie valleys. 'I'lu' caiiy<in walls, t iierel'ore. deeri'ase
in hei.iilit as one ascends the stream, Iteinj; iiartdy .S"!!! feel iiiuli al
I''ranixlin (Jiilcii. and <lisappearini; cntiridy in liie \ icfiiily of ChicUcn
('re(d<. near the iiead of theSonlii l''orii. 'i'lic accompanv inn' pii.v sio-
urapiiie mapiri. .\ l,I\' ) siiows the limitsof tin- older and .\oniiucr
\ alleys, allhniii,di the line of demarcation iiinsi not he reirarded as
alisointely ai-eiiralc.
The facts noled ii|)on l''ortymile (reek are lo lie oliscrved 011 many
(It lici' streams, 'i'iie iip|ier plateau is evc'iyvvhcrt' ntiliceahle. and iiiioii
examination il could donl)tiess lie dixidecl into maii.v In-oad \ alle.v s
exleiidinn' lia(d\ into Ihe nioiiiiiains with tiie same ramilications as
tile present drainafi'e.
77/' jinsiiil riillf 1/ <lii( lo iijillf/. — We liave. tlieii, two ineonipleie
eyeles, tiie older ropreseiilcd in' liie valleys in which ihe streams piii-
siied iiieaiidei'in}>' courses. .Vltlioiij;ii tiieir chaniuds iiaii not lieeii
de,tri'iided lo l)asc-lev(d, liiere must si ill liave lieeii some fall, and the
topo.ufapiiy. wiiile less pronoimced tluiii tlie present, was not vet
featureless when elev at ion look place. 'I'lie streams ac(|iiired new
activity by I lie lowerin.u: of their out lets and liciian the cuttinu' •■( Ihe
present ttorii'cs. i>nt Ihe uplift was not rcvolut ionar.v. as is seen li.v
tile fact that the streams now pursue the same ^'eneral courses which
they held previously, the main drainaire lines at least not hein.ttallercd.
lllVl.lts .\s .MKAsrUKS Ol- W.Utl'INo.
I''or reasons alread.v .i^ivcii it is prohaiile thai llie ciitl iii.ii'of ihoe
canyon \aileys was aeconiplisiied niaini.v in i'lioeeiie time, and that
snliscipieiit to th(> cuttiu.ii' tiiere was a brief sul)iiiei'geiiee, followed by
an elcvalioii uliicli is probably still in progress. .\s a result of this
»,ii:'
44
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!,•\^ I cli'V al idii till' (liiw n-( II
Itiiii;' 111' th
Mili'cllc \ ,ill<-\ -. w
liirli
iiilriTii|ili'il li\ iIh' >nliiiirrL;c'iiiv. has 'i.'fii i-cih'u .mI, TIlii ilirn'
oscillat iiiii> were cxcryw lii'i'c llic saiin- in n-lal inn in iIh' sea li'\i'l is
imiirdtialilc. I"'', in <-\i'\-\ iiiii\ nuriit nf mi i'iii'ii-...^ciiic iial mc i line
a IT ii'iTiziilai'il irs. I lie icsiills 111' w liicli aii' m'c-ii in I ills, u ;n']iinL;s. ami
niinnr r<il(ls: ami llicsi' dillVi ri-ciu cirilinary iiliralioiis in hrin;:' ii|i"n
such a lii-i>ail scale Ihal 1 lic\ :iic mil ni'iicrallx \ isililc In llic nliscrv ri',
c\ccpl liy cipin|iarisiiii nf d.ila c\l"iiilin,u ii\cv i-uiisidcralilc arcns,
(crlain criteria can lie used I'di- (Iclerniiniiiii' iln' existence. aniMunt.
ami ilirecliiin of such ilisi ui-'iaiiccs. Iml oli\ inusly these crilcria niusi
he (Iill'erc!ll it. ililVerent pari s of 1 he llclil .
( )li Ihe i-oasl the fclatimi i if the iiplirieil slll'laee In I h ■ |nvscni
le\el Liix es an o|i|p(irl nnii.\ rm- ill reel i|>Mrisiiii ; in |Miit ions i,i tin'
Tcrritcir.x- remote I'nnii llie nceaii im -iich (i|iporl uiiil.x is iiilMrdeil.
Here the delails iiiilst be I'niiiid l),\' a carcrnl exaiiiiiiatinii ,<( the inpdi;--
1 hy a I'liiiipMrisDii of the previous cycle with ihal ol' the
llei'led li\ a liltiillj:
rai)li\' am
"I
presenl. for the drainaize upon a L;i\eii siirtace is a
ariiiiiLi' of that siirlai
'hcret'ol'c I hi' I iiliaril i
if the present
drainai.''e .unc some hints as to tiie irregularities " I he nioxeiaeni imw
actually in pro.ui-css.
In those streams which are i'apidl.\ deepening i heir channels llie
elVccl will mil lie soappareni as in I hose u hich uandi'r in open \ alleys
near hasedevel; hut e\ cii ihe former may show evidences of tilt in
the \alle.\ topo^raph.w l-'or instance, a competent stream u| a
tilted sui-raee will perform ;^realer Work upon the lower side of the
tilt than iliKiii the ujipcr. am
1 the resllll will lie c\ idelll in dilVerenl
ways. Streams Ihiwin
those Mow in.ucipiiosile to it are ret
e- in the direclion of i|e lilt are acecleratcd ;
ai'ded. and the result is the develop-
ineiit of au'uiisymmetrical ilraina,i;-e system. !• iiitliermorc. streaihs
which How al rii;hl au.uh's to ihe tilt will tend i > miur.iie to the \,<\\rv
side of Ihe vallc.N . while tho.si' llowin.ualoiii;- i! pcrsisi in their ori-imil
hat the svstem will he not only uiisymmet rical. hut the
iiirse. so t
trunk and minor streams will li.ivea rectanmnar iiiU'ra
lerarraimi'menl.
Those hranches whieii I'ow
down the tilt will ha\e an advaiitaui
otlier conditions Ih
inn- Ihe same, ovcrthose llowinu' aua'nsi it. so iliai
if uiiliiudered the former will divert llie latter in ad.iaccnt sysleiiis.
Cases of recent or immiueiit siream caiiture an' therefore of -n-at
\alue ill iracini;- irrciiiilarilies in a recent uplifi. 'I'lie ivsnlis of
irre^:uhirit
meiil of drainau'c a
lies of ujilifl. then, are to he disi-ovi
red hotll in the .iliLin-
iid llie latest iopoi:raphie iirodiicts of erosion.
Ill of the Vilkoii itself issii;iiiliealll.
Till r"A'o//. -'riiealiu'iimeii
character of its valley up to the pom
Flats has lieell descriheil ahove. Here it eiilei-
lit where It ell
ters the ^■|lkoll
iml, unhindered hy hanks of aii,\ coiisn
the old taki' country
l-rahle licielil. sliou~ a lelid-
ilso docs ils nrdn IrihulaiN. liin
h I leek, to swerve In ill
riii'lil and lo outlet, as tlii' older maps had ii. i
ilo Ihe Arctic 1 ici an.
i i'l
1 m
] j
il
I
2S0 Gi;nl,()(iV ()|- IIIK YUKON (iOI.M DISTI.TCT, ALASKA.
'i'hri'i' iii;i\', imlcrd. liM\ c 1m ,1 \ <'i-y cnrlv ciMiisc in tlii>ilii liori
\»liic-li riirlhi'i cApiiiral ion .-iliini;' tlic northern !i<iiiiiil,iiyiir I lie l'"l;ils
iiii;;lil disccivi'i'. liul if sMfli n one i'\i-^li'il il niii>l li;i\ <■ anlcdiili'il the
inlcrlDr lal<c>, lor llu- millcl ol' \\ii- lake jn'i'idil was, as imw . li> way
ipf llie l.invcr Haiiiparls. 'riiis, licini;- llie lnwcsl ])(iini. iletciinincil
till' (iii'ccl i(in in which Ihc ii\ci- llowccj al'lcr Ihr i-i'\i\ai of slrcani
ai-ii\ il \ ami ilii' ilraina^i' of I he a nc it 'U I lakr. 'riironi^h llw l'.'pi* niih'-"
of ilii' Vnkoii I'lais ihrwcik licini; ijoni' upon Ihcviulil oi-porihci'n
bank is irn'a11\ in r\i'c-sof thai on the soul hi'iii. As an iiliisi ral ion of
this il is said ihai no Itoainian nascvcr lloalcd down thi lower \'nkon
mIoiil; I Iw h'I'l hank, for. I nisi i ilii' lo liic (Mirri'iil. Ihr hoal is invarialily
drav.n loward ilic norilicin hank. When ihc \a ley is iiii'lo^nl
hci ween raiKpai'is 1 lie icndiMicy low an I Ihc iiorl h is nol so nol iccahlc,
hnl il has been ol)sc;\ci| by Dall and oihcis ihal Ihcriuhi bank is
bciny' nioic \ 11;'! iron sly allai-ki'd all alonn' ihc fi\ crV conrsc
l-'tirl iliiiih I 'ml:. The main fcal iircs of P'orlyiiiilc. inclndin.:;- Ihc
older and more reccnl \alleys. hasc already bi'cn i|c>cribcil. I'or
|iari> of il-. course Ihc older \ alley seems lo be di.-'ii., nl n|ion .'he
yeolocical st riii-l lire. as. for insl:ince. fnnn I he N'lU'l h I'm-k lo 1 he inoiit h.
w iicrc. in general. 1 he di reel i mi coiiu'ldcs w il h Ihc si rike of 1 he i-ocks.
In ol her porl ions I he \ alley runs ai'i'oss I he i-o(d< si laicl urc. as bet ween
Walker I'oik and \orlh I'ork. Tin' preseiH slreama'so. ils course
beilii; direclly inhciilcd fnnn Ihc foi'nn'r. Hows in Ihc s.mih' li.isin al a
lower le\id. showiuL;' no preference Uiv eilher side of lh<' \alley. bnt
iHc.indcrini; bel ween t he moiinlaiiis. liisl iipmi mie side. I hen npcui I hi'
(tiller.
Scxcial larue slreams cnler from ihc norlh. the niosi im|iorlanl
bciiiLiO'Uricn (reek, w lilch di\ides a few miles ,il)o\ c ils nnnil h inio
Iwi) liranehcs. MowiiiL;- parallel with th main l^'iu'lymih', mie risinir
to the west, Ih" other haviiii;' its source iindei' a hiuli i;ranilc peak
known as '■ 'I'lic l)onn'."al ihi' east, 'riieic is a siiirui'sliun in this
jjeeiiliarily of a dixersion of the east ami wi'sl heads of ( )"r>i'ien ('i'e(d<
toward the stniih. There are also examples of probable divei'sioii in
olher h)calilies. In all of which, howexer it must have oecnrred pre-
vious to I he latesl uplifl. P'roni I he south side of l'"iu'lyinile I he I rilm-
larics ari' miicli fewer and smaller than from the other, ''anyon and
.steel creeks hcinv.' 'he larncsl ; ihe conlrasi, however, is probably due
as much lo the .~nnill drainace area belweeii ihe main creek and
W'.ilkcr l-'ork as lo any ol her cause.
,\b(Uii ."lo mile-. I'nun ils nioiilh. l*'orlyMulc divides inio Iwo main
bram-hcs. 1 )f ihe Ndrlli T'ork lilllc is known, except thai il ha>!l-
soiiri'c ncai' the headwaters of Itireh (reek and Mews in a nciieral
direction eastward. 'I'll' Soiilli I'm'k. on Ihe other hand, has been
Well pros] icil from ihe liasi.i-likc ari'a ai its heail to its jnnctiiui
w i' h I he NiM'l li I'l'ik. so that its leal 11 res are much hel ler iimlcrslood.
.Several small tributaries <h)w into the main creek lid w ecu Walkei'
^
fi....|,,,i, 11.1 KKi ENT \V.\i;i'IN(.S A^ J-11()\VN |•.^ UKAIN M .K.
■J 81
l''oi'k ami ilii' Niiiili P'orU, (if wliicli ilir iiici>i iiii|iiirl,ini . Iicc,iu>c iliry
arc till' i)nl\ ones upciii wliicli plai-cT iiiiiiiiiL; I is ih-im'cciIccI licyniid
llir --la.uc 111' |ii'i)spcci iiiii'. arc l''fankliii (iiih'li and \a|iiilciiii CrccU.
Ildlli of llicsc creeks sJMiw asyianielrv in I lieir \ alle\ s: ami in initli
ai'e sleep side:- al \\\i- sonlh and a i 'e L;i'nl le rise inward ilie nnrlli.
{•"ra:!kliii (iuleh is a strike \alie\. and ilie niiuiraiinn ••( ili- sireani
liaxinu' lieen d.nwn ihe ili|i 111' Ihe roeks. llie siinlli side i^ a strike
riduc "illi ii\erlianuin,i;' (dill's and |eiii:e- -a u'reat ennlra^l to Hie
sinniitli. eas\ sUipes cif the iKM-tl' side. 'The npper and Iciwer parts (,|'
till' valleys are wididy dilVerent. ,"''i'(in-li the lewer part I'rankliii
(Inleh has enl a eaiivoii. lint m^arc^r I lie head the \alle\ lieennies
hiiiadc'r. al an elesatimi eDrrespnndini; with that nl' the nld \alley
npnn l-'orlyinile in this \ieinity. cil' whieli it rornied a part. 'I'liere is
in tliis pdrticin, tun. a lelldeliey nl' the ereid< In Ihiw .ill the >.intli side
111' its \alle\ . Ill Nape il I ( leidi and many other irihiitariesdl' I'orty-
lllil,. thi' -^iiaie lelldeney was iiliser\ed. as also apoll a few of the
ei-eeks of the Sixty mile drainage, of whieli .Miller and t.laeier creeks,
in I'iritish terrilory. may lie ipioted as examples. ( >n ihe latter two
lliere is a \fvy evident asyiiimetr> of the \alley. the sleepesl side
lieinii'llie soiilK. 1 In Davis and I'oker eiecdxs, whieli head in the Uald
Hills nearly against .^Hller and (.laeier and iinile to piriii W.-ilk r
|-',irk of l''orlymile. Ihe lemleliey. if il exists, is mil m.lieealile.
Mi.ssKiii r,v' /.. -.Mission ('re(d< eiih'rsthi' ^■|lkon al a sharp elbow-
heiid of Hie ialier alioiil .">o miles below JMirl y 111 i le and on the .same
>ide of the river, .'i'liere is a wide stretch of linttolll here en the sollHl
side of .Mission Creidv i iHi. liiil above this rise li ills the tops of which
•ire at an (devatioii of ."iiin feet above llii' waler. apparenlly indiealini;-
)i\ Hie evenness of their <'iesl line an ancieiil valley whieli extends
l.a.d< for several miles into Hi- hiii'li nnnmlains. This is part of Hie
-.1! e ,iearly levcd nplaiid remarki'd all through the rjipcr Kain|iarts,
',,i;e'!'- probably represcnls Hie old ^■llkon N'alley.
!;• Mission ('i\-ek sysli'in is>lecidedly nnsymmel ileal, both in 1o[)ol;-
1-, phv and aliunnieiit. Vov the last jiarl of its iMini>e Mission ( ivek
flows lliroiiuh a coiinlry which rises I o Hie s<iiith very ucnlly t.iwanl
the hii;li hills ill i he dislaiiee. Hie unnind on this side b 'in;;!! swaiiipx.
nioss-eovered. sh pin;; plain, drained o\ I'mir lar.ue cif eks, .\inericaii.
Wolf, the head .if .Mission, and aiioiher sill farther ,.i Hie w.'sl. On
the north, steep (dill's and slop.'s of over :|o y\>'' fr( iii the stream l)e(l
1,1 a heliihl of somelimes .Sim feel, fonniii^' a \ erilable wall wliiidi is
l.r,.keii in Hie dislance traveled oiil.v b.\ diie small creek and a lew
unllies. In oilier wor.ls. erosion is. in the main .'reid.;. piiH'C'din-
more rapidly ii|ioii the iiortli. so llial the slream is .'row.!...! toward
Hint side of the v;ille\ ; and the lira iiiaiic is reel aiiiiiilar ami sided.
.MiN.'.ilers are fre.|iieiiH,\ sc-ii iijKiii Hi.' Lure tributaries. Wolf and
American crc.dvs. as well as n Hie main cre.dv. They are, however,
more prononneeil iipnn Hi.' lalier. .iiid yd, lhroiii:h all ii- waiiderin-.
Mission Ireek holds its iMiiirse closi> to Hie iiorlh iiaiik.
e
2^1' (ii;()i.(i(iv ipf riii: vikon um.n Disriiicr. ai.aska.
'
; 1
i
'' ■<
1.'
1 1
:r :|
M(/Niii,l,- (iii'l I liinh r ri-i I h's. - '\'\\r MyiKioU system iil' i| i-.iiii;i;:c. in
llic l,<p\\t'r l{;iiii|iiiils rcifiiiri of ilic ^■llk(lll, sIkiws- in ils iiliiiiiiiiiui
the s.iiiic pciMiliaril ic's ohsci-x cd in Mission ( 'n-ck. While I he main
ereeii llows uesi iif iiorlii. ils lai',i;i' liraiieiies lliinler. I.illle .Mymi(i|<.
an<l Kuliy (reek- enlei' al riulil anules to il : thai is in say, I liei'e is a
tenileiiey lo (low ainiii;' I wo lines. I lie one east and west, t he otiier nm-tli
and siuiili. Soinel imes. as in the ease of llnntei- ('I'eek.a lirani'li
(lows Cor a part of itseni: ■ ,• lonu' one ol' I hese liih's and roranothci-
part at ri.nlil anyh's to \\: n I '' as eonld lie le,ii'ne<l I he adj.-ii'eni
IlessCreek system also liasi. it. Mowing' eastward Tor the liisi
few miles of ils eonrse and then idini;' sipiarely to lh<' niM'lliuesi
and llowinul'or l-"i miles in t hat clirei-tion until it mi'eis 'rrouhlesonii'
|{i\ ei-. ;i not her u esl Ward llowini; si ream.
■Jlit iiniry ihronLih whiidi Mynook ('I'eek Mows is a plateau, into
whieh I he reeent eiiti ilia- has progressed sonii' III "I or run I'eel \ ert ieally.
This plateau is formed of rocks which dilTer in eharai'tei' and ha\c
\ aryiiii;. oft en I imes \ery steep dips: it is, therefore, a plain of crosinn.
The ciiltin.u' iias been sharp, prodiicinu' i-im'i;'ed \;illcy walls; lint at
the lioltoni of I he \ ill leys I here is a arax el deposit I .") to I'll feet I hick.
This deposit extends as a liench or tei-race l he w hole length of II iinlei'
(reek as fai' as I raveled, and is seen also on the lower part of .Mynook
Creek, risintr uradiially in .section up the creek: into it the creek has
enl a lren<'h or small uorue somelinies i'.") feet doi'[). The uravcl tei-
raee marks an older \alle.\. which, if restored, wonld he a little over
one-iinarler of a mile wide. In the latest cull inu' 1 he si ream has not
kept to the middle of this valley, Init nnvaryinuly holds its coiii-sc to
the norl Ii liaiik.
.\ flirt her st rikina peculiarity is, as upon Mission ( feck, i he alisenre
of minor drainau'e from the iiort h. In the whole distance i raveled on
Hunter (reek the north hank ]ireseiits an unhroki'ii wall except al ime
point, where an insiaiiiticani wali'reonrse e.vtcnds back into the hills
scarcely :.' miles, 'i'his is rallicr a foully than a creek, and re|)resents
the very latest product of erosion. The maineri'ek meanders, and in
its swinjjs it frequently <Mits for short distances into ihe n'l-'ivels of
the middle ^■alley: liiit it is heina straightened liy fieipienl eiil-oH's
in th(> oxbows, and here aaain is a remarkable fact. I'm' th(> eiil-olVs
are formed only on the north side of Ihe valle.v : in no single case are
th(\\- made at the south. Tlie universality of this t hroiiiilioul Ihe
drainauie system is indication that tliere is generally an ace deration
in the portion of the curves llowinii' mu'thward and a correspond iiiLr
retardation of those llovvini>' toward the south. Tin urse of the
creek is evidently beiny si raiahtcned by the cultiiii;' oil', but with
I lie one-sidcdness of I he st rainhleiiini; action there follows a migra-
tion of the vv hole creek tow an I t he north. (Sec Hi;'. -\.)
Ilinli Cmk. — The topoaraph.v of iherenion ihrouah which lUrdi
I'ri'ek Hows is diverse. The lower hundred miles is a ecuintrv oi'
h
....i.Ki.M.l i;r.(K\l' WAKl'lM.S AS slldWN l;v DKAl \ \(;K.
:.'s.".
nil I'i'lirl. Il;il 111 111!' I'yi'- a MId-'-chv rri'il, I i iiilii'l'i'il |iliiili. III vvliii'll
s\Viiiii|is mill lakes an' nl' i'iiiiimhui nciMirnMii-i'. '\'\\\-~ i- kimwn a->
llii' Niik.iii l''lals. ill wliicli Ilic ^■|lk(lll ami its t i-itiiilaiv. liiicli < in^k.
tliiw parallt'l in iliri'rl imi ami arc sr|iai'aliMl li\ niily a fru niilc'- mT
swamp. Kisilii;' In a iiiMLjIil nf -"ii"' I'rd almvc lln' slri'aiii-. ali'l I'miiii-
iii;;' an i'srar[niicn' :l nr I inilrs scnil liui-sl dI' ( irrli' ( ii \ , is i lir -..■ihk.
i'l.'\ali'il plali'an imii'il in ilir uIIht ilisi rii-ls, a iinrt iiu ai'l -|iiir ni'
w liirli is rrusscil liy I In' 1 rail In I lii' i^'nlil ilit:':;ini;s, A Her .1 ,iiiiiini-,\ nf
1") mill's I'riim ( irelr ( ily almin' the I iiiiliereil Inp nl' lliepialeaii Mie
I ravelcr eiinies hy a smlilell ilescenl In liireli (reek.
A( this piiinl, where 'rwelvemile Caehe (a mail hniise I'm- miners)
has heen eslalilislieil. the creek riilis lhriiiii;li a i:ap. whose liiMinilim;-
siilcs, less than - miles apart, rise in sleep \\alls Inn leel ImliIi. I'n
ihusiiiilh nC ihci^ap the \alley .iLiaiii spreails mil inin an apparcnily
iffi (if ! m^ilkmWWi II
''"iim0'-'^
l-'ll, -.'I N.ll-tll-ill.- .■lll-'ilV illnl .l.-.TIr.i ]l|c illMl.'l- "H lllinlrl- C 't k
lexi'l sirelcli n\cr 4iiii sipiarc miles in area, in these liireh ( reek
Mats the creek meamlers in the iiinsl iiitrieale manner; nvlinws are
ri-eipieiil. ami lliere are several examples III' I'nrnicr uamleriii.us in tin'
nccurrenee nf crescent -sliapeil la,i;nniis wliich at im very ancient dale
rnrmeil parts nf the meamlerinu' si ream eniirse. lint have since been
cut nlVanil remain as lakelets. These are especially iierniis in tho
vicinity nf ■i'welvemih' Cacli. . ■i'iiere is still anmiier kimi nf lakes,
e-cncfallx larger than llie la;;oniis, wini.se nnHine is mnre nearly eircii-
rarami wliusc iariic area shows liial they <'an iml l>e accnmiteil for in
the same wax. ' >f ihese .Mcilicine l.,-iki' is an example, ami it seem,
either that lin'\ ha\e been can.^eil hy a verv recent ilammiiiL;- <>t' tiieii-
nutlets nr that they arcreinuan's nf lar-er exiianses nf walcr uliich
fnrnierh' ncclipicil I he area.
Kviilencc has alrcail.v heen uiM'ii m slmu thai the \ iikmi i'lals
cnuutrv was at mie tiim upid hy a lake it seems alsn. Inmi ihe
" "Sill
S'
m
i,
M
■'is 1
Hi
iJHli
I ant' I '
mi
:.'84 (;i;oi.(i(iv of tiif, vinon gold uisiuicr, ai.a.ska.
Hill Mil' nf I he ilc|ii)sits rmiiKl ill tlii' I Jircli (reck lljils. nliii'li ;iii' .iii>t
siii-li ii> Wdiilil he laid iIdwii in qiiifl walcr, I li.-il llicrc was licrc alsd a
lalvi' ii\ IT 1 1 II I s( I iiarr miles ill area, a IK I that in tlicsc sinalliT liiMlics df
waliT «!■ Iia\ I' I hi- last siai^fs nf ilir ilraina.ii'c ami laxini;' liari' of iIk'
liiiiluiii. Uy the ilrainiiiii- i>\' the lake M'l-tical ccirrasiipii was Im'^hh,
liiii I he tci|ii)u;ra|)liic ri'siills nf I his icci'iil erosion dilVerin ilill'ei-eiit
parts III' the lielil ami fail iiat iiially into three (livisions. In ihe
lower, ihal ie|iresenteil li\ tl nt'et at 'rwelveniile C.-iehe. \erlieal
<Miiiasion liei;an iiiiiiie(liately with the iipliri. a n'oru'e was e\ea\ ateil,
a nil 1 he \ alley Ik ■came sharp V-shaped. I! ill in the middle port ion it
was iiiil until a i;real part of the water in the lake area had lieeii
draiiii'd awa.N t hat \ crl ieal eorrasion heuaii. In fact, it may lie said
that it is at present onl,\ liei^iniiiiii;' to he an imiiortant factor in (he
erosion. Tlie st reams w hieli entered the hik(> from tlie iippci- division
had I lieirael ixily inereased almost immediately, and Iteiiiinlhe higher
t;uri;e cull inii' that is seen at the nioiilh of I'.oiilder Creek aii<l ahovc.
Ileie the streams cut lhroiii;li uravel deposits, which were lai<ldo\\n
dir'li.U' or soon alter the period of I he lake's existence. I liese heini;' in
]ilaces Jii lo J."i feet thick, lint u'cnerall.N' tliinnin.n' out toward the
heads of ihe streaiiis, A short distance aiioNc, the mountains lieniii,
the \alle.\s close ill and liecome narrow "/-i'laiMMl nulches: but e\ en
here and for some distance toward I heir source the former \ alle.v can
be traced, an example beiii.u' Mille- t'reek, where there is a terrace, as
lias been ah'ead.\' said, exloiidin.ii' some (listanee bel'ore it becomes
iiidlstiimuisliable.
Ill ali},'niiieiit IJlreli (.'reck ilraina.ue is iieciiliar. ^^'il]l its iiiaiii
braiii'h, rreacher Creek, it incloses a sireat pear-shaped area, of
which the lower liiindre(l miles is the stem. I'pon close e\aiiiiiia(ion
it is seen that tlie whole s.xstem can be divideij into tw(. well-delineil
classes, the li'.si coiiiprisiii.i; such erei'ks jis r>oiian/a, .Mn.er, llou'em,
Boulder, Mi'slodon, and tlit' middle part of Itircli, ail of which, dis-
I'c.aa I'd i n.n' ; Heir minor meanders, flow in a u'eiieral direction northward
and acrc-is llie St rike of I he rocks. In the s(>cond class are the head
of lii'di Creek, Xorlli I'ork of l!ir<-h. North and South forks of Harri-
son, ami also ihe main Ka.ule Creek: these Mow in u'ciieral east and
west, parallel to the strike of (he ro<d<s. and at ri.nht an,i;les lo the
former class.
Ill' these (wii sets, the streams llowinu northward are performini;-
liiiich greater erosive work than the others al ri.yht aii.ii'lcs to I hem.
Tlie clilVs a( their head are beiii.u; raphlly broken down b.\' (he ai'tioii
of frost ami ice. ami the iiiatoriai lliiis supplied is easily (ransporled
b.\ I he si reams, so (hat I he divide is bein;;- pushed southward. As we
.should expect also in a miiiratiiii;' di\ ide of this kind where the two
stri'amsare unlialaiieed, there is a very evident tendency to a di\cr-
si on of ( lie east ami west s( reams into a iiorl liward course; for exam pie,
3Iaslodoii is on the point of capt uriiiu' tlie headwaters of Uarrisou
i( iinil IM'.CKNT \V\H1'IM,S AS >II()\\N IIV 1 .1; \IN \(ii:.
■'X'
Creek: amiin. I'lirlllel- In llle ea>t. IliiL;'e|ll (reek i» luWerillL: Ilie
divide l)el vveeii itself and 1 lie Ncii-lii i''iirk of I larrikin, ami will in 1 iuie.
if iniinlerrupled. sneeeed in leadinir nil' ils \va1ei'> liy a nearer idule
ti) ( riMiked ( 'reek.
In Ilie (i|)|i<isit ioti 1)1' ilie Iwii sets liiei'e is I li ri)nL:liiiul a reeiaiii;ular
arraiiuenieni \' li is in pari iidiei'iled, a'~ in Maslnddn. Ilarri^nn,
and (Mliei- erecd<.s; lint il is alsn <'\iilenl npnn streams uliieli are ihe
latest pi'dduet 111 (ll-ainaue de\ elnpnienl sinee llle i;rea1 lake- di--
appeareil. I''.\anii)les are (rcinked (reek, uliieii llnw s sum li mT ,a-i
as far as .Me<lieine Lake, whence it lunis si|uar(d>' tn the nerih. an I
the minor liramdies. (^Miarl/. and .Mlierl ereidvs. which, risiir^ in I he
Cra/.y Mminiains. eiiler iiireh (reck al rii;hl anuh'-. In i hcse
yoiniii'er streams, owini;' pcrhajis lu the shalhiuiiess nf ilie \allcy-
whleh theyha\(' cut . mi select i\c tendciic\ df I he si ii-an; channel is
observed. However, in olhei- valleVs of ihe ( rnokiul (reek drainage
a decided leiideney low ard the iKM-thci'ii hank wa--eeii. In I'lireii-
pinc (reck vallc.v. for :l miles from its mcinlh, iIm- -irciin icniains
closely under steep liliitl's at tile north side, Icavin^ia hroadly slnpinLT
valley at the south. In tiu' saiiievvav. in the last :i miles of .Miller
Crcidv. a terra f I"' lo i^'i feet is ohscrved. sloping:' ,L;radiiall.v in the
ridu'c al the s(nithwesl, while upon the lefi bank ;he slope lo the
creek is abrupt, with frci|nent binl'l-, (Mi these iwocreeks and on
.Mastodon, whei'c the Icndcney is iioi so well shown, ilic a-vmmclry
iscaused liya migration of lliecre<d< cut ircly indcpendeni of tlicueo-
loii'ie structure, .Many c're(d<s llowiiiL;' alon;^' the sli'ike ol' ihc rocks
south id' the main divide of the I'.ald ,Monntains have uiisyinmi't I'ical
vall(\vs also, but the one-side(|uess in these has becucauscci bv migra-
tion down the dip of the uielcrlyini; finiiial ion, and the sleeper -ide
is. c.vccpt on l'!a;;le (■re(d<. upon ihe --outh.
> M-i;- ol \>v\iMi;i i!V Ml ■,ini,.\.vi--.
We have. then. lhrou,i:li ihi' interiiu' of .Vlaska, a rev ivi'd draiiia.tro
sliovviii.u' certain peculiai'it ies indiici'd in the lU'csciil cycle w liicli are
not conliiii'il to one erecd< or system, lint arc> to be found in I'mdi and
evcr.v (Hie of the systems, 'l'hes<' are a ccrlain delinite ali.iiiimcn: and
an unsymmctrical topo.iirajili.v, and their e\iei;siv •ciirience seems
to demand for explanation some cause operative alike over lii-cat
areas. We have already slated one i;eneral i-ausc of pi-culiarit ies in
draiua,;:'!'. and by jipplyiui:- those ]naiiciples to the specilic cases. aNo
bv a critical c>\aiiiiuat iiui of othci' possible causes, we may decide to
what extent dilVereiitial uplift is rcsponsibh'. and whether in some
eases it may noi be cut ircdy subsei'v ieul to oi her causes.
TIk iirijitf ilitYi n iil'ml insdlnlinii. — ,M\ nook and ,Missiim cii'idvs atVord
[lerhaps the best exampli's of unsyin metrical valloys. with their -teep
noftlicrii walls, as described abov<'. Here by tlie alternation of freez-
iiii;- and melting; icmperatures. I he ro(dis arc ln'okeii down ami the
•J«i; (iK();,()t;v i»F Till: vumin (iDi.D i)i>ri;iir, Alaska.
I
i»
iiiali'i'iiil is riifMi>liiMl 111 1 li(> si ri'Miii I'di' lriiiis|Mir1;il inn. IT I hen- is mix-
'^[•i'ti\ (lilTcrci hciui'i'M t 111' .•niiipiiiil nl' licil ri'i-i'ivcd liy cil Ikt liaiili,
the (iiic sii Ciivofccj will 111' liiiiki'M iliiw II iiKPi-i' rapidly, 'riicii. IT t lie
sirt'ain is alrcadv (i\ ci'lnadcd. llu' uri'alcr siippl v rfoiii Ihc liiudily insn-
lali'd haiilv uill ii'siill in \\\i- 'Tiiwdiir.: of llii' si ream away IVdiii llial
siili'iil' llii' \alli'.\. ir. Iiiiw c>\ cr, IJH' si ream is a riiiii|)i'li'nl niic, Ihi'
iiialrrial sii|)|ilicil will \>r hnnic awa\ , tln' iiaiik nf Lrn'alcr iiisulat ion
will I'l'inain sli'i'|i. and I lie si icaiii will How close to il. 'riii' side of tjic
\allc\ icc-i'ix iiiL,' llic most heal IVmii llic sun will lie the norlli, so llial
tlic coiidil inn npon llic Iwocrc'cks naiiic<l is thai called for liyllic
I licorv ; \f\ il is prohaldi' I lial oilier causes lia\ e I n si ill more ad i\ e,
'I'liat ditVcreiil iai insoialion isofleii sniiord inale to ol her I'aclors in
prodnciiii: assiiiniel ry is pro\ cil liy I he fad that many ai-l ively ciill inn'
streams, of w liicli l''ranklin ( in Icli and Napoleon ( reck, on {•'orlymile,
and Harrison and Kaiile. (ni liindi (reek, aie e\ample>. have their
steepest sides t'aci lit; I lie iiorl 11. Jiisl 1 he opposite to wlial llie theory
demands.
'I'hi nrii dl' Il ri'i si riiil rntiitinu. — .Another possible cause is ihai of
terrestrial rotation. In Is.V.i Kernd I'ormiilalcd the law that all hori-
/.oniallx' mo\ 'n,!^' liodiesin the northern liemi sphere are, I )y the rot a I ion
ol' ll art 1 1 iip<ni its a\is. delleded lo I he riyhl . At first applied lo I he
w inds. il has been e\ I end eel to ol her nio\ in;: lioi lies, sindi as sl reams ol'
water, ami made lo aeeminl for irveiriilaril ies in the wm'k of ri\ers,
where I hey seem lo he |n'esse(| a,i;ainsl liieir rin'hl banks. Ilspi-aeti-
cabiliiy td'applical ion has been discussed frcipiently, notal>ly b>' (i. \\.
(iilbi'it.' '{"he latter came lo the coiiclnsion thai terrestrial rola'on
is often a snilicieni cause for stream asymnieiry, and in a parlicniar
case — ( hi' .Mississippi -lie calcnialed t hat the select ivc Icndciicy was '.i
per ccni ureal er toward the riy:lit tliaii toward thelefi bank: bill he
also proM'd thai only under peculiarly faxorabie conilit ions could llic
cause 1 IVicienl. ■■.Vslrcaiii which rapidly corrades t lie but toni of
its channel does not notably corrade its bank, and in such case the
I'lTed of roiation should not be disio\ erable." The condilions of
rapid \i'rlical corrasion here described apply lo a nia.iority of the
streams I '' .Uaska. thai pari of the ^■||kon lyinu in the V'lats beinu
almost the only water course in which vertical corrasion is subordi-
nate to lateral; conscipicnt ly we shmild expcci icircstrial roiation
nol lo bee\erywlicre of primary impoilance. If il were the priiici-
|ial cause, wewiiiild alsocApcd similar results in regions similarly'
sitiialed. but il will be reniembei ed that, while the einin iimelils of
.Mission and .Mynook creeks are alike ami I heir \ alleys iiiisy innid rical.
in the (Uic case. ^Mission ( 'reck. I he irrealer erosion has been upon t he
norl hern or Icl'l bank in opposilion to I he ilelled l\'e force prodilci'il
by rotation. .Mso no general asymmetry was observed in the north
and siuilli How in.n' streams, althouuli by I'errers law all sircamsin the
same lat i tilde should siifVi •• equal delledion toward the riuhl bank.
Am, .luiiK S.M..:;,1 -..ri,.-. V..1 .X.XVII. 1^>I. r I.;;,
S3 '
I ■».
men. I l.'KCKNT \VAU1'1N(;S A> MHiWN \:\ DW MNAdl".. 2^1
Till I Ij'i rl III' i/i nil 11/ 11- si mil II ri . — Since ^l I'imhi^ :ni' iin^l:ilili' licidic-.
I li ■} ail' iitl'cflcil iiliil lli('irali,t;iiiiic'iil i-. iimiliinMl ami nil en alliii'ii li,\'
I iic iicoldi^ical siruci iiri" (if till' riicl<>. iiiid w liii-li I lii-v aici'diia'liuu: I lii'ir
lic'ils. SoMii' ol' llicsc iiKiilitical iiiii> all' liiral. >iirli a^. Inr i'\ani|ili'.
tile ilaiiis rrciiiii'iills I'liuml iipnii l^'urt \ iiiilf (rci'lv. ulini' a |iaiiii'ii-
larly resist a nl la> er enisses 1 lie heil ul" tlie >l ream : iillier>. iIih' i<> i he
atlilllile III' tile I'lieks. ale IlliU'e l'\lellN!\i' in ihrir elia rael el'. Ill ra^e
t he roeks are hori/.iiiital. ami there are iiii III her ili-.l Milling iiilliii'iii'i'>.
1 he iiiir.ii'e of a yiiiinu' si ream will lie eiil Nerlieallv. lull wit li a ili|i I he
(low ii-eiill iliiz ri'Mihes ilsi'ir iiilii Iwii eiiiii|i.im'ii!s ihr i me \ eil ira I.
ami I he iitlier almii;' liiie> (if w i akiiess nlVei'eil in i'iii>iiiii liy [ilaiie^ nf
schisliisily 111- si ral i Ileal inn. I'Ih' heil nl' . n' rrcrk, 1 llerel'nre. ilni's
nut priieeeil ilireet ly iliiwnwanl. lilll llli.;iat<'s in the ilireet Ion nl I he
ill) , anil the hank is eiil mure xiynrniisly nii that side, jirniliieiiiu' a
(iiie-siileil \ alley. I' he aimiiinl nl' a ^y mm el ry i|e|ieiiils iipnii i In- allele
nf lheili|i. W'il h hiiri/.iiiil.iiily il is n; at an am:le n|' |."i i hr ili'l'nrm-
in:^' lemleiiey is urealest. ;,;iailually ileereasiiiL; until, when the rm-ks
are xei'tieal. il is apiin i'. Ilnekskin. I'rankliii (iiileli. ami \a|inli'nn
ereeks are exainples III' st reams wliieli llnw ill si like \ alle\ >. ami in
all III' t hese t he ili|i is ral her sleep tnw an! the r.iiiltli. 'I'lie > alh \ ill
oaeli ease is unsynimet rieal. with the slee|iesl siile at thesniilh. ai'nl
t his wiinhl seem tn lia\e lieeii eaiiseil liy a niiiirai inn ilnwii the ilip,
allhnil.uli, as w ill lie seen later, ntlii-; inlhieiiees may alsn enter. In
.Missiiin anil llniiler ereeks the I'aels are ilillereiit. in eaeh the linl-
niek has lieell I'lilileil Siithat, as nl'len as lint, the eieeks ern>s the
strike and dip; the asymmetry nl' the xalleys. iherernre. is perfeetly
independent nl' the ili]i. the stee])(>r hank heinu' always iipnu tin: iinri li
lliroMjili all the \ ar.\ intr dips and st rikes.
'i'lie rneks of Hunter and Missimi ereeks lia\e mil mily heeii I'nlded
hut are ai.sn faulted npini a small scale, which snt;i;'ests the idea that
ma.jnr I'anlts lakini:' east and wesi enurses are respniisihle I'nr the
enlirse nl' tile ereeks. and that the siiUlll-raeinil' wall ahn\e deserilied
is a raiilt eseai'pmellt. ilnwexer. there i> nn cNidenee In sustain this
Mtpposit ion.
Till I ll'i rl III' liliimi. Il is seen. then, thai the .general causes nf
terrestrial rnlalinii. insnlal Imi. and ,neii|nL;iral slriictnre. while appli-
eahle in special cases, are insullicient to e.xplain all the nhservi'd
plienoinena of one-sided ness. We are iihlii;i'i|, t here lore, to seek some
oilier e.xplanalioii. and the only remaiiiiiii;' one is thai nl' an iiiiei|ual
nplil'l, as sii.t;!,'esteil at the heiiinniii.L;'. \\\ il all phenoniena not
explained under Ihe olher olles may he accounted I'll!'.
in the Mission and .Myiiook systems of drainage, particularly, there
is a retardation of tlie sonlliw ard-lhiw iiii; waters and an acceleration
of 1 1 II ISC llowiii^i' north, whieli is seen not only in the hraiiches. eau-in.y:
ineipialitiesof drain-iiic development, hut in all the meanders, 'i'iiis.
il M IS. could have heeii iirodii 1 only liy a tilt of the surface silii-
.jected to erosion, in this case toward 1 he norlli.
T
'JHS (iKOl.ddV or TIIK YUKON COI.D DlsTliHT. ALASKA.
n:,
Mi.
fWi
111
'I'liv ;;icali'i;iiii\ il \ III' I lie ih ii'l liu ;i l(l-llci" ilii;' si riMiiiN ciT I lif illicli
Cii'i'k ilislric'l iiN (•(iiii|>iii'i'il \\i\\\ iIkim' sil iimIimI til llii' .sdiil li (iT ihc
iiiaiii ili\ iilc, lllc Ulisyiiiiiirll'i<-al Niillcvs ill llic lii(illlli> nf riin-M|iiiii',
Millci'. iiiiil MaNliiiliui ciTcks. MS also llic rcclaiiLiiilar arraiiiiciiiiMii dI'
t lie ili'aiiiaL;c ill \\[r I'lii'cli ( ri'i l< Hals, iiiilicali' a I ill li)\vai'(l I he ikhi li
ill llii-» |iarl iciilai' ari'a. 'I'lii' i > ai-raiii^ciiiciil of llic ilrailiau'i' in a
lilted ilislrici is, ill a way. an imlcx nf tin' ilirci'l Ion and axis ul' lili.
Fnr cxamiilf. in the cases just cited I lie t inn k st reams are si laiulileii-
inj;tlieir eniiises ill a general east-west direeiion. slidwiny thai llie
axis (if I he lilt is also I'asi and "est, while I he aecclerat ion ol si n^aius
shows the slo|>e of the tilled siii'laee to be toward till' nor<li. The
si reams llowiii;r into llireli Creek to 111" south of the moiiiitaiiis lia\e
been cited alio\ e as showing' I he in II Mel ice w hi el I li-euro^ical st riicl lire
exerts upon I he drainaii'e. Late warpiiij,^ is disrc.tranlcd liere or is
altseiil. I'or we lia\'e seen that iipoii Myiiook and Mission <'rceks a lill
opposed to the dip of the roeks. althoiiiili prohalilv aimiunt iiii;' oiilv to
a fraction of a foot in the mile, was still more important than I he
latter in caiisiinr as\ iiimcl ry.
We should expect then, if there were a tilt ill o|)|iositioli to the di|i
of I he rocks iii)oii Kaiile (reek, that it would lidvi'iii the ali;;nmeiil :
on ihe colli rary. however, I h.- dip u'ov erns, ( )n Harrison (reek ilie
stei'per side is at thesoiitli: at Kau'le ( reek it is at the iiorlhwesi,
and miiiratioii down the dip is ol)ser\('(l. especially well markeil, jii>.i
alioM' Ihe luoiith of the latter. 'I'hesi' two creeks, allhoii^h near
tou-eiliiM-. yd iniurale in op|iosite directions, foUowiiiu' in this ehaiiLie
a local \arialioii in I he alt il inle of Ihe roeks. Here. then, there' can
lie no till toward the mirth: further, I here can lie iioiie to I he soiii h.
else Kairle Creek would lia\e been crowded to the soiilh side of its
valley. Harrison and Kaiile creeks are therefore located in a region
of no I ill . proliably aloiiLt an axis away from whicli I he surface ha^ noi
only been tilled towitrd the north but also toward the south, in the
direci ion of 1 he 'ranaiia. forniint; a broad aiii leiiiie. ( )n I he l'"oriyiiiile
Creek di'aiiia,i;e. l-'rankliii (Juleli and Napoh'on Creek liavi' unsymmel-
rical salli'ys in which in each ease thi' stream has iiiiuraled lo the
south side. 'I'liese lia\e also been iii\ en as cxaillples of I he i;'o\ cril-
iiijr inllucnce of struct lire. Il is probable I hat no tilt hasoeeiirred in
opposi.ioii to till' siruclure. and there arc reasons to b('lie\ e that the
|)ceuliar oiic-siclecl \alleys are produced by the two causes aclini:
Jointly ill the same direeiion. .lust aboM' l-'raiikliii (iiilcli. on the
main creek, the canyon walls fall ba(d< and tic \ alley spreads out
into a Hood plain a mile and a half wide and extcndiiiu' some t wn or
three miles u]) the creek. .Miove this Ihe canyon isaj;ain rcsiimecl.
The cause of the bottom land at this point is evidently a poiidin:;' of
the water by a dam; but no local dain is now to lie seen. This is the
result we should have in the evi'iit of a tilt of the surface toward
llie south, Ihe tiltini:' opjiosed to the iri'adient of tin- stream not beiiifj
oc.oi.iMcii.] RK( ENI' WARI'IN'fiS AS SHOWN 1;Y IH.'AIN \(ii:.
'J8i)
groat ('ii(>iifj;li to rcxcrsc llic ili'iiinnL'i'. luK snilii'ifiii in i-aiiM- a ixnul-
ing lit' tlic watff alioNctlu' iMiint wlicic tlic axis itusms il rci'k.
Uiisyniiiiclrical xallcys «itli llii' sIccih'I' si(l(> at tlii' soiiili wcw also
olisorviMl iipoii (Jlacicr and .AJilliT creeks, w lien- ;liey are iiiclnjieiiileiit,
of tlie jre(ilo;,'ieal sUiicliire am! were jirolialily prcMlueid liy iiiiec|iial
uplift.
SIM.MAUV.
I!y ail exaiiiiiiatiou of tlie Yukoii I{i\er ami Inriyiaile, .Missinn,
Uiicli, and ^Myiuiok creeks it appears llial diiriiii; liie elcvalicm <<( tlio
present unc()iiii)lete<l p'o^rrapldc cycle liroad folds were itrudiiced.
Ill almost all of llie L;dlil-])ro(|uciii;r .irnlclies tlie plienoiiiina arethoso
of a iiioiioclinal tilt toward t li(> iiortli, hut at cerlaiii oilier poinis, as
upon tile South l''oik of {•'orlyiiiile, the till appears to he loward llie
soiltli. the strilcluii' hein^f jinticliiial and, according tc llie ariaii;:e-
nu'iit of tlie drain ;,'<■, alon;;- northeaslerly axes. While ilie location
of the axes can not ho aci'iirately di^teriiiincd. one of these jtrohahly
very nearly coincides with tlio crest of the ( rookicl ( reek-riirdi ( 'reek
divldo and has a direction \. 7iP M., the headwaleis of liiich (reek
proiier heiii<j; located in the rcirioii of no till.
In the I'"orlymile ai'i'a an anticlinal axis passes in the Nieinityof
Franklin Giileh, crosses iiorlh of the head of ^^■alkel■ I'ork and into
British territory to the north of the pild-prodiiciiiy; creeks, .Miller ami
(ilacier. This a.xisof recent anticlinal warping- very nearly eoinciiles
with the ancient anticlinal a.xis.
is GEOL, I'T 3 19
m
/;'•
•i!
1^
( II A I'T I', I! V .
\.\i.[ \i;i.\: ^\\:l^.l.> in >t»i,ii> imm ks.
'riiniunli'iiil llii- disliict wliicli li.i> I PI '('11 (li'scrilicil niiil iiiii|)|ici| ilicro
iiff in nmiii'iDiiN pl.iccs \ alii.ilili' iiirlals, i ■.•<[)( ''iallyi,^!)!! I. Willi ics|iccl
|i> 1 liiMi'dccMrrciicr llicsc iiM-liils iiiiiN' Ipc ili\ iilcd in Id I wocliicf ciasscs- -
lii>t, IIkim' uliicli all' fiiuiMl ill llic solid ruck, lia\ iiiy I licrc hcci ii-
LMMil lad'd liy (•licinical auoiicics, and, sccuiid, Ihosc which iir in rucks
made lip of dclriliis dcriscd IVdiii llic uhh'r solid rucks, I'runi which
dclriius llic licaxy iiidals. such as i;ul<l, ha\c been incchanically scp-
arat(Ml. 'I'hc (irsi class may lie callc(| lie 1-ruck depu>.ils, and lliesec-
uQtl, jilaccr ilepusiis. riacer dcpusits arc nsnally i'uiiiid in luusely
cunsulidaled river ;fia\els. In Alaska Ihc irravcls liil hcrlo wurked
have been fui'iiicd in cumparalively receni limes, lint in ulher rc;;iuiis.
such as I'liitish ( ulnndiia, (alironiia, and Aiislialia. I hey are ul'ieii n{
'I'crliary a,i,'e and sliiiiitly cunsulidaled; and in sunic places il may
happen that slill mure ancicnl uravels, w lielhcr funned in riVers ur
nil he.iches, lia\e liceii eiiliiely cunsulidaled su as lu runii a liar(l con-
jilumci'ale, while Ihey slill cunlain Ihc iruld uriirinally (ihlainc(| liy
mechanical I'unci'iil ralimi. All lhcscuhli;r depusils, huwever. cunie
under Ihc head (if placers.
In Alaska llic precious mclals in Ihc uldci' sulid rocks, or Ihc licd-
ruck depusils, uccur, su far as iiutc(l, in l\\(i chief ways — lirsl, in
(|iiarl/. M'ins; sci'ond, in mineralized slicar zones. Tt may be iiolcd
in passing liial in Alaska, ami lu a h'ss extent in oilier mining cunii-
Irics, the term "(piartz miiiiii;;" is err<iiK'uusly used liy the miners to
inclndc all bed-rock miniii;,'as opp<ise(l lo placer miiiiiijj;. 'I'his, how-
ever, is ncilherin accord with the facts nor with Ihc common iisa^e
of miners in bcttcr-dcvelopeil cuimti'ics, since (piartz is a delinito
mineral, and the term "((uartz minin;,'" refers sinqily to llio wurklng
of veins uf (|iiarl/ which carry i;uld.
QUARTZ VEINS.
Oi-ciirn iiri . — \'eins t^f i|uartz ai'c found in f;rea1 abnn<laiice all
tlii'unjih the schistiisc rucks uf the I''urtymile and tix^ llircli ('reck
series. They are alsu fuiind uccasiunally, but nut very freciiicntly, in
the fnndainental ji:ranilc, and ai'c cummun but not very nuniei'ous in
Ihc rucks uf the Hamjiarl series. In furmatiuns which are of yuuni:er
aife than the Mampari series, (jiiartz xcins ha\e locally de\(dujieil as
2SH)
■■'ii
■I'lKKl
</r AIM/ \ riN^
111
a (•iiri>.c<|iii'i]<
(■ IJI >l
line -^lirci ill ciilnlil idll^ 111' IllllTHl idh ; 1 lilt .O U ii l(
spi'i'Mil Mini cliMrMi'ii'i'l^i li' |ilii'iiiitMi'iia llii'V may lir >ai<l in lie cuiiruK'il
III llii' l{aiii|iai't ami oIiIim' nicks, ami In In' liy I'ar iinol i-iiiiN|iii'ii<iiiN|y
tli'V I'liiiicil III I lir l''ciil \ III ill' ami I III' liiii'li ( ii'i'k I U>.
It.
fismiis III
liiiiiil III iii/i . Mii-i !•{' I 111' i|iiarl
/ \ lill- ill lllr I'lirl \ -
ir.ilc and liircli Creek i ks are iiarni" ami ieiii|H'i-.i-iiiii \\,,-.\ uf
tliem are parallel uiili ihe •.i'liisiii>ii \ . Inn xmic cin aem^v n. ,iiii|
lliese usually slmu llial llnv lia\e lakeii pari in llie iiiii\ I'lnciiis
of llie iiieliisini;' nieks. 'rim-e uliieli are parallel uilii lie- ■.■•lii^ln^iiy
are iil'len slireil apart liy iiiiilinii aloiii;- llie .slu-arilii;' planer, nr lia\e
been I'oldeil ami eiiiiliii'led (see I
in'. --(; olliers elll aei'iis
llie -I'll
tiisily I'm- a lil I le ili--laiiee ami I lien lei iiiinaie alniipl l,\ . a> if I'anlied
liy imiM'iiienl almii;' llie M'liisiii-.ii \ planes, |i is e\ ideiil lliii ilie
1 ks Were iii'iii-inally iiilerseeied liy many \ eins. sniiie nf \'liieli ran
]iarallel in I lie si ralilieai imi and uilieis across ii. 'I'
lese 'ins were
pidlialily iiiice imire emil iiimnis iliaii imu. Iml lliey liaM' lieeii sn
lii'dken. ranlled. slieared. and separaled lliai llii'\ are imw iisiially
ski't.li .il' c.piitoi't.'.l iin.l ■,lii',.il.l,.,l iiMii
■t/ v.'iit-i ill l"'>l'l\lnil.' --illNr.
ini
iipersisleiil . N'eiiis nf I liis class a re luiiml sparini;l.\ in lln- iimler-
lyiiii; .H'ranile ami mil al all in tlie iiverl\ iny- Itamparl series.
i;
■sides Ihei
sheared \('ins are orieii nlliers uliicll elll acriiss III
.seliistosity, Jninliiii;-. and ul her st rnci iires resiill inn- lliniimli disiiirli-
aiiee witlioiil any break, sliuwiiiii' llial llie\ are laler t liaii all imi\e-
inciils ill Ilie i'(«d<, and tiieret'di-e disliiiclly yuiiiiuer than llie veins
just dcscril led. On l'"()rtyinile (reek I liese \ eiiis cut aemss i lie ele.-n -
ajfo and llie older qiiarlz \-eins and liraneli so i lial I'l-oni a lifi le dis-
lance tliey lia\e llie appearance of dikes. (See Hi;-, l'.!. ji. -y.'-J. I 'I'liey
oi'leiieonlain a little I'eldspar. and sonielimes. hy increase in aimninl of
this mineral, iiass into a \ariety of line pei;inal iie: this in turn seems
lo lie I ransit ionai into a coarse aplii
pllte. ulllcll
is \ er\ aliiindaiil .
In the Uii'cli Creek district, also, persistent, wide i|iiart;' veins an-
found, alt lioii.ii'ti in sinaller niinilier lliaii I lie schistose veins, aiitl in
tills di.sl rid also they often coniaiii feldspar, and are associaleil "iih
ai)li1(\
In the rocks of the liampart series lliere are fi'cipieiil ly ipiartz veins
formed aloiiii' shear /.ones. These i ks were formed practicallv siili-
seiiueiit to all re,iiional seliistosily, but llii'y have been .jointed t hroiinh-
f
2:'2 (iKOI.oOY (>!■' TIIK YLKOX (iOl.D DISTKICT, ALASKA.
(Mil, iiml till' IimmI iiilcnsilN' III' joiiil iiii,' Ii;i -i I'l-tMiiiciil ly IhimIii 1 /.(iiii>s
of sliitlil iniivcmi'iit ni' shc-iiiiiij;, aii<l .•iluiitf these /.(iiii's (niarl/, M'iiis
liiive ruiineil in llie o|)eii eiat ks. 'I'liese \eiiis ii! > iievei' ,slieare(l, ami
are lliei'el'(ir(^ Mihseijiieiil Id all iiiiporlant iiKiveiiieiil in tlie rocks.
Ml hill it CI III li' Ills iif iilili r riiiis. — III llie ohler sc-liisliis(> veins pyi'ile
is \ cry ciiiimioii; $;alenii is ri'e(|iieiil, and ijold ol'l en occurs. Tn tlie
l'"(irlyniile (lisl I'ie!, L mile alioNe llio nitiiitli iif |)a\ is ( 'i-eek, is a vein
called l.iiwry's ledu'e, wliicli is liMo 1:.' inches thick, and lies aliim^l
liori/.ciMlal ill the lied cif tlie ciecdi. This vein coiitaiiis free j;i)ld. In
a iii\ ilie or |)il|i of .Miller (reek, in the same district, a (|iiait;'. ledi^e
has iieeii t'omid which shows free fiold; and on the same creek is a
wi<le, irreuiilar (|iiai't/. xciii called JJoyd's ledne, ^^llicll conlaiiis
Vu; :.':! (.iiiiili/. li-M-'iiiu- v.'iii mi -i-liist, S.mlli Fork .if iMU-ty mil.' ( 'i-i'i'k
iraleiia in irremilar lilolches. A small s|ieciiiien of this i;alen:i assaxed
ity the Siirvev yielded nouoldand I. il ounces sihcr. .\l the head of
(«!a<Mer (reek free i,Mld is said to have liceii I'onnd in a <|nait/. vein
wliieli has Iteeii located by Mr. \ors<'. In l''r,iiikliii (inh'li is a wide
• liiart/ \ein near which coarse }j;old occurs In such jiosition as to indi-
ea((» its derixation I'roi,. !jie \eiii, althinifrh no free irold was actually
•-eeii in the oiilcro|i. < i the Yukon UMxcr, near the month of .Stewart,
j,'old-l)eariii,u' quartz \i ns are report ed.
Ill the Lower )'aiiiparls there are the same (|nar(/. \ eiiis as on ihe
upper river. .V pi 'of <|nart/ hroiiirhl in liy Indians froiii helwei'ii
the Hess and the 'rroiililesoiiie rivirs was vcllow apd caxcrnoiis in
'W
I .1
&
ii'
^I'l Kit. 1
i.irAUiz vriNs,
203
iippi'iii'.'iiu'c, hill '^nw ill I ln' .s|icM'iiii('ii (ihlaiui'il l)\ ihi- >ui\i'\ pailx
only 11 trace of t-tild. 'I'liis. however, u,i> liy nn iiiciii^ m lair saiu|ile.
On tlie 1 lead waters of I he Hess Ki\ er a w c'll-Uimu n pi ■ is peel m-, ( )|i\ er
('. MiUei', has driven a luniiel J.'i I'eel iiiio a (piarl/, \ri\ixr \vliich is
said to lie aiirireroiis. On 1 he riyiil -ha lid side of I he \' iiUoii, :;."i miles
lieiow Taiiaiia posi, a I iimiel has been driven I |o feci on a (piarl/ \ ein
in 1 he I'dreh Creek sehlsls. 'I'iie \ ciii, like so nian\ oi liers, lias liecn --o
piiielieil and faillled l>y niov eiiieiils in llie rocks Ihal il c'aii liardly
he followed any j;i'eal dislaiiee, and Ilwrefore iis iiiiiiiiit;- will always
he\ery niieertain. A laiidoiii sample of ihisxcin nhlaiiied hy llie
Survey parly. uaxc on assav o.ii.'i onnee i^old and o.:; (Hiimi' ^il\ cr In
the Ion.'
Ml tiillir riiiili Ills Iff iiiiiiiK/i r ri iii>:. The \ oiiiiiier I pia I'l z \ c'i IIS, w II ii'li
lia\e heeii iinail'eel("d hy iiioxemeiils in llie rock, also eonlaiii nielals.
[•'il'leeii miles soul liwesi of ( irele ( il \ , ( m ihelrail which passim I he
Kiuiil mile . aehi', lliere is a ipiarl/. \ein carrying iiindi free i;(ild. A
spec! lev ii ill 10 r poscssion from this \ ein is of 1 he lianl. w hile i|iiarl/.
whieli is mil ^-eiieral'y supposed loeoiil.jn iiold. Iiiil t his speeiineii is
in pJMi'es \ ei\ full of lill le I hreails and si ringers i if I lie precious iiielal;
il also ciiiilains a lil lie py rile and hemalile. 'I'lii- \ ein is said In he
III feel ide, and has heeii slaked hy a miner named Mel. I. ( >ii
llou'ein ny I )eadwiiod ( reidi ill I he same disi riel I here w as found under
I he !,;ra\ el> on Isaloirs elaiiii a wide \ein \i'i\\ rich in i;aleiia. .\ ran-
dom . ninple of lliis ohiained li,\ lis assayed I I ounces in silver and no
^'old. On (ireeiihorn ( Jilleii a fi'a,u:meiil of cpiarl/. picked up in the
jriavels was lull of cavities wiiich were appareiilly lefl hy llie di ii-
posit ion id' mel a llie sulphides. 'I'liis fra^inieiil showed mi mile specks
of free i;old, ami on assa,\ yielded i' 1 ounces of sih er lo I he I mi, I hiis
suu'iresliiif;' llial il is a lii,i;lil,\ wealliered speeiineii of llie saiiie\ariely
of ore v.liicli was found on llo^'em (reek. \\ llie lieaii i'f l'',aL;le and
(iold I >ilsl i; 11 Idles persisieiil and w ide ipiarl / \ eiiis ar ■ said lo e\isl,
the lineal llie head of (iold Ihisl (iiileli heiiiiiin places as much as
l.'iO feel \\ide, and eonsisi '. ^Mif cavernous, riisly i|iiarl/.. The saino
veins are found at llie head of Harrison (reek. On Harrison ( reek
a block of oiiarl/ rieli in uold was foiiiid in llie gravels on c'aim ',>\ on
Hie Norlh I'ork, ahiiiil llii (piarlers of a mile abuse ip lunclioil
wilh III" Soiilh iMirk. The block buinil is ronnhly s.piar ■ willi sharp
corners, and is aboul ."i inches Ion;:;. On one of lliela'.;e laces is ii
I hi II coal in,!;- of cr>slalline i|iiarl/., less Ihaii a i|iiarler of an inch I hick.
Iinbediled in I his ipiarl/. are ahnndanl heads nf ;;old. Hie larnesl oiie
of whidi measured I liree-siMeenl lis i f an inch in diaiiielcr; from
which si/.e llie fraf;meiils become smaller uiilil linally I hey are iiivisi-
hle 111 Hie naked eye, ,ilHioui;li a iiiai;nif> inu' uiass shows llieiii lo bo
])resenl ill considerable ipi.inl il ies. dissemiiialed lliriiiiL;h llie ipiarl/..
'J'he Ipiarl/ \ ein which carries Iliis -old peiielrales llic sdiisis nearly
I AH us-^ny- In Oi.' Siirv.v w. IT inii.l'' !■> I'i'.M i i;. Mum
.
f
I ' !
2111 (ii:()l.n(;Y or Till', YUKON (iol.I) DISTU'ICT. AI.ASKA.
at I'i^'lil Jiii.ulcs. til us slidwiiiu- 1 1 lilt it is ilistiiic!l\ younger in iiuc tli:iii
tlic lillliiiM'ous ii(iii|M'isisli'lil \cilis w liirii ;in' (lidci- tiiaii I lie il<'vlci|)-
niciit (if the cliicl' scliisidsity.
( )n ATiicricMii ('r('cl<. near tlic licad. UDJd-liciii-iiiL;- (|iiai-l/ xcins lia\ c
bci'ii icmid. On i.iltic MyiKink (reck llic iiioviMnclil alony liic siicai-
zoni's lias asiiinaliy resulted in u|ieii lissiires wliieli liaxe Imciiiiic
filled Willi white, eiystalliiK' <niai-l/. Ncins. These often slniw (■..nili
struct lire, and si tiiiet lines lia\ " a vacant space left in the center of I lie
Vein. Ilie walls of which are liiieil with crystals. One \eiii seen was
about li feet wide. This lediie has i^eeii slaki'd l>y a iiiiuer iiaiii('<|
Sinclair, and samples of it yiidd on pauniui;- a small c|nanl ity of liiu'
golil. Similar \eins occur on ilunler ('rcid<, bill are not known to bi'
aurib'idus.
Mii-riisriijiii' (irciirr( iirf (}f ijiild. ~\\\ only <iiie thill section was uuld
found under the iiiicr iscopc: this was from I he iniart/. \ ciii w liich has
been iiiciilioncil as oecurrinn' nortliwi'st of Kiirhlniile caclie in I he
IJirch (leek <list rict. In this spiM'iiiieii some of the (|iiarlz appears
dark ami dirty from the abundance of inclusions. This ilark i|Uail/.
has been hreccialcil and iierfect l>' cemented aiiain by a (|uarl/. which
colli a ins few inclusions, and so appcsirs clean. Thrini^ih both \ arieiics
ofipiait/. run crai'ks. and at the intf r.section of two of these is an
irrejiular bunch of y<>llow trold, associateii witii aiiolher oi)a<|ue min-
eral, which iiia\' lie liciiiatile. The sliuhl (don;;:it ion of tlie,ydld aloiiij
the crai'ks in two directions siinjicsls thai these lia\i' induced iis
deposition and thai of the associaled iron mineral. The cracks are
stained by limouile. showiiii;' tliil t hey are si ill callable of act inii' as
channels for soliil ions.
nl
mm
I!
!i
MINERALIZED SHEAR ZONKS.
The Veins of pure white crystalline i|uart/. which have lieeii
described ofien shou by I heir co!'ib si riicl tire, or even by I he lea\ ins;
of residual cavities, t lial they are hlliuns of preexisi iiiy- open li satires,
nnil it is iirobable t hat this is usually the cise. In ot her iiist.iiiccs,
]lowe\er. silica and melallic sulphides lia\e been i.itroduced into the
1 k ilia i|uile ilill'erent way. Where rocks liase been profoundly
sheaied. so that wliilc no open lissiire is presented the whole crushed
I'lick oll'er-. a ready (•h.iiiiiel for percolat iiiy waters, both the she.-ired
rock and t!ie more massive portion iniiiiediau ly adjoinin;;' are usually
fonnd fnrllier altered by chemical means. This is especially 1 he case
wln'fe the I'ocks ale on the whole massive and are milv locjilly
sheaied, so thai there arise delinite shear /ones, almi^' which llie
Water circnl;it ion is ii ssarii.v concentrated. l'"or this reason the
slicar /.ones are most conspicuously altered in the {{.imparl series
rocks, since in the older lormalioiis the shearini;' is more general, and
in the yoitimer ones il has not been nearly so yfeal. The chemie.il
ClTccIs alolii;- these shear /ones are liol ice;|lile in llle tield ehiellv bv
SI'IMllv.)
MIXER ALIZIMi SlIKAK /.(iNKS.
295
ill) iiiiliiral iiiii wliicli iiriscs rnim ilic ilc'iinsii inn ni' -^iliiM. iiinl liy ;i
staiiiinu' i-i'sulliiii;' I'l'inii tln' loMaiimi <il' ilic iiii'iallic- --uliiliiili-- wliicli
lia\i' lii'i'ii loniic'l. It -iiiiicl iiiii's lia|p|M'ii-~ ihai alnii:;- tlicM> >licai'
/(iiics while i|iiarl/. mmiis rm-iii. cvidiiilly uli'-ic aciuai li->in'c> lia\ c
oxislcil, Inr Ilii'v alv.axs cdiitrasl >Ir(iiii:ly willi the Maik, iiii|inri'
JasiHTnid (ir I'hi'i-I wliii'li iiri--c'-- rinm ilic >ilicilical inn nf the (■(niiiliy
I'ook.
nccri.'KKNcKs.
Aliovc I''i)flyinllc Cri'i'U. in t In' >riiist<isi' i-iicl<-i (i|i|Misiic l In' nmiil li
of llir Klein like Kiver. a llll nrl has lieell dlis eli i 111 (I a \\ ide lind\ ef
ore. Tliis tiiiiiiel was iml vi-ited. I)nl il is <'lainn'il llial ll re has
l)eeii assayed ami i-niis-s."]| '.o I he Inn >^l^in sil\i'rainl s;;!', in LTnid.
Mr. McCoiinell' miles laal lieluceii l-'di-lyinile (reek and l'''i't.
K(>liaiiee eoppei' pyriles ill small iiiiaiil il ies 'iirs al sexcral peiiiis,
nol- ill llie xeiiis bill as Miipri'irnaliiiMs of Ihe sehist ilsell'.
( )n l''(irlyinile (recdc. J nr '■'> miles almxe I he nmiil h, are shales, sand
stones, and liineslones wliieli liave lieen liieallv sheared and inipreL:'-
lialed wilh slll|)hides. alllioliuh on Ihe nnli-mps nmsl nf lln' sulphidi'S
haM' lieen leaehed out, making; the rocks rnsly and erumhly. On
('(ine Hill, direel ly opposile Ihe monlh of Clin Ion ( i k. Ihe i k is a
limestone, soinewhal altered, 'rhmniili this .'lilered mek run- .1 /one
Ji«i oi' :!i"i feel wide. \vhi<'h is eonspiennus al a "lislanee on ai-iiiniil nf
a dark-red slain. 'I'ln' rock is found mi fresh break- im be >laiiU'd
screen, and tn be made up lari;cl\- (if line eryslalli '■■. with
considerable (piart/,. 'rnis /nne enl- serlieally 1 . . il.e less
altered rock in a mul Invest -snnl heasi di reel inn., and appeal's to he
eontiiimnis and nnfaiilted. bill'iwini;' a -el nf vei-ii.'al jo'nt-. I mhi-
thi' miernseiipe the allel'ed rnek i- seen In be still essentiallx a lill"-
jfri'.ined. erystalline dolmnile. sniiiel iines eonlainiiii:' eh lienmlile;
then' is alsn a litlh' cinarl/ in very line iiariieles. as if sei-mnlary and
in process of i'epla<'iirr H arbonale. Small mas-e-Mif a dark-bi-own
nietallie miiiei'al, snrrnnnde.l by a sli-hl slain ><i -reeii. an' scattered
throimh Ihe rock. ( ■henii<'al examinal inn by Dr. \V . !■'. Ilillebrand
shows that Ihe inali'ix i- a dnlnmile carryini: cnnsiderable irnn and
nickel earimnales; also some mineral nf antimony ami arsenic In s-iall
. (]nanliiies ami solnble in h\di hloric acid. The iirecn portions are
insoluble in acid, and therebire pi'obabl> a silicate ni- ,|nail/. and Ihe
slain is some compoun;! of chromium, nndonbledly dei'i\ eil frnm Ihe
oxidation of chromiti', whii'h is the iiieiallic mineral aci-ompanyiiie-
the u'rccii slain.
Asampleef thi-altci'cd rock was assa\ed bylheSurve> and slinwed
jn> ji''il'' "I' silver. It is r'laimi'd, Imuevcr. that ntlicr -am|ilcs ha\e
shown Ihe lire tn be a Inw uraile 1:1 hi ore, capable of beiny: worked
under favorabi idiiioiis. .\cconlini;' lo .Mr. Oijilvie,' of Ihe Cana-
I .\r,ii. li.'i.l (l.'"l. Niii Mi'^i, Sui'vi'v 1 iiim.lu. V'.l. IV, IwM-sii, p. :ii)t).
■•^ii
t
2116
Gr.oi,o(iv or the yuko.v gold district, Alaska.
:t
i.'
Ui
.'.(,
<liaii SiiTNcy, a .small Imlc (if arjjciilirei'ous f^alciia cnjsscs I^'oiM yiiiilo
C'rcfk a cDiiph' of miles abovo its uioutli. A speciincii of tills,
analyzed by Mv. Hoirinaiiii, i>C tlie ( aiiadian Survey, yielded o\ci'.'!S
ounces of siivei' to the ton. Ti'aees of li'old and siU'er were found in a
s|)eeiiMen of alleie<l sandstone from above Cone Hill, on l'"oi'tynule
(reek. In an assay made for the writer by. Mr. |{. II. ( )l1ieer, of Salt
Lake Cily.
<>n .\merlean (reek were oliservcd nunieious shear zones, aloni^
Avhieli I he roek was sillcilied and eonlalned, besides ealeite t'opperand
iron ])yi'ito. In the jrravels in the bottom of the creek is found mag-
iielitein good-sized, walerworn pebbles or in small, pei'fect ei'ystals,
aTid also much barlte. I'"rom the association with fragm(-nls from the
ad.iacent rocks It is probable that these nnniMals are likewise derived
from shear-zone deiiosits; and it Is <|ulte likely that the gold itself,
which occurs 111 coarse fra.u'mctils in the .u:ra\els. ma.\' ha\<' the same
origin; therefore, bed-rock di'])osits of considerable richness maybe
found on American (reidi and \icinily.
All through the Lower Ramparts of the Viikon the rocks of (he l{am-
jiart series are much .jointed and are locally sheared. These shear
zones are sometimes imprei;iialed with Milphides, and often narrow
(piaitz veins liasc ''lU'iiieil conformable wlili the shearing. The \('iiis
are sometimes slightly cavernous and ri ; ■,., showing the decomposi-
1 1on of l)ree.\ist Ing su.'jhides. .Mioiit l'.T ii:i|es below I''ort Ilaiiiliii a
sample was taken from a sheared zone in a dark aplianitic rock.
Along this zone the I'oek was decomposed and yellow, 'j'his saniiile,
assayed by .Mr. U. H. Ollieer, of Salt Lake City, gave (l.ns ounce gold
iind a trace of silver. I'nder the microscope the rock is seen to be
a InlV, consisting of a line-grained groundmass in which are .s<'attei'ed
rounded <ii' angular fragments of ipiartz anil feldspar. The ground-
mass is Inudy mierocrystalline, often spheriilltic. The general altera-
tion of the rock is shown in th(> in'oduetion of kaolin, chlorite, epldotc,
and carbonates disseminated throughout. The elTeci -- of pressiirearo
shown by a strong set- of ii'regular but generally jiaiallel fractures.
Along those are occasional veiiilets of cry|)tocrystalliiie silica, dark-
brown oeherous linionite or blood-red translucent hematite, a milky-
white, seinioi)a"|U(> mineral which is ])robably siderite, and a \-ellow-
greiMi mineral of eousiderable single refraction which was not deler-,
mined.
Ill the l{am|)art rocks on ^f.vnook Creek tlie same |ilieiiomena were
noted. The alteration of the r()(d<s is shown by sllieilication and t'le
deposition of suljihides. This alteration has taken pUiee along shear
zones, and also in some eases along the stratification. Sometimes it is
irregular, following now one set of joints and now another, and now
the stratilieation ])lanes. The jiroeess seems to lie essentiall.v one of
replacement along zones of easy ])enet ration, and the minerali/ed
portions of the rock do not seem to have any constant direction. The
\^
MIXKUAI,I/,KI) SIIKAU /ONKS.
2!) 7
joint plant's llu... "hcsilu imt scciii to Ii.im' any niiiiUcdly id'cdoiiii-
nalit ti'Pliil, iiml llicic is lilllc cs idcini' cif any iin|Miil,iiiI iiinxcincnt
jilonj; any of llii'iii. Tin' apiicaraiii'i' is as if a massive vurk iiail '.ict'ii
.subjected to scxcre sirain. lull iiad been lifiidy lielil airaiiisl slitipini;;
tlms the most Jcii tiled ami hi-oken ])iiiii<iiis ol' ilie rdck ari' nf In-eirular
.sliai/e. In i)laees, lioweM'r. tlii're lias heeii slipiiiiii; and the pindiie-
tion (if yeniiiiie slu'ar zunes. (»ii Miller (Jidi'li, iiall' a mile almvo
Utile Alyiiook ('re(di, are many iil' these /.niies, iiiipiejiiiali'd with
siil|)iiides: aii<l near the moiilh ol' ihe ,^'iileli. (iii the main Myniiok
Ci'eek. is a liody <p1' allefed fnek alioitt 17 feel wide in all. which fol-
lows now the jiiiiit planes ami tio'vthe st fat ilieal ion. This oiileiop
is yellow wilh ifoti, hit I often has a lifecn slain, which was detefmiiied
l)y l)f. \V. !•'. liillchf.-ind to he a niixl iii-e of calcite and co]ipet' silicate.
I'lidef Ihe niicfoscope the wall focks of this iiiiprei;iiatcd liody;if«!
seen to be a hard, aphanitic. iifeeii stale, while the Ncin itself is a
Cilleai'eous sandstone conlainini;' occasional broken bits of mica, in
tiie interstiees between the (|uarly. lii'aiiis is abitndanl jiyrite. idiielly
t'<>l»per })yrite. The inti'fsl ices between the (plariz iriaitis appear
originally to liave been lille<l wiili calcite. in which tin' p,\rite has
been deliosited. Small el it in] is of siilerilc occiif. and the utceti cojjper
stain suri'oiinds th<' pyiite ami ffom here has spread Ihroiiirhoni the
rock, 'i'liis locality has 1 it I'laimed by ( >. ('. .Miller. .*v sample
a.ssayeil for theSiirvi'y by I'rof. ('. I-'.. Mitnroe jiave uold ii.dn. silver ii.i"t;
one assiiyed by .Mr. i{. 11. OtVicer, for ihe writer, iravt' a Itace of u'ohl,
and silver o.l' ounce to the ion. It is claimed, however, that |ifevious
samples liave siiown considerable (luantities of the precious metals,
one iissay lieinn said to inivo shown xl".ii'i 1o the ton. .\ sample from
one of tliede|iosits in .Miller (iulcli, tiicnt lotted above, showed no trace
'.if jfold or silver in an assjiy by i'rofessor .Muni , while one by .Mr.
Ollicer showed irold n.id ounce to Hie ton and a irai.'e of silver.
On Hunter (feck ate similar ittii»rc.i;tiatiotisof sulphides, vvhieli are
ehielly pyrite, ntarcasilc, chalcopyrile, JUid sottieliines iiyrrholito. Al
ono i)oint ii tunnel has lieeii driven on a black, carbonaceous shah'
wl.'ieh is interbedded with diabasic lull'. This shale is in portions
silicilied and contains much pyrite. I'mlerthe microscope it isfotind
to be orii;iiially calcareous, but Ihe imIcIIc has been largely replaced
bv pyrite, with some chalcedoiiic silica. Thisroidc is eliiitiied lo have
shown siillicicni v;ilites on assayiti.ij; to make it ii low-5,'rade ore, but
the jissav b\' iheSiirvey showeil o.lio ii'old and o.ii.'i ounce silver to the
ton; however, this was, nnfoiM iinately, of a specimen and not of a
Ciirefullv selected itssay samide.
GENESIS OK AURIFEROUS QUARTZ VEINS.
It has alretiily been noted that there ate in liie iroltl-beai in;; rocks
of the Vtikon district two chief sots of ([imrtz veins, one of which wtis
fornieil previous to the scliistosity and one subseoiiettl thereto.
if
II
298 (ii:oi.()(;v oi' tiik vikon gold nisTiiirp, af.aska.
^ u
Ilc.-idcs llicsc 1\v(i cliii'l' si'is. ilici-c ;iri' riT(|nciit \ciTis si'MiitTcil lici'o
iiiiil tlu'i'c tlii-iiiiL:li till" yiiiiiiucr idi'ks. Tliis is wliat slmnlcl lio
f'xpcclcil, since silica is cvci\ where heintr taken inlo soliilioii liyurdi-
nary alkaline walcFS anil |)i'('ci|)ilateil I'nmi llieni, so llial ticw (ie])()sit.s
ar(> roiidiiually rorinecl in favorable ]ilac(>s. liiil lliese yoiinuest veins
ai'c scatlereil and belontr In no delinilc syst<'ni ; and. so tar as knou ii,
llieyare of no econonne iMi|iorlance. The veinsol' I lie I wocliicl'sels in
(lie schist use I'oidvs, liowexer. are c\1 1'ciiiely nu Microns and i iiiporlanl ,
and both sets appear, as deserilicd, to he aiiril'crons. The older set;
has been so sheared t hat its relat ions are ureally oliseui'cil : (herel'oi'o
llie yonnircr set, which has been left nudist urbcil. olVeis the best
facilities lui'slndy as to nalnre and origin.
'riicse yonni,'ei' \-eins lia\c a close and evident connection with aci<l
dikes. In lioih the l''orl.\ mile and the liii'ch Credv districts llii'
\eins. by addition of felds|)ai'. uraile into aplile. IJetween the aplile
anil t he quart/, lliei-e is a iH'i;niat itic si aire, but the peninal ile is line
in text ure and is not very abundant . P'roni thecoarse feldspai-i|nart/.
ro(d<, or aplite. there is a f;i""litl'"" into finer-ii'rained. more typical
aplite, which occni's in laru'e quantities. One variety of this has a
firoundnniss (if irranular quartz, which contains plienocrysls of feld-
S|iar luucli lai'jrcr th.m the quartz grains, but still small, and often imt
abundant. Theie is. in short, a firadual transition from quartz \eiiis
to 1y|)ical aplite, and it follows fi'om this that the conditions and
manner of forniat inn of ipiartz veins and aplite were not eiil irely dif-
ferent, but passed into each other by \-ery slight moililicat ions. Tliei-i*
is, thei'cfore. no sharp line between so-called dikes and so-called veins.
•ii;.\.\siriii.\s liKTw r.HN vi;ins and ii.ni;ihs kucks.
'J'here has always been a tendency to rc^ranl \enoL;enoiis or intru-
sive masses of minerals formed in cracks or tissnres in oldei' incks as
nat'n'ally di\isilile into two well-delined classes: one foiined by a
eoolini;' from a molten condition ami one by a deposiiion from solu-
tion in waters, ami these classes ha\e been called dikes and \eins.
The concept ion of this sharp dislinction has ai'isen because, on the
one hand, many dikes olVer indubitable e\ idence that they have bei'ii
formed chielly by cool inn' from a molten condil ion. w hile, on t he ol her
hand, many \'eius. by I heir laycrini:', comb st met ure, etc., show cleai ly
that they have I n deposited from waters. .Moreover, thi' material
of which nwmy dikes ai'c made up is ideiit ical. or nearly so. w ii h I h.ii
of nuiny lavas which are pmiied out on ihe surface; and I he pi'iicc>s
of (he foi'iiiation ol' the-:' la\ as is qiiile open to obsei'V al ion. < 'u i he
other hand, the deposit ion of \einsaml \ein material from clrcnlalini;
waters is a jiroccss which nuiy be everywhere oliscived. both at the
surface and, to belter adxantaLT'
'c, in unileiuround e\ca\atious.
\\'ith (his preconceived idea of the utter dilVereuce in manner of
deposition of the two classes of ilejiosits, it has hapiiened naturally
(ii'.xr.sis OF Aiiarr.iKus (,m mm/ \i.i\s.
■_'lil»
flint nicks ])M'sciitiiii:- ;i |icclVct I i-Miisit idii Ipciuccn ilir iu(,li;i\i' loiii;
been ;i SiHII'<-c of i'(ili>iil.>i;ihlr |M'l'|ilcxily Mini (•(iiilclilinii. Tllc-c
transit idii nicks jii'c cliidly kiiciwii as iicirnial ilcs, and have liccii
rol'crrcil by suiiic to ihc dixisinii n\' diko and Ky soinc In Ih.il <>(
veins, since some nliscrv cis pcrcciv i^l dcar'ly cliaraclcri-.t ics |i(iiiiiin.i;
tn an igneous ni'lyin and sliuwini;' rckilion In uranilcs and iillicr
crvslaliinc nHd<s, ujillc nliicis witc nnii-c part icidaily iMi|i|-cs'- i witii
feat urcs indicalinu' an ac|iiciius nriirin and a cinsc alliance in .- dinary
veins. 'I'll is (dass nf tfansii inn rncks is nnw. aClcr iMn(di si nd\ . lidicr
undci-sUind, and llic npiiosini;- c\idcnccs lia\c' 1 n rcccmcilcd by llic
latest and iiesl essays nn the snlijecl. winch base Iicimi wiilten by
C'nisby and l-'iillcr,' linitru'cr.- and Williams,' || is, in ilic main.
ajir I by these writers, as well as ollicrs w lin liaie |ircce(|ed llicm,
thai the t'nrmaliniinr Ihe cnarsely cr.\ >lallinc aizLii'i'^ales ni' (|ii;irl/,,
fohlspar, ami other nuiieials, knnwn chiclly as |pe^maiile. have been
formecl under enndilinns inlcl'mediale belween llin>c j:n\ei'llini;' I lie
foi'malinnnl' acid iyneoiis rn(d<s, like u'l'aniles, and llmsc lidxciiiini;
tlie deposit ion ol' simple (pniri/, veins, 'I'l'aiisii inns nf pcLrmaliie lo
quart/, \eins, showinir alisolnic ami uniform uradation from one in
tlie olhei', liavi' been noled by Crosby and I'lillci.' Williams," and
\'an Ilise.'' and transitions or eviijeiil clcsc and constant relations
l)el\\('cn pcu'inatites ami uianilcs lia\e been iioPmI by (lusliy. ib-oir-
.irer, \'an Ilise. and Williams,
'I'he enndilinns nmler which pe^nialitcs ha\c fnrme<| have been
named acpieo-iiiiicniis. In siutiily their ititcrmcdiaic pnsiiimi bciuccti
the cnndit ions iiiiilcr \\ hi<'h (U'llinar.v crystalline rocdis have foriiicil
and tlinse jjovcrnilm' Ihe deposition of ordinary veins, .Ulh(JUi;h
lliis lermiiioloiiy may be useful at presctd,il appears probable that
a more cnm|dcle cnnceptinn nf the enndilinns under which intrusive
rncdis lia\e fnrmed will show it to be art illcial ; and lhal.,iitst i:s it
lias been found itiipossibic l.i divide all these intrusive idies ifto
two well-tnarkcd divisions it\' aipicnits and ii;iienns, nr veins aid
dikes, so ii will be fniind impossible to ilividi' I licm into t hrce sin ip
(dasses. a(|iieoiis, ii;ncoiis. and ac|iii'o-i^ticnns. ov veins, dikes, .-.nd
lieji'iiialiles. It is siilliciciil Iv piovi'd that so-called iL;'neoiis rnid<s
have coiisolidalcd in I he presence ami pari ly Ihroiiiih the agency ot"
water, while maii.v so-calleil ac|Ueous i-ocks or \ eiiis have been f(U'iiied
only bccaiisi' the soliilioiis which d( posilcil them were in a liiirhly
heated coiKli.'on. a;id so posses.sed especial pro|:ert ics. That there is
no sliai'i> line of demaii'ati(Hi between dikes and veins has been
'Ori(tiii"t pi'l-'iii'itiii', liy W. ( i rr,.sl.y ,iii.l M t. t'lilln-: .Viii. (i,'..lMi.-ist, Vnl. .\M.\, N..,:i, |.. I ir,
'Hif Miiu'ralipii ili-r S.vi-iiit|ii-u'iiuitii:.-iliiac- ■|i-r si'iilii[.i'wi'«i>.lii'ii ,\ui:ii- \iiiil Xi|ili>'liii-.viiijii',
l.y W. C. Hi'mu'lT'T: X.'il^.lir. liir Kl-y-l, Vi.j. XVI. |M«i, iMi :.'t.-i-:il.V
aiirigin "f M:iryliiMil |..'i,'iimtiii's, liy (), U. Williiini-: l'"!!!!'!'!!!!! Ann, Kept V. S, cir.il. Surv.-y,
1.-V1-), p, ilT.-i.
<0)i, I'll,, iiji. I.v;, lT:i.
•Dp. i-it.. p ii;!i
•Sixteenth All" H.pi, r. S. (l...! Survey ravi I. Imm; p. li-ss
^
-*'
5 4^
■I
.•{()()
(il'.Ol.OdV OK Till'. YCKOX (i01,l> DISTKICT, ALASKA.
..il
li '•!!
]Miiiili(| ciii'i liy Criisliy,' while \'iiii llisc- lias rciiiai'kcci iipdii Ilio
improliahility iif any ilt'liiiitr (li\isii)ii hciwccii (lie a(|iic'oiis aixl
iiriicDiis |)niccsst's at iiindt'ialcly rciiinti' dcpllis, wlicrt' the iiicfcasc
of pressure ami leinpei'al lire must j^hc siic-li irreal alisni-lteiil power
to li(|ni(ls: aii<l both these wrilei's iM-ileve that in the \arious sta;;es
ot '^irailat i<pii heiweeii the prepoiideratinj; a;;eiiey ot' heat and the pi<'-
]iondei-atin^ aj^eiiey of water ail the phases ol' pe<;iiiati/.ati<)n may he
explained, and that thus all peirmatite is due to a moderately nni-
I'orm cause. Williams, indeed, has divided the Mai'ylaiid ])e,trmatite
into two classes, one lieinj; of acpieons and one of iirneous origin : yet
these lia\e often idenlieal I'haracters an<l occur close tojiclher, and it
isditlicult to iindci'stand how such bodies can have been produced
by processes dilTei'ini; so widely as to desei-ve sepai'ale names. Cuii-
ceriiin^: the ori^dn of those veins whi<'h li(> considers iijncous, liow-
e\-er, Williams's \iews are, in the main, in a( rd with the other
opinions already tciven and with those held by the jiresent writei-.
In rejraril to the relations between pejj;matites and icraliites. the.so
views are .so clearly and forcibly slated that the\' may be (pioled. ■'
The writer's coiu'eiptidii ef tln' relatiim iK'tween tlicKo iiitnisivc |H',:;iniititi's iiml
the ;<raiiite witli wliicli tliey are associateil ilecs not iiiatcriall.v (iitVer t'rDiii tlie
cimiepliiins i)f l)c Beauinoiit. Leliiiiaiiii. and lirewr. As Lelmiann anil niivuy
others liave distinctly pointed out, a Kradually solidifying; niannia tends tlironi;!!
the processes of crystallizntion to become more and more aeid and at the same
time more €anil more liciuiil. The water and otiier mineralizing; ft;;ents whicli all
aeid niaumas contain become Kiadnally excreteil and concentrated in the residual
jiortion, since they can not enter directly into the conii)osition of tiie normal
f^ranite. * * * Tlie writer therefore interiirets thoso pegmatites which liy
their mode of occurrence ami association strongly iiulicate an ikuoous character
as the i>roducts of the residual, and tlierel'ore most aciil. ixn'tioii of a granite
magma liigldy charged with water and other miiu'ralizing agents. .Such a sili-
ceous material, in a state intermediate between fusion and solution, has lieen
iniected into fissures and there crystallized into very coarse-grained aggregates,
not necessarily througli any great slowness of this jirocess, but rather in virtue of
the aid to crystallization alforded liy the al)undanee of mineralizers present.
THE <)|{I(il.\ ol' DIKKICKKXCKS I.N lO.NKOl'S HOCKS.
The transition in the I''orlymile ami llircli t'reek districts of ai)lites
thr()ii;j;li inlcniicdiato [)Ofj;niatilic rocks to (luartz veins is a case strictly
analof^ous to tho casus which have hoeii cited and which have given
ri.so to tlie views inferred to, althou}j;h in tiiis cas(> the pejj;matitie
rocks are line j^rained and relatively rare. On Fortyinile (.'reek, how-
ever, tJjo Iran.sition from (|tiartz veins to a])lite is not more eoiniilelo
or remarkable than the transition from aplile to acid .ufranite, from
ncid Ki'ii'iilc lo basic granite and diorite, and from these to succes-
sively moni basic i-ixdcs, until tinally rocks consist ing essentially of the
ferroniagnesian and the metallic minerals result. All the ditl'orent
• Oil. lit., i>. im
»Oii. i-it., p. list.
' Op. elt., p. flW.
"^
Sl'IKII.I
liKNESis OK Ariiii r.Kiiis (.;rAi;iz \kins.
301
Viiriclics oi'cui' ill llic same iiri'ii us dikrs wl.icli li,i\c Imch ini iikIciI
sucrcssivi'ly iiii'l wliicli cut (nic aiinilicr. In view of this rciiiiifkjilili)
ti'aiisitidii and ol' the I'luisaiiiriiiiiity hftwccn tlic ilill'ffciit \ ai-iii jcs,
wliicli lias Ihm'Ii pointed oiil more fully in tlie detailed eoiisideral ioii
of tlu'se dikes, the liypot liesis siif,'t;ests itself iiniiiediately tliat all tlie
rocks liave in some way a eoininoii ori.Lrin. and thai I he cliiVei-eiit
pliases liave sepjiratcMJ out under jfradually clianiiin;; eondiiioiis.
Ill liic lifjlit of tlie most modem peti'oi;ra|)liy it lias eome to lie
rtH'ojjjiiizeil thai there are no sliar|) lines of division hetwei'ii thedilTer-
oiit ii^neoiis rocks, for one variety passes into another so ;:radiially
that the limits niiist lie drawn arbitrarily, and in some cases the best
classification whicdi can be made seems artilicial aii<l almost unde-
sirable. Tliis jii'adat ion, however, does not in itself ^'o to prove any
hypoliiosis as to the orii;in of the rocks. 'I'lie possible hypotheses
as to orijiin may be divided into three classes; those which explain
the dilTerent [)hases as formed by sejn'cjjation from a more unifoini
nia^ina: tlio.sc wliich explain them by the mixture of unlike iiiai;mas,
and those which assume that there has been no iiiipoilaiil chanire. and
that the roitks were esseiit ially in the same condition a,s now at the
time of the earth's formation, 'i'liese three idasscs of hypotheses may
beconvenieittly called the liyiiothesisof sef;rei;ation ordilTerentialion;
the hypothesis of synthesis, and the hypothesis of orii;iiial heteroLre-
neity. Coiisideriiiir eacdi one of these hypotheses, however, it is evi-
dent that there must in any case be transitions from one ro(d< type to
another, since liard and fast lines are iiniiatiiral. l"or instance, takiiii^
the extreme views, the same transit imial io(d\s can be obtained by
mixtnre in dilVereiit [iroportioiisof an orii,'iiially a<'id and an oriirinally
basic inairma, as by se};re}j;atioii in dilTereiit di'irreesof [lert'ect ion of an
orifjinally interniediate mairma into more ai'id and more basic parts.
The true cause or causes of the orip;iii of dill'eieiK'cs of iuMieoiis rocks
iimst be sought for by more detailed oliservations, which may be
brouj^lit tojittlhor to in-ove some definite law or laws. The discovery
of lliese laws depends chiefly upon the accuiiiiilalion and comparison
of facts; and in this work it iiiiist beheld in mind that there is not
necessarily a sinjile universal law, that it would be (p.iite unlike the
complexity of nature if tliis were so, and that it may well be tlial a
certain law iroverns in .sfime cases and iilterlv ditfereiit ones in others.
TIIK IMiOrKSS ol' Dri'lT.UKNTI.VTION OK SI'.(ilU'.(i.VIIo.S.
All of the three jiossible general hypotheses which have been named
as aiiplicable to theorii^in of rock dilTercnci's have been maintained
bydiU'erent writers. Lately, however, the tiie<ny of dilTcrcnliation
or segrejjation has been most advocated, and there is a tendency to
exiilain all ij^rneoiis rocks as ,sei;re,uations from a conimoii mau'ina.
'I'lie ])rinciple of the seiireiration of materials in a fluid condition
is well known in the laboratory and is beyonil dispute. .Materials
r
ill
,")(l2 (illol.DliV (iK TIIK Yl'KON (idl.lt lilSli;l( T. ALASKA.
iiil iiiLiili'l\' iimiil;Iim1 in n soliit ion iiiay m'|i;ii;iI<' iiiin ili>i iiici Mini |ii'r-
I'ci'l iTysliil> ;i pi I'ss which rciiiiii'c^ m ri)ii--iilriul)ii' iii(i\ cniciii of
thi' niiih'CMJi's; miiiI the crysliils <i\' iiiiMiTiil \iiiis, iiiiil I'M'ii id' i.i,'ii('iMis
I'licks, iiiii>l 111' I'liriiirii ill iliis \\;iy. In llif iMlinraliiTy the prniTss of
srirri'L;.-!! ion rrri|ii('iil ly jh'Is so llml Ihc in.-ili'iiiiis .-irc scpiiriili'il not
(inh mil) siiiixli' crNslnls, hiil into lni
Mi'lii's iii.'iiic III) of iiiiinv liki' I'
Ifils; ami the iiiii>--i's of the ililViTiMit miin'i-als arc more or less per-
fect ly scparatcil. in ilic sMiiie way it occurs in ininoral \ciiis that
cerlaiii minerals .-ire sei;ic^atcil in iariie liuiiclics in parts of I he \eins,
while other minerals are colleelcil into other parts. In iiincinis rocks
lliere are ollcn small patches where certain const iliicnts an nceii-
Iralcil ill such a way as Id place it hcyoml iloiilit that they lia\ e sc^re-
jralcil ill the s.imc iii.-iiincr as a siliL;'le crystal sc|ia rales out from solu-
tion: .■iml from these small patches there is a urailat ion to lari;'cr I'oisk
masses, which have markeil ililVcreiices in si riict lire ami eompusition
froiii the rest i.f the iiriieiiiis holly of which they, Hex eri heless, I'lirin
an essciit ial porlion. It is thus louml that in a laritc igneous mass
ililfereiit port ions have slight ly ililVei'ciit characters, ami theiiica nal-
iirally follows t hat t licsc lariic ililfcrciices ai'e iliic to t he same i;encral
causes w hich has c pioiliii'cd the scL;rc,uat ions of minerals on a small
scale; or, on a still smaller scale, the scerc,'.;;it ion of imlixiiliial cr\s-
lals. !•
ollowiiiii' this lint
)f thoiiirhl still further, it is pen
•ei\eil that
ililfercnti iii'iicoiis rocks in a ;;i\en district, while showini;' throiiulioul
certain constant |ieculiaril ics, all ,u;railuall\' jiass into one aunt her; and
the expla
iiat ion iiat 11 rally siiu'i^ests itself that t hesc dilferiiii;- rocks havi
oriuinatcil hy t he same process of sejiiciiat ion t'rom some iiioi'c uniforiii
iiiauiiia. I''inally, modern iielro.nraphic research and comparison have
shown that, altlioiii,di the classes of rocks are essciit
iall\ t he same in
all |)aits()f the world, all tlie rocks of a jiiveii district, taken collcct-
ixcly, often present cerlain constant dilferences from those of iieii;li-
boriiii,^ districts; and hence t he t lieory of se.urei;al ion or dilfereiiliat ion
of the oriuinal coiniiion niaunias of these dLstricts from an ori!j;iiial
universal mai^ma has been coiicci\eil.'
Till: rlii;.MIr Al. VAtMAIIitNS I H' lirKKS.
Ill seek ili,ii proofs for these liy[)i)t lieses, we should iirocccd from the
W(dl-estal)lished pheiioiiiena of sejiicnat ion on a very small scale to
eases iii\ olviiiii; siiccessi\'ely lar,L:;er and larirer masses, 'riierefore the
eliaractcrist ics of dikes and other masses of intriisivo orii;in whose
boundaries can be traced oll'cr a very att fact i\e field for study. In
these rocks it is often found that there is a marked dilferciice, both
cliemi<-al and structural, in ililfereiit portions of the same boily. 'i'he
slrncliiral dilferences are shown chiclly by dilfei'ciif dciirees of crys-
lalli/.alioii; and usually these ditl'ereiices e\i(b'iitly depend directly
upon the rclati\e proximity of the wall i k, those |)ortioiis which are
.1, 1'. llUiillK'^, Tllf i.l-inill ol ii;ri,'.JU,, l-,»k^: iillll. i-ili..!^. S,.,', W'il.-llillKtoll, Vol. Xll, p, 1S.V
V
(ii;NK«-is or .\it;iii;i;()rs <,.ia1!I/. vkins.
3i i;?
iicMi-"'-.! 111.' Willis liiiMiii;- ill ^'rii.Tal ;i liiirr I. •Mini. ,-iii,| iii,,v,. more
ll'lllulr llcillL; iM.IIMT. Il is I'll-iir llllll lllcs.. i|i|V,.|,.||i-r^ mT ^IiiicMlllc.
\vliiclicli.|MMii| MPiJiicTi'v II I Mill till' iinsltiiin .if I lie \\;ill r.i.k, .iiiiiiiMl.-.l
sllliM'i|l|.Mll t.i 111., illlrllsiiili 1.1' till' .like. ( 1.11. ■.•111111- 111.. .■Ii.iiii.'.il
.li^V^l•ll<•.•^^ ill .liKr>ill|i| ..lliiTilili||>i\(. im;i-.-.'s. il 111,1 \ liki'W i>.- l... •..liil
llial. if ill iiiiv iliki' ..r .iilicr ini riisi\ .. mass ..I' ii;iii..ius in.'k .■liciiii.-al
\ aiialiiiiis sliiiw (liii.ci and (•.iii^lanl i.'lalioli l.i |ir.i\iiiiil y t.i llii> si.j.'s
or ct'iiliT. il is sliiiii;; cviilfiiiT. aiii.iiiiil iiiy- aliimsl (.. |iiniir. ijial tliis
clii'iiiical vai'lalliiii caiiicalMiiil siili>.'.|iiciii i.. ih.. im iiisi.in mi' i li.. r, ..^k ;
riirlliiTiii.ir.', |)r.>\ idcil it .•an li.' |ir..\..i| thai lli.'>.' \ aiial i..ii- an^ in.l.--
p.'ii.l.'iil ..r 111.' .'Ii.'iiii.'al variali.iiis in lli.' wall in.'k--. ii is \.'i\ slr.ni^'
<'\ ill. 'life thai tlii'V lia\.' aris.'ii by a iinicfss .iC s.^u'i.'iral imi. tin the
(illi.'r lian.l. la.'k .if siidi rciatinn is im |ir.nit' airainsi I lie iiii>siliiliiy .if
si'U'r.^ual i.in.
l)r. (I. II. Williams' lias .Icsci'ilicd llir ciiiilai'l |ili.'ii.iiii.'iia ..I' .lik.s
llitriisiv.' iiil.i iiiii'M s.diisls anil liiiii'sluni's in Ni'U \nyk. in mhh.' nf
llu! narr.iwi'si dik.'s I ln' iial in.' ..f I lie ('iii|il i\ .• r.i.'k (.li.irii.^) i-. .•.in-
.sidt'ralily all.'M'. I ii.'ar I lie .'.in lad. < >ii.' .if I li.'sc .lik.'s was .mly .iii.--
fljjlilli .if an ini'li w i.lc, s.i ilial I li.' fill ir.' w i.li li was .•niiiain.'.l w iiliin
llu'lliiii si'cliiin sludic.l. 'I'lic iiil iiisivi' inat.'iial cunsisli'd ..f Innii-
lilcnd.', lli. Mil.', apalili-, an. I |ii'.ilialil\ s.'aji.ilil.'. ami tlic liiiriilil.'ii.|«>
was .•nil. •.•Ill I a I. 'I I a 1.1 111;' III.' .'dii.'s iil' I lie dik.', .il'l.'ii slamliiii; |M'r|p.'ii-
.liciilar I.I ils walls. In lliis cast' llic w..ll i.ick was liiiicsi.in.'. I'luf.
A.V. I.awsun '•' ili'si'iilics ciTtain dikes in tlic ISainy Lake it'^ri.'ii wlii.-li
sliiiw in a iiiai'kc.l dcuri'i' variali.nis nut only stnii'tiiral lint also iiiiii-
cralii.^i.'al ami .•licinical. ami llicsc \arial inns a|i|i.'ar \ cry .•.nisianl ly
in dilTcr.^nl dikes In lia\ .• I li.' saim' I'.'lali.ui l.i lli.'wall r.i.'ks. i''iii'
examiile, in a dike I." i feet wi.le there is a ura.lal i.m in leMiire from
an a phalli I ie rock ai the eon tact to a eoarse Lraliliro or diorite in ihe
eeiiler. Ill 111.' same dike there is a miii.'ialoiii.'al \ariali.iii fr.nii a
(|iiarl/,les> rock ai the dike wall to a iinartos.' one in the eeiiler, ami
also a yra.liial change from aii^riti' to hornlilemle as the mi. Idle of
the dik.' is approached, tou-cthcr with other w.'ll-niarke.l dilVcreiu'cs.
('h.'iiiical analyses show that the rock in the mi. I. II.' .if the .like e.iii-
tainsalionl Inpcrceiii more silica than Ihat at I he >i.lcs, a .lill'.'ri'iico
w liich is siitli.'i.'iil to SI 'pa rale the parts iiit.i I wn .list in.'l r. ick sp.'cics.
I'r.if. ,1. T. I.l.liiiiis ' olis.'r\ .'.1 in a certain .like that lli.' iVrromaiiiiesiaii
elenicnts had liecii part ially I'onceiii rai.'.l aloiii: I he siiles. aii.l ref.'i-s
t.i I.aji'orio as having iiiaile the saiiii' oliser\ at ions.
Sir .Vrchilial.l (ieikie' has lirietly descrilied certain iiitriisi\e sheets
of dialiase in the liasiii of thi' Firth of I'"iirlli. Near 111.' coiita.'t with
sandstones or shales Ihese diabases ha\e an abiiiidaiicc of oliviuu,
'Am. .T.nir. Sri., (i.^t., Iws, M siTi.^s. V..1, .X.X.XVl.p :;.V.i.
■Pi^tr.vmpliii-al ilill'iTi^iitiuti'iii nf .-.•i-tiiiii ilikrs ..f tli" Hniny I.:ikr n'lti.Mi: Am. (l.-.plnttist,
Miirfh, IMil. V.il. VII. IP. 1.-hI.
»Tl.onriirj,i,,f jir,„.,„i.,;|.,„.l(s: HuU. Pliil''.^. S.I,- . Wa~liiii>,'t..n.V,.l. XIl. j,. l.W.
< •r...\tH.«ik nf (i..|iloKy. :!,l ..clitiiill. l.-'.l.l. p <>'■'■
I
1;
m\
304
(ii;(iI.u(;Y (iK Till'. VI'KON (iOI.H DISTNK'T, ALASKA.
wliicli iliiiiinislics ill |)ru|Miiti<)ii as tin' ilislii riciiii llii' I'oniaci is
increased, until in lliecenterdrilie slieels il clisappears. 'I'lic inlerior
purls are also Con nil to lie mure aeid than the exterioi'. Sii in tliis
ease the wall I'oek is ol'teii samlstolie. it lines iKil seem pfolialile that,
it ean lia\e hail an.\' inlliienee in iiiai<inir the Imrilersur the sheets nmro
basie. sinee if assiiiiiiation of the wall mek had priidiieed any cheiii-
iealililVereiiee in the ifrueoiis mass it WDiiid naturally lend to ha\ e t he
opposite elleel and make the liorders more liasie than tlie center.
Kemp and llollick,' in de.scrihiny: the conlael of a mass of intriisise
frraiiite with limestone, h;ive remarked tlnit t he ^rranite liecomes more
hasicasllieeoiilacts.irejipproached, the|iroportioniiliiyroxenelieeom.
iiiy much greater.
On the other hand. Mr. Ha},'iie- lias deserilied a dike of {.'ran Me imiI'-
pliyry in limestone in the Kiireka dist rid of Ne\ada. In this dike tlio
walls are j;enerally more acl:! than th" center and carry less ferro-
nia>;ncsian minerals. The dill'erenee in amount of silica, liowever, is
slijrht, the extremes falling i)rol)al>l\ within I jier cent of each ollici\
Kouqili'' ' has also deserilied certain dikes the wallsof which are more
Soiceous than the ci'iitral part.
From the fon'fjoiii}; oliservalions it apjiears that there is often a
systematic \arialion in II hemical composition of dikes, which has
a constant relation to the proximity to the wall rocks, and that, as a
nilo, where there is such \'ariation the outside of dikes is more liasii;
tlian the center, altlioujih sometimes the reverse is tlieca.se. .More-
over, ill many cases this variation can not lie ascribed to assimilation
of the wall i'ii(d<, and must be explained by sonic process of chemical
seirrenation ; and from tlieielalion Just iiointed out it seems jirob-
able that the causes of these scirreuat ions are ditl'ereiices in 1eiii|iera-
tiire, since, as a rule, those jiort ions of the dike nearest the wall rocks
would become cooled most i|uickly, althoujih in certain coiicei\ able
cases the reverse would happen.
utiiKU tn.' srcri:ssi()\ ok i.avas.
Where lavas liavt> been erupted at ilitTereiit jieriods from a sin;rlo
volcanic center, pet rouraphers have thoujrht to have discovered ileti-
iiite laws of succession, sliowinji; thai in the reservoirs beneath the
venl the molten rock was underfioiiii; a jirogressive chaiifie in chemi-
cal composition, and this <*han^i;e has been asci'ibed to sef;rei;atioii or
(lilTcrentiation. 'I'lie usual law of sllcccssion, as interpreted by
IddiiiKs,' is that the series bcirins with a rock of avera^re composition
and passes tliroiii^h less siliceous and more siliceous ones to rocks
extremely liij^h in silica and others extremely low in silica; that is,
' Tlif ijranitc at MnniitK Atliun aiul Eve. Wiii-wick. Oraiij^c ('(tunty. Xf-w Yurl^. an<l Its i
tai't phclinini'lia; Ani:-ilrs Xt-w Viprk .\<-aii. Sci.. V-.I. VII, j). •►IT.
■' Mnii. r. S. Ui.i.l Survi.y, V.il. XX, (ii..>|..u'y „{ the ICureka District, ii. :.".'.'<.
^ Sautorin ct si's (.''ru])tiuiiH. Paris. l.sTl'. \t. ;tii4,
<()p. tit., p. U").
h i!
(il'.NKSIS (ll- VURII'KKiilS i.HMT/. VI.INS.
;5o:i
tlic scries (•oiiiiiiciici's u ii li a iiii'iiii iiinl nuls \\ il li iai rciins. I'lmn
si 111 ill's ill llic ri ii|il ixi' iiirUs 1)1' Niirwiiy. l!riiLr;;i'i' aU" 1 liniijrlii ii> lia\ i'
ili'li'i'iiiiiii'ii a ilcliiiili' law 111' sni'iM'ssiuii, hy \\ hirh llic iipcks |M-(iL;ri'>M'il
rroiii tlic iiinsi liasii' tollir II livt ai'iil \ afii't !(•■«; ami tiriUir.' I'miii a
sillily (il llii' i;riifi'iis I ks in Srollaiul ami iii'i;;lilMiiiin.' ifi,'iiiiis, lias
mini' ((I I 111' saiiii' u'i'iii'ial I'lPiii'liisiuiis as In I hi' siu'ci'ssimi. Allliiiii(,'li
till' iilii'iniiiiriia ili'sri'ilii'd ami llii' laws licilui'i'il h\ ijicsi' ami uIIht
i)hs('r\ CIS ilillVr in ili'tail, yd lln'\ all si'i'iii In iiniiii in a ili'liiiili' nnliT
III' siH'i'cssioii ill la\as piniicil (iiit al ilillVii'iiI liiiirs in llic >aiMc vnl-
I'anii' ri'j;iiiii; ami il' lliis is I'slalilislu'il, it pniniN liihi'i' in I'lii'iniral
si'i;ri'iral inn nr In a sysli'inalii' ni'i;:inal ililViTf'iii'f: ami nl' llii'si' Iwn
alllTlial i\ I'S llli' rnl'liMT nll'iTS liv far lIlc TcWiT (lillicllll ics.
('uni'iTiiinf: llii' ilill'i'ii'iii'cs in llic natilii'iii' -.iiicosinii whii-h lia\i'
lici'ii nlisi'i'Vcil al ilill'iTi'iil \nlcanii' ri'iiii'is. il may lie nniarki'il llial,
cvi'ii willi a lixi'il ili'liniii' law nl' si'U'ic^ialinn. Ilii' ni'ilci' nt' iTuiilinn
wniilil III' ililVi'ii'iil in liilTi'i'i'iil rasi's. hi'ini^ ilriii'iidi'iil 'i|inn a j^rral
nil 111 Iiit nf ilisi iiiliiiiL;- ami alii'i'in^' iiilliii'iici's, many nf w liii'li ii'ailily
sii;r;;i'sl llii'iiischi's. Imli'i'il. il wniiM lir nnnaluial if any iinil'nrni
I'lui'i- sliiiiilil nlilaiii i'\ I'l'.vw lii'ir; inil liy liri nl ami rarcfill si inly llic
general law slimilil lie fniiml wliieli wmilil in a laiiic iiumlier nf cases
jircvail n\ cr all nlliers, ami wniilil lie |ieil'eil ly illiisl rated w Inn enin-
plieal inir liilliieiiccs were ahsciil. while in nilier cases it wmild 1 me
cliaii;j:cil iinlil nflcii the succcssinii i>\' lavas in a ,i;i\cn distriei wmild
he iliiilc witliniit a I'ccnuiii/.alplc plan. The laws already ilcdin-ed li.\'
Iddiiijis, l>ri'i>;^'er, <;eil<ic. and nilicrs ditVer in dciail, Iml osciitiallN
ajri'cc ill this, Ihat any fnek tiia^'iiia iiiidcf l'a\nra>ile cmidil inns lends
In sc|)ai'atc lull I a iimrc hash- and a innrc acid |ini't inn: and in view nf
Ihc cniisidci'iltiolis which have liceii poiiilcd mil, this may he aceeplcd
as {111 jiypiithcsis which, alllimiKli m'l yel alisnliitely prnved, isslrnimly
Sll|)pnl'lcd liy facts. The aceeplaiiee ii\' this cnnilll--inn as tn the
cnicacy nf se.Hrcu'.'ll inn In priiilllce dilVcrclll inek t.\pes lines lint cniii-
pcl lielief that all rnck types ha\i' thus nriiiiiiated, ni- that the types
which have lliiis lieeii Inn 1 ha\e sprung- finiii unifnini iiiaLrinas.
s.Miin: cK riiK sKinii;i;Mio\ I'liei »>sns.
('oiieci'iiiiifr the prncesscs hy which the separatinli nr seLrrc^atinll nf
the imire basic fiinii llic iiinre acid ruck eniisl iliieiits takes |ilace \ei'y
little can he said, lirtiirircf, N'niit. and Iddiiius' apjical in fniin> nf
innleciilar flow t he applical inn nf \\ liich is nnccrlaiii. The law rejrard-
iiiU' (his is kiinwii as Snret's principle, and is llial innleciilar cniiceii-
Iratioii iKiiy he caused liy dill'crenccs in teinperaliirc. limirtrer ' alsn
siii;ficsls that ill the same time a partial cryslalli/.atinii iiii.i,dit set in,
and ])rndiici' sofjrcKalinns i<( the ninre basic iiiiiicrals.
'IilditiKH. oji. fit.. V ViS.
^Iddinns, lip. ■■!!.. ii. 14H.
'Op. rh , p. t.V.i
* Miliums, oji. I'il . ji. 1:^1.
IS GEOl., VT 3 -(»
'I
'^^
II '
V
,'(ll(i (iKiil.iKn iiK IIIK YIKON lliM,l) DISIIMC T, ALAMKA.
Till- rlVici iicy ■it' iiiiilc'ciihir' ll<i« lia> l>"cii miuM'cI in llir laliurjilitiy,
aiiil is a<'i'i'|)l('il a- Ih' lll(■arl^ liv wliii'li llic ;jiihm1i nf crystals takes
plai-c ill siiiiil idiis ami also in rucks. Mr. (i. I". I'cckcr.' Imwcvcr,
ai'^'iio that iIiIn pfii- ^s^ is sn >l(i\v iliai the scpaialiun of aii\ cuiisiil-
craltlc liiiily III' ruck into iiiorc aciil ami iiiurc liasic |i<irt iniis wdiiM
(icciipy an ciioriiiinis jicriciil. iitlci'ly '.isp-opiirliipnal"' tn all mir iih-as.
.Mr. Ilcckcr also iccuuni/cs as a imssihlc iiicIIuhI uf scy:rci,'al icm the
S(-pai°atiiiii <il' a hmii ii.^eneiiiis lliliil iiilu ilisliiict iiniiiiscilile llMiii-< hy
<lt'<'rcasc in lemperat iiri' ur increase ul pressiiie. I'nih'r the same
iiiidi! imis t hi precipitat iciii lit' Miliils triini liipijiis I i.kes place. 'I'licse
iiiiiniscihlc lliiiils III' llie |irecipitatcil snlid ami the resit lal lliiiu \iiiilil
natiiiall.x separate Iheiiisehei accnvilini: In s| Hie eravity; bii' this
jiriiccss is alsii cmisiilereil tn lie iiicapalile nt pnuliiciny' any i;rc,i,
ailiollllt III' sciirey:aliiill. nil .m-cuiIIII nf the pliilialile \ is'Misity n'' t he
li'jilerial and I lie a|iparciilly liliiiled raiii,'e nl' teinpcral me a\ .lihdile.
II is also piiiiiled lint that cKiivectinii ciirreiils are imavnidalile t'.ira
Very liiiiu (leriiid, since t hey wniild rcMilt I rniii any slight local changes
of leiiipi rat me, ami therefore, even if time were siitlicieiit fur sei;rc-
;raliiiii. these eiir-cnis wmild pre\eiit it l»y a contiinial mixiiii;.
It seems III liie writer. h'i\\e\ci. that, allluni.uli coin eel inn ciri'ms
ill icsei'\ nils of mi.lteii rock must lie nearly alvxays prescni. as pointed
(III! I'y .Mr. IJecker, yel these currents d- not iieees.sarily in e\cry
case operate to i.'ii.v. lint iiia\ nfteii have the nppuslte cll'ect and \k'.
e\t reniely inipnr'anl in prndii.Miii,' scrreaal inn. I'lir i\aiiiple, if local
decrease of ' 'iiipcral lire or increase nf pressure shoiild piiidiice a
.separation of ail orii^inal hninn^eiieous lliiiil into t wo immiscilile lliiids
oi ililVereiil specilie uiax ity, or iiit a snlid and a lliiid, weak iiirieiits
mi;;''' ad to separate the two pails ine<diaiiieall> and mure nr less
completely, accord ill!.' to tic r !elati\ c specific ;,na\ it \ . liy sinli ciir-
rciils t he liirhter parts wniilii lie carried farther than Ih- ilea-, id, and
j( ciiiiceiil rat ion would lie elVecteil. depeinlenl upon the Clint jniiity of
tile ciinreiits .iiid oil the perfect ion of t he t>rii;ii;,il chemical separa-
lioii. 'I'lius Usually near tlie cooliii;; walls of a limlx oi iiiiieniis rock
lliose |Mirtiiins which solidify lirst, that is. the more basic constltii-
I'lits, will lie precipitated, and the c|iiTcnts will coniiiiiiiilly ••nvv^
a\va.\ the r'-.idiial liH:htci' materiai and mini: new supplies of Miii|i!1ei-
fiitiated tliiiil. In this way the eil;>cs nf a ruck mass ■hoiild lie. as a
rule, more !• .sic than the cemer, which is the cnnc'usi n at wliidi we
lia\ t' art'' > cd from the lecnrd • fac's;fiveii aliove. .Mo:e \ ioh nt cur-
n'li'.i, liowevcr. Would carry liolli liutilerand I avicr matcriiils aloiiu:
tii^ctlii'i'. and miLTliI cause a complete minuliny. In this wa\ lluiils
which hail separated inin dilVcreiit port ioiis iiii>:hi lica^iain united
'I'iie ditfereiit prnccsses irniN hi iiiparcd In tliiactiiiM of water on
nick del I it lis at the surface. .\ cnmparat i\ el> uciitle stream tlowiiiL;
over lii'tero;;eiieiiu^ rock fra^m ills liriiiirs alioiit t he sciiaralioii ami
' s.iihi i|iiii'h- 1.11 1." k iliili iit!ii;i .\ .\iu I"! r s.'i.. nil ■„-n. .,. v.'i 111. ivi;. |.|. ■;) in.
t )
.
(;p:m:si8 nr aiuifkhih s (.haimv. \kins.
3n7
assort iiH'iit (if 1 'ir tVii^iiiU'iils .-ic'CDriliiii,' III si/r ,iii'l >|ii'ril'ir Lrr;i\il\,
foniiiiiir at oiu' I'lint ,i li.'d nf ciiaisi' iffavi/l. ami at aii'itln'f a layci'
(if tine sand, and also In lii,u:iii,i;' alimit I'liiicciilraliniis ul' tlii' litav icr
constitilciits I'lMin tlic liiilitcr, wli'ilc a luffiMit taffies almii,' all ilii'sc
liiatcrials ami luiiijilcs tliciii in cinit'llsioii, li'ariiijr np dc|)iisits alfi'ady
.sc|iarali'd and niixinj;- tlicin to.u;<'tin'i' in their niiLrimil dism-di'i'.
Tlir. l'Ul)('KSSl:s n|- sYNTlir.sls I. It MIXl.Ni..
\\'liili'. tlii'i-('roi<'. ditli rriilial ion of scirrcnat ion laki"~ plarc on a
snial! scale, and, as Inoad i;eolii.i,'i<'al laeis imiieate. [nolialily on a
laiir< scale, on tlie other hand, synthesis of mi\iiit; is also known 1o
oecitf in a small \\a\ . and imdotibtedly must someliims allVet lartre
li'.asses. Mf. lieckei' sniiiresls tliat molten mairmasnn!si lie minified
to some e.<tent by violent m<iveiticnts and miufations, sindi jis those
"wliii'li take place in the ]iroeesses attendant niion a \ oleanie ernjil ion.
r,iN I \i r \n:i' vmuki'Io^m.
The simplest case ol' synthesis in the pfodnelion of rock types is
perlij'ps the allefation of wall rocks by intiiisive masses. \\ liieh is
so!,ietimes line to ehiinica' and sometimes to mechanical eanses. In
tiearlv every ease snidi wall rocks .ire found to lie modilied st ruci urally
and chemically, and to contain new const it iieiiis der;\ed Iroin the
ijr 11^ rock. .Ml of Ihi' niimerons cases of coi\tact m'lanioipliism
illilslrate this process of s>lltliesis. Of these, perhaps \\\f simplest
and commonest Is silicitii'al ion. alt hoii^ih in many more ev i I'eme I'ases
simple sedimentary rocks jire altci'cd into sidiists. or even , lassivo
cf.stalline rocks whose characters are indist in'.iiiishal>le 'fom those of
similar r.i(d<s of iirncons oriLriii. < »nt of these nniiici'oiis cascM.f con-
tact meianiorphism a few example-', taken almo>l at r;iiidom. ujll he
siillicieiit.
yii„lil'tr,iliuti.s ill' inill ;'/r/,-.s. -.\t tile conla<'l of the .Vlliany ;rrairite
wilil the scii'ls. <i- ^V. llawes' shows that the schists have become
delivdrat<'d ; -nl silicified. »i. II. \\ illiains notes i hat ncartli n-
tacl of massive diorile with micas-chisi there is an nndoiilned met.-i-
morphism of the lalli'r. isistini;- of an additio i of alnmin;i ami iioii
and a corri'spondinL;' dcci-ea-e in the proportion of ^ilica and alkalies.
This ehanue is shown by i he dis.ippearance of ;l.^ i|nai'l/. and miis.'o-
vlte ami the developmeiil of blot ilc, sillimaniic. staiirolit.\ cyaiiitc,
and irafi'.ct. .\ iiioie complete alteration of wall rocks is that in ted
by Miss M. T. (iardiner ' ,is lia\ int: been induced by the Cairnsiinire-
in-l-'leei ^iraliitc on Silurian f^rils .■iiid -halo. In the shale- leiiticlcs
of .(11 ift/, appear half a mile from the Liranite. while mar the .uranite
here IS a sep.iraiion of iiuari/. miiNi, and plauioclase into separate
|| ip. . It , [i. :l''
'.\iii .ti.iir. Sii ,:iil wrifs, V..1 .\.\l. 1-.-I. p :-'■-
:■ \i.i .I'.ur S ,,.o.-t,. I^^^ :|,I »,-r.. V..I .\.\.N VI. p). -M 'M'
«r..iitu.t alifi-iilioii iivar N.'w Uulli.wi.y; yuurt. .l.mr. U.'i.l. s.h-. I...11.I..1.. V..1 .\I,VI. p Mi.
.'iOH UF.()l,()(iY (IK Till', VKKON OOI.O PISTKICT, ALASKA.
piilclics. Within ;i yai'ds uC tin' f^i-aiiilt' tin- slialts h nic traii>-
fonniHl into a lij^lil-trray, ;;raniilar rock iiiaiic up mostly of <|iiait/. and
nuicli white aixi hi'ow n mica; in this iiirlit-frray rock arc Idack palclics.
Moth i^ranitcs am! sciliincntarics arc \-cinc(l liy aplilc. witli while
mica, ^Mi'iicls, anil t'lui'TnaliiK', the last arrantred iriapiiically. In the
t;rits the altei'alioii is ^'reatcr. Two Inimlred yards IVoni the yranile
the re
mains lirilliant while mica Hakes with bi'own mica and
some tonrmalinc, ami the (|nai-t/ is in lar'jjfc |»ai-t recryslaili/.eil. At pin
yards the rock is coarser and rcsemhles a jrindss; there is mndi white
mica, nesis of l)laek mii-a, and interveiiiiii; palches of qnart/ with
fiarncls ami sillimanite. At the jniu-tion with the <;i'aniie the rock
loses all sii:n of clastic (n-ii:in.
Miidiiiciiliuiis lit' iiilnisin riii'ks. — (>n the other hand, iuiu'inis rocks
themsehes are sometimes modilied liy t he assimilat ion of m.iterials
from the u.ill rocks. (J. II. Williams' notes that the most interest inu'
point in reirard to the .u'al)ln'os of I li<' Cortlainll district is that they
alwavs. so far as oliser\at ion was maile. oc(
nr immediat<d\ Ih'sIc
limi'sloni'; and I herefin'e they seem to icpreseni a local modilication
of the more alaindant liorite — a moililieal ion prodni-ed hyaii increase
of lime, uhieli has ch.uiired ll ri iKnlnnnbic may;m'sian hypersthenc
to a morioclinic pyr<i.\cne.
\ rMu--iMO,iiir NUxrM
In 11
lis <'oniiectioii it mav lie well to (•(MiskIci'
the r
ormatioii ol sedl-
mcnlarii
In pl.ices i'o(d<s of maii\ \ arict ies are liidinrht tou;ellier
and iiit imately mi.xcd by the iiiechanieal act ion of at mosplieric foi'ces,
while in other places a most careful sorting: niay take pljicc; for
example. ;j:ranitic material may be separated into its more acid iind
more basic jiaris, prodiicin;; at one point sandstones and at another
shales.
.Ml I liese sedimeiitaricN. as is well know n. are olti'ii metamorphosed
iiit mplelely crystalline schists: iiid 1. in the opinion of iii.iny
able i:eolo;rists. c\ en iiiass!>e cr\stalline rocks ma\' be formed directiv
Irom t liem.
I'rof. W. S. r.avlcv ' 1
las described typical ipiartz-kera-
tophyres on I'itrcon Toint. Lake Superior, which are probably the
result of the fusion of slates and qiiai'l/.ites by intriisi\e jfabbro.
Such rocks as these certainlv can not be aceoiinled I'or b\- chemical
scirrci^al loll, and we a
re i<rnor,iiii in how Lrieal ileiirce i
iiassi\e c?'\?
talline rocks ii re thus metamorphosed fiom sedinieiit.'iries wliose male
rials ha\i' been selected by jit mospherii- forces.
I '■».
M
Tin; I'llKMiMK.SA <IK SK(.Hi;(..\Tl«iN.
The probability of cliemic.il dilVereiit iation or .se^reijat ion of molten
material beiiij: admilled in cei'lain eases, however, it wouhl seem that
'(iiililii'.... iiiiil lii.ifiii-i ..f I ni'iliiiiilt s.Ti.-,: All! .iMiir. Si'i, .luiii'. IKKH. Ilcl mTii'H. Viil. .\.\.\V,
P **"■
M)atiii. T>'xtH..nk ..ft liin.v, iili . .lili.iii. |i. :i:.'.V
*TIi4' i>ni|)livi' titii'. H«>(liiiM-ntury r<H-kH mi l'it;i><>ii I'niiit. MinnoMitii. iiiitl thi>ir ronta.'t jihi*
iiomiiia; Hull. V S. (Ii'dI. Siirvry Nc lim. Isitt
I
''^
J
GENK.SIS iiK AC.ill KUdl'S i.HIAIilV. \ KINS.
3(1'. I
in llli' I'"MI'tyillilt' dikes \M' lia\i' r\ idclii'c imiiilili;: in Midi ;ill iiii:;i|i.
Tlii'sf liiU'cs ciiiisisl of I'cick l\ |H's wliii'li all i'li:iii;:i' irriiilually ininiiiu'
Hiiiiltici', ami wliicli liavc lifcii iiilriMliici'd al siiccosix c iici'lods. So
far iis (IcIfi'iuiiK'il, Ilic carlirst iiilru.^iuiis wcrt' nicks of iidffiiii'tlial*'
ciiinixisit inn, wliili' I 111' last wcii' cvl rcnn'ly liasii- and fxti'rincly acid,
tlic acid iiilrusiiins liciim' thcxciy laicsi. .Ml ilicse mcks. \arvini,'
fl'iini I lie must acid ajilitc to l lie ninst basic inirnlilcndiie or iiyioxcnile,
are, liiiwever, esseiit ially coni|io.scd of the same minerals in dill'erent
]iro|iort ions, and these minerals ari'llioseof i;r;inite oi' tri'anudiorite.
'riie observed snccession ot' these inl riisions ajirees with Iddiiiirs's law :
wiiiie if the si'histose dikes weie o\erliioked, as they miullt lie in too
linrried oliser\ alion, the order would seem to correspond nnircwitli
that established in \or\\a.\' and (ireat liritain by UroirL'er and (ieikie,
since on l''ortyiiiile ( reek the more acid of the nnsheared dikes always
(•III the more basic, and are therefore yoiniirer. The essential result
of this is evidence that an original granitic inaf,'ina seems to have
.separated into more acid ,-ind more basic portions.
co.Nii:Mi'oii.\Ni;oi - i.si m ASK of -ii.n a .wn uatku.
In the cr.vslalli/atioii of ijineoiis rocks there is a delinite order in
the formal ion of the dill'erent minerals. .Vccordin^r to Iddin^'s,' ordi-
naril.N' the oldest mineials are the iron ores, with zircon and ajiatite,
wliicli are followed in turn by one or moit> of the ferromau'iiesiaii
silicates and the fehlspars, w itii a feldspar and (piartz as the last min-
eral to crystalli/.c. in dilVerciil rocks the order varies sli;:lilly, but
asarnlethe more basic mineral cr\slalli/.cs out lirst. The order of
succession is shown b> the rock st met lire, since the lirst-tormed min-
erals lia\(' perfect crystalline form and are often inclosed tiy the later
minerals, which are without delinite crystallo,i.'raphic bon:idaiies,
but lill interstices left ii\ those alreailv formed. Therefore, in a
mau'ina whidi is in the process of consolidation the nioic basic ele-
ments crystalli/.c out lirst, and the residual li<|uid porlioii becomes
more and more acid w illi the pinnressive .soliditicalioii of the luisic coii-
stitiieiits. If, moreover, the partial solidilication is attended by sej;-
retratioii. as seems hi;;lily probable, the oriuinal iiiai:nia becomes
separated into a solidilied basic portion and a llniil acid |)ortioii.
That basic rocks cr\stalli/.e at hi,t;lier temperal mes than acid ones is
shown by their contact phenomena. Cases of the altei^ation of the
country rock of a dike or otiier iiilriisivc body by actual heat, pro-
(iiicin;; bakintr. meltiiijr, cokini;, and I'alcinat ion, are chielly conlined
to basic rocks; thechaiiy;e is shown to a less extent by intermediate
rocks, and iiexcr b,\ acid ones, such as e;raiiite.'
.Ml rocks contain water, partly in chemical combination and partly
as inclusions, asshoun b\ microscopic study ami by eh ical anal,\-
sis. The niolteii materials, howi'ver, contain much more water than
'III, |li.'.T.vslulli/.«li..uof iuii 1-r ..li- '-ill t'l.ib,-.. S..,- WiHiiii^t v..: .\1. \< M.
■'Oi'lklo. Ti'Xt-B.>ikiif t)i'Ol.,«v.:M .■.llli. mi. pp .ViT.iUii.
^ (
,'{10 (;i:()I.i)(lV OK THE YUKON fiOl.I) DISTKICT, ALASKA.
Ilic icsiili iiiu idik: iJKisl uf iliis Wilier is ('.\|»'I1(m1 al tlif iikhih'iii df
siilidilic-alinii, In^rctlicf witli ci'i'laiii prases ami a jricat \ arifl v of iitlicr
iiiatcr'ials lii'ld in sohiiiiiii.' In the siirraci' lava this escaping' wattT
t'lnins Ilic clomis of sicani. Iiiirlilv <'harfjr<'<l willi jrascs and niincrals.
wliicli arisi' I'idmi lissurcs. \<>Mts. and I'ninardlcs; lint wlicn rocks
solidily livlow ilic snrl'aci' Ilic c\|n'ilcd waters arc forced into tlic
iiiclosinfr roi'k and liml llicir way aloiij,' \vlialc\ cr elianncis olTcr pass-
a;;c.- 'I'licsc iindciii:roiiiid waters, licinj; nndcr ^neat |iressnre and
intensely licalc<l, arc capalilc of holding' jjtrcat ipiantilics of matter' in
solnlion, wliicli material is dcrixccl from tlic majjaia from which tluy
are ;■. pelled. Therefore ijreitl cliemical alteral ion is hronjjht al>ont
in the rocks into which tlicst' waters find their way, and it is to tlicm
that most of the cll'eclsof contact mctamorphisni arc due. Thcaltera-
tion of wall rocks liy li<'at alone is. as stat(>d. conlineil to the liasic
lntrnsi\cs, and e\eii then docs not cMcikI lii'yond a /.one \aryinj; in
width from a few inches to a few feel.
INTACT I'nKNoMKN \
A< ll> Uoi Ks
i
On the other hand, contact metamorphism evidently due to jicrim'-
atinii solutions is xcry common and widespread. It is often the ease
that rock in conia<'i with intrusive liodies is altered in broad zones,
which in c\l reme I'ascs arc several miles in width. The alteral ion is
show II lpy I he rcairan^emenl and reerystalli/al ion of materials alrcaily
in the rock, ami liy I he int rod net ion of new (dements and I he a I tst lac-
t ion of old ones, so t hat the mincraloi^ical and <'hemical nat tire ol' the
ro(dv is often ciil irely cliaiiycd - limestoni's Ihm'oimc altered to clicrl.
and saiidstoiM's and shales ma\' he I ransformed into perfect ly crystal-
line schists. That this iiietamorphisin is ,iciM)mplishc<l hy solutions
is shown in nniny ways. Where the intrnsivc mass cuts rocks of dif-
t'ercnt porosity, such as jirits and shales, it has hccn noteil that tin'
more porous yrits are altered to far arcaier distances from t he iniicoiis
rock than are tin mpai'ati\<d\ impcrmealile shales, show in^ that
I he former have lieen i
iioi'c casih t ra\ crse(
1 li\ water
s iiowin;f awa\
from the coiiiiici. Till' arrani;cmcnl and succession of minerals alsi
often indicate clearly water action.
.Vmoiiiithe new minerals which are formed In these sclii-.is manx
are coniinoii which are relativeh rare In crxstalline rocdis of siiiipli
i;ri IIS oriii:in
Th
CSC minerals, such as loiiriualine and eassilcrite
point to the act ion of pises eontainin;; lliiorine and lioron, which ha\ i
escaped from the solidifying; int iiisivc rock at the same lime as tin
waters. '
' Itttiilii-ir. (Ii'ol.i^h- <-x|irriiiM-ni]ili-, I'aris. I.**;!*, p. l.V.',
'•'Ki'iiiicinili' u.i.L.ifj ..f till. MiT.ui- MliiiiiK Di^lri.t fiali slxtcnitli Ann Hipt f S (Ir..)
"(ii'ikic. Ti'.\t-Hiiiik i.f u.'Ml.iifv. :i«l I'ditli.ii. p. Ml.
Surv.'v, I'ait II. l"!!.'!. p W,
' UoM-tilm-t'li. .MiiT-i'srupifal l*h>^i<>Krapliy i.f thf lI'M-k-niakiiik' Miri.ral'-, Miliit^'.,'.. I i-ali^^lution.
■M .■iUti..n. .Ni'W York, l.^-ll. p. IM.
si'iHn.]
i.r.NK.sis u|- Ari;irKi;ors (,if\i;r/. vki\s.
311
This I'dnii 111' cdiiliM'! iiic>l,-iiiiiir|ilii>iM, iliir in |iitiiii;ii ini;- walrrs cdn-
lainilii;' wise-. Mini iiiiiicr.'ils in sdliuiuii. In I'liicHv i-cpnlliifil In llii' jifiii
I'ucks, lii'iiii:' csiicciiilly riMiuirkalilc iii'diiinl iiii niNi\ c> iii:i>m'> nt' yi-anilc.
It siM'iiis imiliiillitcilly t i-iii'. llii'i-i'l'ipi-f, lli;il till' iiiiihcii inalcii:il fiuiii
wliicli irraiiilc s(iliilirn'> c-(iiiiaiiis laiin^ walci' lliaii Ilir ha-ii- inauaia^.
. ItV-T \l.l,l/, V II. iN 1. 1 c, ISAM IK.
Tliis I'oiiclnsiiin is riiirnlKiiatcil liy ilic pioi'iii-i. in iiraiiiii- nl' imt-
liliii niiliiM'iils, siirli as iraili>liliiti', ni-l iiilr. ami allaiiilc uliidi alliT
tlicii' pliysical cliaiaclcrs al mk-Ii a >li^lil ilfi:i' il ilry lii'al llial it is
fVidcnl lliry can ihiI lia\c lii-cii rmiiH'd liy (■(iiiliiii; rnnii rn^iuii, \\liilc
it lias Im'cii |ir(i\ci| thai Ihry imild liavr I'nriiicil in Ilic |i|(-.imii-c nf
water. It is only liy sii|i|icisiiiy; that uatiT is pri'si'iit in liic'-r acid
iiiairinas, ni<>rcii\ cr. that tin' nriliT ol' ci-ystalii/al imi in ui'anilc ami
(illiiT rmdvs can lie c\|ilaili cd. Inr 1 lii^ nidci- is liy iin means dc pi 'mien t
upiin relat i\ e I'lisiliiliiy. '
I I!V-I\I.I.I/.aT|iin 111 I'Ki.MATITr.
In llie pnieess (if c| i ll'eieiit iai iiiii ( ii' setiici.'al inn. I lieiel'ore. we may
liclieve that by the pni^ressixe sepaialimi ami cnnsdlidal inn nf the
ninre liasi illslitUellls the lesidli.il pnri inn In lues prn;; li'ssi \ I'lv
imire acid and iimre ai|inMiiis. 'i'lie e\ idini-e nl' tins in the ease nf
JJfrallilc lias just been desiTilied. I'assjni; Irniii ^ramies In 1 111' next
ruid< ill the scale i>( ai'idily, pcyniatite Iwhieli. as deserihed. t're-
(lUenily Inrins a perfect Iransiiinii lieiweeii ^rraniie and ipiart/ \eiiis)
hears si rikili;;' e\ ideii f llie presence nf aliiimlani water. Tlic'se
pc^iiialites are nftcii fniiiid ill iiarrnw diUcdcts w liiidi arc pcrsisicnl
fur Iniii;- clistaiiccs, and e\ fii in isnlalcd ii'iises in the schists nf cniilaci
/.niies, thisc lenses h.i\ iiii;- iin enmmiinicat inn with t lie iri'aiiitic Imdy
which has prndiiced the melamniphisiii, allliniiuh they neciir in the
vicinity of that Imdv. In these ci-es, eNpeciall.\ in the latter case,
the material frnin which the pe;:niaiitcs wen- fnrmed iiiiist lia\e liecii
L;rcath alteiinatcd in nlcier In lra\ersc the scjiists in the aliseiiec nf
well-deli I lisslires and liiiall> In depnsit the pe-iiiatile ill favnralilc
(ipi'llinns. ,\tlelinal inn nf the llllid which has prndlWeil pe;;inatitc is
also slinwii by Iheeslrcine frcednm nf eirciilat inn wliich must have
prc\ ailed In permit it\ sialli/al inn nn s,, la r.^e a scale as we liml it,
fnr ber\ls a sard in diameter and spndiiimMies and feldspars nver :iii
feet ill leli;;tll lia\ e ill e\liel ases I n prndiiced. Man\ n{' the
peculiar minerals charai'terist ic »( the /niies nf emit act melamnrpliisiii
ill the vicinity nf manite are also fniiiid abiindanl l.\ in peumai ites.
such as tniirmaline. lev> fre.pn>iil ly c,is>iierile. ,iiid niaii.x mlierrare
minerals.
'liclkl.-. Test RiKil( of ( hvv M .•.llli.ni. r- ■»"
■'li II Wiiiiuni-, i'iit..'iitii .\Mii i(.|.t. r s diM,' siii-\.A i-ii."i p ii;i>.
= Croslj} uii.l Fiillii- .\iii i|.'nl..Ki-.t .Miirih. IMiI. p i-il
?
o
II
■i '
1 -'*
J i .;
I'^^j
W '
. 't
«n
;Ul' (ii;ui,oiiv OK Tin: vikon cki.d disi'kh t. alaska.
iiniN 111' 1 i:ui.\iN sHAur/. \ i:ins
iiialh . I III' iic'^iiijil II H' I'lM-
i\ till' ili>ii|i|ic,ii;iiicr III' I'cliisiiMi- .iliil
liiu-a. iriMi
into |iurf iiiiailz vriiis wliicli s
llllW
II
liMP St I'licl lire
(siller tlicy iiciicl rail' In ilif iiiii>t iiiiiiiitc crcx ices and ('.\hil)it I'rc-
iiuclit hainliii;,' anil cniiili sti'iii'l lire) llial tlu'V lia\i' 1 n (1c|)(isilcil
from soliiliiiiis mi attciiiialril llial llicy may Im'nI Im' (icscrilit'd as
waters liiylily liealed and heavily eliai-;red willi mineral mailer in
soiiiliitn.
'{"iierefiii'c a emn|ilele series of nicks lil»(> tlial wiiicii we liave on
Kurlyniile ( reek, ranirin;; frniii iillraliasie rucks, eimsisl inj; cssenlially
of inelallie and rerroma;;nesian minerals, In pure (|iiarl/ \eins, may
!)(' conceived to liave formed li\' a iirocess of dill'erent 'al ion or seiirp-
a
ifat ion, tlie cr\stallizali'.
llie basic |ioi'lliins lca\in;;' tile residne
snccessi\el\ iiioiH siliceous and more ai|iieons, mil 11 al I lii' liiial stai^c
lliis residiK' is lil'le moretliaii hot siliceous waler, wliicii contains,
liesides silica, small c|iianlilies of many other rock elemeiils wiiich
haxe iioi lieeii lake i u|i liy the rock-forniinii: minerals.
s(iiH( :■. i)V (idi.j) IN i.nAin/. \i:iNs.
liiii.n IN loM-.ois liocKs.
This boinjr considcri'd llic orifiin of ([narl/ veins (siicli as tliose of
the l'"orlymile district) \xliieh have evident connection witli ;;ranitie
or otiicr iuneo'is hollies, we may next iminii'e into tlic source of the
tfold which l]ie.\ contain. Tlial ;told and other minei'als found in tlie
veins are jn'csent very comnioiily, thonirh in small i|nantities, in ij;ne-
ons rocks, esiiecially in dark-coloreil silicates, sncli as liioiiie, hom-
lilende, and olivine, has lieeii shown liy tlie chemical resear<-h of
."^anillierjicr. ' Mr. S. !•". iMnnions- has directed a seriesof careful lesls
of selected iffncons rocks from dilTeieiit localities in Cnster Connty,
Colorado, with a \ iew to determining^ their melalli inlcnis. Fixe
onl of the nine rocks tested contained a|ipreeiatile ainonnis of sil\(>r,
and In one of these liotli siherand lead were fonnd in eomhinalioii
wil li ol her liases in the I li silicates. These rocks wei'e ti'achvh
ilio-ile
rlivolite, and ililTerent \ ariet ies of ''ranile from dilVereiil iocalilie;
I'rof. (;. 1'. .Merrill' has deseiihed an
occurrence o
f fi'
ee i;old in
jiranile, whicii he jiid;;es to lie orininal. The ,u:old occurs associated
with th
a or wholly emlieddeil in the crystals of (|iiai'tz or feld
spar. I'rofessor .Merrill also notes thai W. Moricke has descrilied
free iii)U\. which he repir'ded as an oriy;inal constitnenl, in a niuwi/,-
trai'li.vle from ( liile.'
' rntt'r-turlmntffn UImt Er/.j;llii^ft'. IH-s:,*.
■'S.'Vi'iitiviitli Ami Hi'pi r S (Ji'ipI Survey. Pint II. iHim. p. am.
».\Mi, .lour. S,'i . .\pi-il, IHiiii, nil «,.ri,.H. Vol. I. p. ;iiili.
< W Miii'i.'lio. Twlifnimks ihjn.'iiil .Mittli.'il . III. \XVL
•ii
II
■^
MTHir]
(iKNESis uK Ari!ii-i;ii(irs (,>i akiz \i;ins.
3i;{
.MlNKKAl.iH.lcM, lli:i.MMN~ ..|' ITi.M \TrnS AMi i,.|.\|ll/ \1;|N, |.. l.jSKulS
Itnc Ks l\ OKM-.H \].,
Ill |)fi,'iiiiil ili'> .-iri' t'diiiiil iiM iiiiiisiiiil iiiiiiilici- 111' rail' Mini wcll-
(•r_\ st.-illi/cil iiiinciaU. In'sidi-s ilii' (•ciiiiiiicnicr ^|)l■(•i(•^. A >iii(l\ df
llicsi" iiiiiMTals sIkiws llial llii' lliiiil Irmii wliicli |ifLrinal ili' lias roiisoli-
(liilfil iMiiiiainc<l iiiDsi 1)1' the i-lciiwiiis lliat ciiIit iiiln ili iii|(iisi-
tioii 111' rcii'Us. 'I'liis lliiid, hiiwcx IT. a> IpcI'chi' slah'il, iiiiisl lia\i' lircii
j;rcall\ allciiiialcil, ami In I liis allciiiial inn llir M-jriciral ion nj' widely
(lilVcrcnl iiiiiii'ials in (iill'ii-riil pails nl' llic |iciriiiiilic lioily may In-
ascrilird, for ii has |M'iiiiilicd aliiiiidant ciiciilai ion. and llicii'hy pro-
motcil llii' conci'iii lal ion of nnUiTials orij;inall,\' dissciiiiiiaicd in
iiiiniitt' (piaiitilics I liioii^lioiit.
Passing I'roiii |M'i,niial ilcs ioi|iiail/. \«'iiis. \\f liml ihai alllionijli ijio
ntiici' iiiiiicrals Im'ciihic i;iTatl.\ siihoiiliiialc in i|uaiilil.\' lo (piarlz, .\<'t
of tiiosi- wliicli do occur llicrc is an c\i raordiiiar.\' variety. iU'iii'y
Louis'- lias compiled a lisl of no fewer iliaii 77 mineral species, inau.v
of tlu'lii rare, occiirriiii;- in auriferous i|iiailz \eiiis. .Mr. (J. K.
Meeker ' has made oiil a lisl of lii' iiiiiieials which occur in llie aurifei'-
ons (piai't/ \ eiiisof llie soiiihern .Vppalaciiians. 'I'liese spei-ies include
loiM'maline, cassiterile, lliiorile. and other minerals which are rare,
and which are also ehaiaeterisi ic of pei^inalile and of the eonlaci
/.ones around acid ill! i'usi\e 1 ks. it is found also that nuiscovite,
liiotile. and ori hoidase occur occasionally as (laii of tiie iraiifriu' of
<;ol(l-<tuarl/ veins, and tliis seems to establish a further link hetwciMi
auriferous <|uarl/ and pc^rinatite.
( oinparinjj; all the minerals found in peirmalite wiili those in (|uai't/.
\ eins, it appi'ais that iiearlv all I he elements present in I he II ii id from
which iie^'inalile is formed are also present in ihat prodiicinn- (|iiart/.
veins, .\moiin' these elemeiils arc nearl.v all the metals — for example,
silvtT. <'iipper, l"ad, liii. liismiilh, iron. maiiLranese, arsenic, iiiolyh-
dcnite, /.iiic, lelliirium, vanadium, I un.nstcn, eic. As ordinary metallic
(•onstitnents of <|iiai'l/ veins. Louis' eiiiimerates iron pyi-ites, ^alciui,
copper pyrites, tiliiiiiferoiis iron ore, arsenical pyrites. /.iiic-l)l('udc,
slilmile, and mai.'nciiie. .Mr. (i. !'. Ilccker,"' in spcakinifof thei^old
ores of the soul hern .\ppalachians. makes I lie following; si at emeu I :
The ,i,'i)M iiri's (if till' Siiiitli ariM|iiiu'tzii-e ilcpusits with very sulmrihiiiiti' ailiiii.x-
turesof I luliiinati's in wliiili [ivriti' i-^ always jireseiit. while liiiili'npvriti' is com-
iiiiiii. anil Ltaloiiii. iiiispirkel, ami ziiir-lilnuli' are lij iiu means rare. The Imiw li-^t
iif the ollur iiiini'ials funinl in the veins is uniiiiiiortaiit. exei'iitin;; in so fur as it
assists ill I'luciilatiii^' Ilie f;eiiesis iit the ores. I iim iiiialiU" tn see that llie iiii'oiii-
IHiii.viiiK inini'iiils. with the one cveeiitimi nf ii.vrile. serve in any way as an inili-
Oitiiili 111 the value ur e.xlenl nf the me hollies.
Ml. II. WilliuiiiM, Flfti'iMitli .\nn If. lit. r. s ()i..il. Survey. ]>. ilT.'i. ('ri»ili>- iiiid FuUi'r. Am.
(J.M,l,,t;i>t. v.. I. XI.V.N'ii :i, p l.vi.
■'MiiiiTiilnijiial .Mii«., Xiiv.. IKltl. 11 :Jll
'Sixti'i'lilh .Villi Ki'pt. L'. S. liv.il. Siiivi'). Part III. tv.i.-i.ip. r.i.
>i ip. lit . p -'Hi
•lip I'lt., p. •»!.
\%
ii-
-f
r
L'tii
;'.14
(jr.Ol.odV OK TlIK YUKON <iOl.l> DISTRICT, ALASKA.
m
III tin- AlilNlviiii veins no opiiort unit ifs l<ir cmi'i'I'iiI ii1)sci'\;i1 inn of
},'aiif;m' iiiiilfpials on a larjrc scale were olTered. luit .some of the iiiomI,
iiii|iorlaiit minerals, siieh as jralena. pyrile, elial(o|)yiile, niairneiite,
liarite, oaleitc, etc., woi'o no(etl as oeeiirriii};; ami i( seems prolialile
lliey are like (r.iart/ \eiiis in other parts of the worlil.
\l.\NM:ii <>l' ( ONCKNI'liA rio\ (iK <;iiiJ>.
In <|iiarl/. veins as a whole, therefore, we appear to have, lioides
siliea, most other elements in small c[iiaiilities, ineliidinu ^rohl. It has
already lieeii siijijrested that the Alaskan veins, wliieliare so intimately
eonneeteil with aeid ilit riisi\e rocks, have lieeii deposited from the
residual lliiiil left hy the crystallization of these rocks. We may there-
for iieei\e that the water expelled from the <'ryslalli/iii<,' jrranite or
a pi it e eontaineij cli icily silica, and also jrold and many othi'r eli'iiieiits,
in solution. .Ml those eleiiieiits were prolialily \'ery nnil'oriiily ami
miniitcdy disseminated ill t he residual lliiid, as they are in the iniieons
ro<'ks. W.iter discharged from coolintc rocks is hi;;hly lieateil.ami in
these jiranites ami aplites, which liave soliditied at a consideralde
deptli lielow tile surface, the e.\|ielled waters must also ha\e heeil
under fjireat. pressure, so thai, the solvent power was vastly increased,
allhou^di the circulation was not f,'reatly impeded ihereliy.
This residual Iliiid is prob.-ihly of a chemical idiaracter especially
Well suited for lioldin;; ;;ol<l in solution: yet it is not. necessary to
suppose that the metal is |ire.seiit in i|iiaiitily relati\c'ly mindi ;,'rcater
than in ifiiieous roidis. It is to he rememlicrcd t hat , were t hi' i;oh I dis-
seminated ill iirneoiis rocks eoiiccnl rated, weshoiilil lia\ e in places rich
(leiiosils. In t he |iroce.ss of solidilic.it ion of t hese rocks, however. I he
materials are proliahly much less fluid than those from which <|iiarl/,
veins are formed. Therefore circiihit ion is slit;lit, t li- rystals formed
are small, the rock is coiiiiiarat ixely uniform, and th „'old ami other
metals, not haxiii^' opiiort unity to se;rre};ale, are jjeiierally dissemi-
iiated throuiihout. As the iiiaLtma liecomcs more lluid. however, cir-
culation lieconies greater, crystals j;row to trreater si/.e, ,'iiid the
metallic elements are permitted to seirrej,'ate. It is well known that
(piartz veins are pockety — that is, are in places rich in pdd and in
other i»laccs barren, and that in the same dislrici some veins cany
j;old while others do not carry .•ipjirecialde i|uaiitities,
M.\.V.\i:i{ Id" siit.fllON A.NIi l'l!i;(ll'll'.\llu\ ol-' (in|.t>.
(iold is soliilile ill many of the ciaiimoncr salts;' and it has hceii
[loinled out liy \arioiis writers that silica and ^old may often pass
into these solutions and he deposited from them under the same con-
ditions.^ In the preoipitalioii of the pdd it is prolialile thai pyrite
'Frc'iiiy. i;niyilojuiliiMliiiii|(|iii', Tiiino III, III'' culiiir. |p i:i
■' Itr. (i. K. Hi'cki T. Si.xti-i'iilli .\iin. Hfpt I'. S. (ir.il Survfj. I'lirt IN. IMri.p :;.•,»< Dr T I".
Egli'Hton. Trull". Am Ins. Min. liiiK . Vol. l.\. p liWutsfii.
V
GENESIS (IF AlKllEliOrS (.if AKT/ \ KINS.
31.-)
and olli.'i' siilpliiiics jili'i'iidy funned ;iic iiM|)ciil;ini ImcIuis. < M' all
till' iiK'tidiic iiiiiiciiils with wjiicli jrnld is associated in i|iiai'tz veins,
iron ii\ rile is most alinndanl, and ils presenee seems td he in a liiiilled
way indicat i\ e ol' the lieluiess of liie \ clii. Mie;nse(i]iie exainiiial idiis
of tins pyrile j^eiierally show iiielallie jrold, which has been deposited
sometimes tiiion th(> pyrites, sometimes simnltaneonsly with it; aiLil
in the laboratoi'y it. lias been shown that pyi'ile is ono of the best pre-
eipitants of jjold from solution. Often, howevei-, the ityi'ite of ipiai'tz
veins is not iissoeiafetl wilji jjold, and. on the other hand, ^old fre-
(jnently oemirs isolatecl in the (pnirtz ami is |)ure, except foi' conlain-
int; small proportions of sihcr and ot her metals. In this latter case
the Jiold must have been precipitatetl l)y other moans, proliably often
.simply by elianjre of temperature oi' pressure. ^
()i'.si;i£\ I'.ii ((i.\NK( I i(is di' (.(ii,ii-(,ir AUt/. \i;iss w i di i\ii;i -^ixk
micKs.
Tile conneelion of auriferous quart/ \ ejus with intrusive iniieous
rocks, especially diorite and frraiiile, has loiifj lieeii known. In Aus-
tralia tile ;;old-(piart/. veins, in cerlaiii localities at least, ociMir ;it the
contael of diorite ami schists, and in I he I'rals the preseii )!' u:old
depends ii[)on llu currence of eru|)tive rocks and tectonic <lisliirb-
anees.' I'rof. .1. D. Whitney- noteslhat in California. while thei;ranite
itself is not. melallifei'oiis, itsapjiearaiu'c seems to i)e closelx associated
witli the metamorphism of the adjacent sedi niary rocks, wliile this
latter condition is, as a j;eiieral I'lile, the ccuiconiitant of theoecur-
i-onee of minerals <u' metalliferous xcins. On the i'clly |{i\er in
]>ritisli Columbia, on a jiarl of the ^■ukon jjold belt. Dr. (i. M. D.iusoii '
found evidence to show lliat the developm(<iit of ipiait/, \eins had
occurred <'ontemi)oran<'ously with the upheaval of the ijranites, and
probably by some action su|perinduced by the irraiiil<' masses theiu-
si'lves while still in a format i\t' condition. .Ml the obscrv alions made
in lh<' Yukon ;;i)ld district by the rniled States Oeoloirical Suiv.'y
jiarty under the cliar,i;e of the present writer jioiiit to the same con-
clusion, and these observations ha\c .-ib'eady been fully de, ailed,
SlM.MAIiV.
A theory of the ^'(Miesis of auriferous ipiartz \eins may theiefore be
sU;iimarized as follows:
.\ molten maj;iiia may become seirre.aaled or <lil1'erenl iated inti^ ilis-
tinet porti(Uis by the successive |)recipilaliou of basi<' and thi' excre-
tion of acid iiorlioiis. With incieasin,i: amount of silica in the residue
llier(> is also an iiiereasini; proportion of water over other materials,
this water beinj,' ill all eases ill a liifrli state of union witli the other
' K. vim Krmitz, Am. (IiMil.i^lst, Vol. XVIII. Xi>. :.'. p. 1"T
•' A\irifc.r..u» (ii-iiv.'U of th.' Si.-i-ni Xi'viiilii, ii ;l.Vl
".Villi, liopt. Uu.il. Milt. Hist Sm-vi'.v I'linuilH. V.il. III. part I. \i ;l"iB
Hi'.
V ■ if
& M'
Mid (iKul.OOY OK THE YUKON (iOl.l) DISTIUCT, ALASKA.
iiiatfrials.so Imifi as tlicsc mate rials ai'i' iinsolidilii'il ; lli is slate of nil ion
may lio I'lthcr clK'niical or iiliysical. In lln' liiial rcsiihn- tin' (liiid
bfciniit's su ai|iii'niis anil s(i siliccinis I hat it passes with im sharp (li vi-
sion line into lii^rlily heateil, siliceous waters, which contain also small
ainuiiiitsor niosi of the other rock-t'<irmin;; elements, and amoii;; lliom
'.'old. (jolil occurs in the iuneoiis rocks, lint is iiniroriiily dissemi-
nated, since it has no opporliinity (o seure^'ale on a<'coiiiit of the
relatively sU;,'hl lliiidity of these rocks <liiriii,i,' the process of solidili-
eation. In the (iiial hiji'hiy siliceous and hi>;hly a(|iieons residue,
Iiowover, the fluid hccoiiies so attenuated that circulation liecomcs
very free, and concentration of the rarer elements is periiiitlcd; so
the jjold is .sej^re^rated, often into pockets of considerable si/e; and in
a like manner other materials are concentrated, generally i dependent
of the concenlration of the ;;i)ld. It isalso prolialile that i ne residual
solution is, owiiijr to jiliysical or chemii-al conditions, or Itotli, especi-
ally adapted to the retention of ji'old, and tliprefore is relatively
rii'her in this metal than ordinary nietallifc rons solutions, and possi-
bly more so than the molten iiiai,'nias out of which the igneous rocks
solidilied.
This theory is not intended lo apply to the occurreiii'o of gold in
any other form than in the typical gokl-qiiarlz veins.
liJii
iii
•1
,'i*'^
-m
M
'Ill
b
mi
/'
C-
*»V1,
INTER NAT 10 NALVjv=t,
r boundary'
^^
II'
■^Ji^
BR_ITJI_SH_AM ERICA
ALASKA
00
<
w
«
o
o
o
Hi
■I
,
r II A I' IK I! \l
1M,\< I.I! i>i:i'o>ri>.
'i'liroiiirlKiiil iK'iii'ly tlif wjiolc oi' Ai!t>k,i i^'ulil is fmmii dissonil-
llillci ill Itll* (li'tlilllS wllicli li;is lii'i'll ilriiM'il ficilll the il lilM-'ii HM it'
llic solid rucks, oi'li'ii it is in siicli miiiiII iiimniiii tliiil it imii ikpI lie
Iti'ofitiiltly cxli'ai'tcil, 1ml sinndiiiH's it is ciincciiir.iii'il |p\ umIit Mdinii
ill sucli (li'}j;r(
iis 111 in\ itc iiiiiiiiii;. 'I'lius Till- till' |iiiiliinlilt' ili'|Hi'-i
liiiM' all liccn I'cimiil in or niar llii' linis of the pirsi'iil >lriMiii>
'I'iu'sc iccrMi ;. ;avfls
iiia\' lie ili\ idcil into two rliicl' I'li
In till'
larj^cr streams aciMiinulatioiis of ;rra\i'l are niaili' in |)lari'>. ot' slai'k-
riiiiiii I'urri'iil, sncli as tlii' iiiin-r or coiirav i' siili'sul' imum's. 'riii>-r
ai'ciiniM
latioi
IS art' ca
lli'il
Mill ol'ti'ii I'liiilain niMi'li irolil.
■I'll.
oilier oeeiirrei.ee is in tin small siiilelies wliieli I'eeil I lie la rvrer st reams
In the holloni of l liese
ill IColil, anil as 1 liese ar
llie gravels are lrei|iienllv ver> rieh
re easil\ worUeil, tlie\ eonstilnteal llie jiresenl
li '
time the most importaiil elass ol plaeer ileiiosii
GULCH DIGGINGS.
hiiUTVMII.K IHVllllt T.
The Fortyniile jilaeer minii
lisiriet iiielinles sonii
''llll'lles wliieli
lllo Sixtviiiile Creek, sueli a-
.Mi
ler ami
run into Fortymile Creek, ami s wliieli run into SiMymile (reek.
Throufih lliis (lisiriet the inteiii.itional lioundjiry runs, dividiiiy: it so
tlial the fiiilehes uhieh How ii
(ilaeier, are in I'.ritisli territory, while the iifeater part of the ilistriet
is Anicriean. I'l. \\.\ is .-i ma|) of I'mlymile Creek and vieinilyso
far as is known. This map is from skelehes iiuide by the (Jeolo^neal
Siirv<'y party iiiider the direetimi of the writer, with the exeepiion of
that |iortion i
hoiiiidary am
if Fortyniile Creek whiell lies helweeli the inleriialioiia
I the Yukon, whieh is taken from a survey by the I'liiied
veil, is indi-
StatesCoast Survey. The topo^n-aphy. so I'aras wasohsei
caled on this map hy contours at intervals of ."ii'" feel. The position
of this district in relation to the rest of the Viiknii pild hell is iiidi-
1 on tilt' p-neral mapof the <ioU\ belt, where the area occupied by
•ate<
the Fortyniile map is shown by broken lines.
IHSCoVIKV.
lid was discovered on the bars of Fortyniile
lamed Franklin, and this wasquii kly followed
I ill the diirereiit jjulelies. .\ full. 'r account of
tile discovery and sub.seiiuenl history is civeii in .i i.rcvioiis chaiiter.
ol t
III the fall of iMSi; -ri
Creek by a prospeelor i
hv tlie Undiii}; of jrol
.•.- 1
:',\s (ii.i'".N (II .111-: m'kipn cm.i' di-iimi r. \i.\»ka.
HI i-i:." K '.Ki'l ■i■.^ .
I'll.- li.'d ii..k i.'.M,lu-\ .it' ill.- I'..,iv null' 'l.'iiii'i i» .l.-fiilM-.l III ilii-
.■liiijii-'i- ..II ill.' :.'im.1.i'_'i.mI .■.iliiiMii. mill will I'.' li.'i iil\ liri.'tiv -11111-
liiari/<"l
III.- ;_'cii.Tiil -ifti.Miii'.' i> 'lull ..r all .'M-i «.--i I r.Mi.iliiLr am i.-liiii'.
till' a\iN I.I wliii-li - ill ;.'i'ii.ial |iaiallil 1.. I lit' main I ii'ImI ..I' I-.. it \ 111 lii-
( I'lM'k, iiinl at mil' | la.i' 1 in.- almii,' lln' >li\ iili' Ih-Ivm'i'Ii t Ih' >i \t \ in lie
mimI I'liil \ iiiin' watri - M.'i.L' t III- a\i- i- i'\|iiimm| a liasal -rlii^lu-t'
Uiaiiiti . airi .>ii III"' 'I.iaU- "I tli.' t'.il.l ai.' i|nali.'lti'--i-liisl- lii'lniiLrinir
In tin- lliii'li (ii'i'i. -1 lii'-; ami ah'iM- iIum'. inaiMi'. i| ilarl/iti' -.-lii-l -,
itliil III. in- liit;lil.\ iiii'l ■•ni.>i|>li>i-i'il Inn iilili'inli' ami iiii<a--i'lii>l-. "Iiii '1
ail' .alli-'i till' l''i>rl vinili' >.'i I.-- In iln'-i' inrk- aii- ilik.'- nl' all kiniU,
Miini-l iiiir- In •_''ii'at aldin.lan.'.-. .'-lii'iMallN ..n 1 In- >.nii h I'.iiU ..t' I''.i|-1 \ •
mill' Ci'ii'U I tii till' ii|i|ii'f pari ..f tl..' Sinilji {''ml,, in tin' \ ii'inilv nf
iliii'ki'ii ami Na|»>li'i>ii riirk-. ai >' Lrici'ii tiilYsaml slates lii'luiiLrilif^ l<i
il'" l{atii|iail si'i'ii's. All ilii'-i' ii.i'k- an' iim'unriirmalilv .i\ I'llaiii nil
( liii'kcii ami Na|inli'.«n I'lirk- l.v tin' •niiirlnini'iati'. -aml-tniii'. ami
'•..al\ -liali'-..r 111.' Missinii < I'l-.'k -I'lii's. i''inall\ . nil llii'-anii' twii
I'll I'k- tlii'ii' ni'i'iii' lai'L'i' |ialrlii's lit' Ti'il iar\ lia-all . Tlir iiiu-l ma' ki'il
iiicak in this si-rii's is thai -1 'pa rat iiiLr tlic Mi—inii < i-.m'U .•...ii'lnii I'latc
I'lniii llii' iiiali'rl\ iiiL' l'aiii|ia(t ami j-'nil \ lail.- i.i.'k-
I'lnl II tin- I-'. ..'t \ ;<iili' ami I ai' liircli < ii'i'k -I'l ir- an- (ill "il « il li ipiail/.
\i'lli- liiaiiv .'l'«llii'-i 111' alinl'i'lnll-. 'Illi'si' \ rilis I'lirilish jrolil Intlll'
-I ri'aiii '^'lax I'is.
.,) I.I .11.11 \ 1 M * l'»
A M'ly riiiiirli i.-i'nlii_..'al map I'lnlinilyiiii.' tin' ii'-iilt- nlilaiii.'.l in the
I'lirt \ mill ili-trji'l lia- lieen piepareil. ami lia- lieeii i||\ i.le.l intntwn
.sliei'is (Ms. \l.\ I. \I,\'II. the rnrnier ill pniki'l I. Tlii' areas ii'pre-
M'lii.il :: till -e sheets are imliealed li\ Innkeli lines nil llie yelierill
llllip nf tl: ' ''nil \ mile ilisl rii't .
>"liel I re il'esellts the ;;eiiliiir\ In the re;;iiill nf .Miller, 'ihieil'l".
i'lik.'l . ami ' »a\ is ei-eeks, 1 he l''iil 1. Villi le-Si My 1 ' le lii viile. amlapnl'-
I'nn ..I' llie mam r.irlyniile < I'ei k. < Iii llii- inip the y;ii|eli ;ri'avels
aiel il,.' I'l I'l- !:ra\ .1- are .list iir_'iiislii'i| 1>\ -eparate eulnrs. The ;;iileh
•_ia\i'i- ar.' eniil iiiii..;;-. I'.ir lhe,\ are ilireelly inaile up .il' tain- t'riiiii
thesliep sinpes. wliieli the sinali supply nl water ill the j^lllelie- is
illsllHieiellt tnreinnxe. They are eVel'N where preselM. Ill the lliaill
e'eek. I'liWeMr, ale la I'L,'!' sll ppl i"- nf » a 1 1 r. Ill lliall.\ plaee- -llfticiellt
III keep t he I'lianiie' I'lee rrnlii aei'llllll'j.ll lulls, ami niil> ill reiiinlisuf
slaek eiirreiit ill. . i\i'l aeeiiniiilai ill's. Ill' liar-, i'min. rherernre mi
the map the ri\ei';.'i'a\ el.s aie li:'-|ill\ represeiileil a- lieiii^ intermit telil .
Ill this map the ;jraiiitii' avis nf ilie I'nrt \ mile ant ieliiie is stiii«ii.
I anki'il nil linl h -Lies ll\ I he Hi nil ( leek >.illi-ls. « hieh are sill 'I'vei led
nlhe iinrthaml In the smith l>\ the I ks 111 the l''iirtyniile .series.
'n the i|..rill\\i'stci 11 part <>( the map Ireiplellt dikes are seen ellllin^t
l.ie sehisls 'I'liese dik'- ale nf .1 '.^nal Nam t\ nf riiek. as already
■J I
Kt^
47
•
r. n
7.
— /
1^ < i
V.
^'5
,-H
<
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X
■■N2
s
t
ui
<
o
4
U
1 ■*■
' 4
y
I z:
' o
o
tij
'A
jiri f!
(in (II M(i(;i.Ni,*: riiKMMIII MSIKIil.
3l'.t
I'llllv (ll'MTilMMl. lull llli- iJill'iTilll l\|i
L:i'ii<liiall\ lliiii it liii<> liiM'ii ihiiiiclii lii'-i I
.iii:;>- nil.. ..ii.. .111..1 her
ml I<i Ml li'iii|it ,iii\ i'':i»>>ilii-ii
liiili. 'I'll.. ililVi.H'iil ii^c- .if llii' iliki-s. liiiwi'vi':. :iii.| till' nialilD'l' ill
\N liirli llii'\ i-iil .1111- ,111. illi.-i. .Ill- iiiilic'.ili.l li\ lii.'ir .'HI liii..N
SllCCl J ll'|l|l.S|-||
I- .III aiiM 1\ in:: jii-i vm'^i ..i ili.n -Iniuii .m shfct
l.,iiicl iiiiii|iii^i.> I'oi'l \ mill- 1 11... k ,il"\i. (•'Kiicii ( ic. k. till- >ciiii|i
h'nrk III' l-'iiil,\ iiiilf, Miiil I'lMiikiiii .'iiiil ,\ii|Mi|iuii .iiik", uiili tl,,
lii'iiil III' ( liii-ki.|i t ii-.'k I'll llii» »liiil ilii. L'ulili .iiiil
lllil 11 \ IT 'JWiK I
lllr illilii'illi'il .1* nil .-I I I !ll I his i-i'iriiiN tin "i-.l|.||\ |iil<'li Ml' l||i.
I'lill \ mill' iiMl il'iilli. IliC a|l|).lll'lll 1\ I'Mllll'il I 111. :;l;|llil|. |.\|iii-.|.|| lull Ili'T
II' siitr.ii'i.. il> |ih Iii'ili;;
»l aliiin: till' axis 111' ihis I'nlil Ih'Mi'miIi iI
laki'ii liN llii' lliii'li t ii'i'k >i'lii>l>
.'iinl III I III' ii.ii'ili ,iimI 111 til
nitli
(>( till' liiii'li ( ii'i'k •.I'lii^l-. lie I III. nii'ks .il till' I'liitx :iiili' '.I'lii'N I'll
|\l> 111' till' I'lllll ,'lt llli- iMlilll,
liiAM'M'i. i- iii'i'U|iii'ii li\ a i;ii'at |ir
I'li-imi III' iliki's. Miiiit' 111' iinniriiM' -i/i'. ami llii'-r liavi- •<ii altiTi'il iiml
ili-tiiili'il till' iiii'k- wliii'li llii'N I'lil liiat tlii'ir >1iiiil iiii'. ainl i'\i'ii
Ilit'ii' 11a I nil', i- II. It al«a> N iiilaiii l.iki' I In' .liki'- -Imu ii mi >lii'i't I ,
IIh'm- ari. Ill' all \ aiii'l ii'>, I'liuii i'\l ri'iiii'l\ .iriil t.. I'Mii'iii •!) Iia-ii'i >i'l
lirrt'. alsii. mi I'l.i— ijliral inn lia- Im'cii ,illi.iii|ili'i|. -a'l i' that ;;i\i'M in tin'
el la I it I 'I' nil iitiii'iiiis I'm- ks, ami t lirv lia\ i' lii'i'ii iiia|i|ii'il nmli'r mi ilm.
IIh' ijid'lTI'l
Ill ayi'
ln'in.' ■.Iiiiuii li\ lliiii' iiiilliiii". I Ml ( liii'ki'ii
Cn-ck, ami mi I'mlymiii' ( ii'i'k .iIimM' i'riinklin <iiilili. lln- I'm I \ iiiili'
nicks .III' iivi'i'iain li\ I lie irti'i"! sli.'ili-. .iml I iilT~ nl' lln- liaiii|iai'l si'iii's,
ami 1 ' Il till- l{aiii|ia!l .iml tin' I'mlvinili' im-ks aii' nM'ilain iiiit'iii
t'linii.ii.lN mi Na|iiili'mi ami < liirki'ii I'li-rks \i\ 1 1 iiii.'lmMi'i'.iti's. s.iinl
sliilio. ami I'lialv >li.'ili's nl' tin' Ml'^simi ( ii'ck si'i'ii'N. I'iii;ill\ |iali'lii's
111' Ti'il iar> liasalt .in' I'miiiil mi Na|iiili'nn ami < liii-kfii i-ii'i'k- .iml an'
i'i'|in'>i'iiti'il nil I 111' ina|i.
.\i'«'iiin|iaiiniii; iIh'-i' Iwn l'i'hIii'-Mi'.iI 111.111- aii' rmiLili ii.is- -iTiimi-
I'lUisI nii'Ifd .111 an i'\ai;y:i'i'ali'ii vitIh a! m'.iIi'. .iihI inti'iiiliil in iniivi'V
an iilca nl' llii' L'l'in'i'al -t iiii't nn'. alllmiiLili nn |iii.|i.nsimis In ai'i'iliafv
111' ili'lail ail' iiiaili'. In tin' i-ni— -I'll imi ai'i'iiiii|ian\ inu -In-i'l I tin-
l''iirt \ mill' aniii'liiii' iv -linvvii. .111
■aMilll.ll illkl's. .■Ilttiim till' M'lli-
loM- I'lirks. Ill till' M'i.|inii acriiliilian.N inj; slii'i't J I hi' -.iiiii' aiil ii'liiK'
is sct'ii, lull till- iiii'ks aliiliy: ilN axi-^ an' niili'h ili-lmtril li\ lln'i^rn-at
aliuml.iiiii' 111' ii;iii'mi> intin-imis \i tin. Ii'li nl' tin' -.•ciimi lln'
ltaiii|iai't M'i'ir- ami iIh' niiinnrnfitialilx .i\ i'il\ iiil; Mi-— mn < icrk
si.|ii"> ail' n'|ii'<'M'iili.i|
ni -. iiii'i |. .\ . .1 ..I I . ill -.
Till' ilitl'i'ii'iit -nlihi's III till' Inilyniili' ijisliiil whiih lia\i' |ini
(lili'i'ii plai'iT ynlil ill inilalili' aiiiniinl «ill im" lir iji'si'iilii'il in ili'lail
(HI hi'-c i|rsi.|'i|il i.i|i> I III' ii'|iiil I- nil Milli'l- .'llnl ( hii'ki'll rli'i'ks an- li,\
I'liki'i', l>a\ Is. .inil I'f.inklin mi.i'ks li\ II W
,1. K. Spiiir; lliiiM'
(niiiiliirli ; ami llinsi .III (ll.ii'ii'i ami N.-iiinlinii in
•Scliiaili'i.
■ks liv 1 (
!«"
ijj
2i> (ii;(»i.()(iY di' Till-; viisON (;<>i.i) i)|>iui(:t, Alaska.
MrM.>:H • iir.r.K
.MIIlf|-( I U llils |il'i>l);illly Im'I'II till- llliisl |)lil<lllcl i\ !■ dl' I lie ir||lc|||.s
ill I 111' I'nil Villi !<• ili>.I lirl. ;iiii| lie* ill I 111' iiiiiiKMliatc \ iriiiil y iif ni Iht
triililio uliicli liii\r lifcii iiiiliilily inipiliH't Im', siicIi as (ilacicr, I'likcr,
lliPW illlii
!• pail 111'
il I);i
•ii'i-ks. Till' uali'i's 111' MilliT aini (ilariiT I'liM'k
■M'avalril llii-ir ili'r|i \ allry-. ill lali'
Si\l\iiiili' C'ri'i'k. uliili' lliusripf I'likiT ami l)a\ is itim-Us ai
llic lirailwali'is 111' i'liityiiiilf ( rcrk. 'I'lu' iliaiiiatri' areas nl' Sj\l \ mili'
aiiil i'mlyiiiili' iTi'i'ks an« si'pai'alcd liy a liil^rc of iiunlrralt' JH'ijrlii.
wliiiM' tii|i is i-iiiiiparativi'ly llat ami I'liriiis part nl' tin- u'l'Mrral plali'aii
ill w liirli I 111' si ii'jiiiis lia
li)i.rii'al t iiiii'.
M illiT ( ri'i'k was lirsi pmspi'i'li'il inn lialrly aliiT I lir lirsl ilisi'nv -
i-\\ nt'y:ip|i| ill Iliis ii';;iiiii, w'lii'li was aliipiil |ss7, mi p'raiikliii (iiilrli.
A I'l'W years itisn il was llie liiisicsl spiil nli llie Ippcr ^ iikiili, liiil al
piisi'iil I III' rii'lii'sl iii::niii;:s liaxe liccii larjri'ly wiirki'il ipiil.ainl llii'
iii'u iliM'ip\ I'lii's ill I III' liiri'li ( ri'ik ilisi rid ami rlsi'W ln'ii- lia\ i' ilraw ii
iilV iiiipsl III' ilii' iiiiiiiiiLr popiilal iiiii. Ill llii' .viiiii'r nl' ls;i.".-'.ir, i||,.|'i'
will' a 111 III I ."pill I iiiiiiiTs ill I li s \ ii'iiiily. iiinsl ly mi M illm- ( ri'ik, liiil in
llic spriiij: iiim-i' than lialT'if llial iiiiiiilicr li'll Inr llir <li;,'u:iiius mi
lliicli ( ri'i'k. Ml llial 1 lii' I'lii iir iiiiiiilirr nl' men wnrkiiin' In I lie ilislriei
a I I lie I line il was \ isileil ( in .liil\ , is: ill) was niily alinill .nn. || is mi
M iller ( reek, lin\ve\ er, I lial I lie lieliesl s| rj ke yel iiiaileiii llie ^llkllll
ili;,'i;iii^'s was iiiaile liy .Inlin Miiller, who cleared rrmn mie elaiiii nl'
I 111 1 i na ry si/.e (•'•"" I'eel alnii;,^ llie lnil 111' llie ^'iilelija siini wliirli i>
xaiiniisly eslinialeil al s.'Iii.iumi in .s;,! i.iinii ;,s llie resiili nl' llie wiirk ><\'
r.Mp w iiili'is ami niie Minimi r. I )iiriiiL;' I liis lime lie eniplnv eil mi an
axcraire alimil s men, at limes as many as |s. payiiiu' lliem n|ii a
ilay in siiiiimer ami smiiewlial less in wiaier. In this as In nilur
cases it InnU smile lime In yi I t lie el aim reaily Inr wnrkillU' lie In re any
iriilil was aet iiall.N prmliieed, sn I hat il was ael iially wnrkeil I'miryears
ill all. Willi llie |iriilit alin\(' staleil. 'I'liis prnlil Is. linwe\er, exeep-
tiiiiial, ami allliniif,'li several nllnr men lia\e left Milli'i- ( reek with
"stakes" 111' xo.niiii III' .sl.Miu. yet many iimre have iiiaile mih
"ua^cs" — llial is, *|na day and smiie dn mil make lliat.
Sjiii/ii (if rtilli I/. 'I'lie leli),;lll nl' Miller { reek I'lom its jmii'linli wit li
Sixty .Mile (rei'k isalmul iil miles, and ilsemirse i^^ nearly slrai^ilil.
Tlie frradieiil nf ils lied is ei nsidi'ialile. as is the ease with all nlher
streams '.■< this rej;inii. .iiid this j,n'adieiil iiiereases sli<{lilly Inward llie
head 111' I he e reek. .\l the extreme liead I lie slope lieenmes \ cry slei'|i,
iliealiirle iiearl.\ enriispmidin^r w ilh thai nl' the sides "t' tlii'\alle\
t'artlli'i' dip>\ II.
Ill Ueneral the Vllllliy l.s V shaped. Iiiil ,il tin head it widens, iinl
slldWH a lelldelle\ In assume a linile clirved, or U-'^li"l»''l> 'illllille ill
eross-seclinn, thus sliy^jest iiiK H (jlneiill Mllllllllf ||ei|li'r nr einpie. Il is
indeed piiilmlil.V lo h'O iietinn that tills lintailclliii;.' and llalteiiiiiu
isdile ill the willlci' lee and simw .lei'iiiiiiiiate and lia\e a leiidi lli'\-
■IM'IIII I
ilfl,i M I)Ii.cilN(.-: Mil, I, Kit CULIK.
3-2 1
to move rrcim tin- iliviiliii^; iii|;.'i' iImuh tin- sleep slnpes wliieli llu)
rii])iill\ ciiltiii;; .stri'iiiri lias left; mi tli;ii iliiriiiu' till' s|iiiii;.' iiiniillis,
W lien the ice is surieliilli,' ilil'l lliell ilii,', llii> I lead ul' llic \ alley i> ncell-
pied liy a \ eiilalile t liiiiii.'li small and t ran-ieiit irlaeier. Tlie riinndiiii;
if the head •>( I
le \alle\' and its ;;radnal alleratinii into ihe luriii u| a
rin|iie is due ill ]iail 111 the iiiii\iii:: <>( the ire, lull perhaps iiiiiii«
lar^'ely In the erDsimi nl' I he ;rlaeial water-, « hieli .ire di-l rilniled ii\er
the \\liiile width 111' Ihe \alle\ in-lead nl liiiiiu emiieni laled in its
ImMIi
nil, as are the stream- lli.il ha\e nn dependenee nprni lei
tlie iee iiudls lineal liirniw - and dilelie- are Inrniid nn the udaeier, and
Ihe water llnwini: rrinii these and I'alliim' user the iie ifnnt runiis
watell'alls w liieh eliiirn up I he i.'ra\el and carry it duw n t he \ alley, so
thai Ihe lied rmdv is nrieii laid hare; and a- Ihe I'lunl nl' the ico
recedes this \ijfiiriins erusiun is hrnni^lil In hear npnii -iicces-ively
lii;;her parts nl' the\alle\, 'I'hi- aeiinii is nl' ecnnnniie inipnrianei',
since it |ire vents aceiimillatinn- nl' ami ten in- ;rra'. el- v\ it hin .ina- in
which it, ((]>ei'ales -a facl which ha- lieeii prnsed hy pr i-pi d iiiL:.
Tl
le lieails III' the nt her l; niche- in I his s ici
nil \' -Imw I he -ame tend-
ency In develnp an anipliiiheal rical rnriii. (Jlacier ( reek inpariicn-
r has a cinine w hii
iniich mure sNiiiniel rical than that nl' Mil
(reek
■\ plana I inn i- th.il mi d lac ier t feck t In
acier IS lar;;e
anil
llliile persislenl nil
accniinl 111' many springs u liicli rnrnish an
aliiindanl llnwnl' water I'min nnderi;rnnnd sniirci - and help materially
in I he acciimiilal imi n\' ii'c,
'{'he sleep sides nl' the Miller (reek \ alley .ire indented li> I'uirnws
ifullies, iisnalh' small. 'I'liese are c,
i\' I lie miners
This term appears
In I
ia\ e nri;rin
iiled in Miller ( reek, and since it has
spread all n\ er I he ,i;(ild disi ricls. as a cnnseipien I' I he seal lerin^' nf
the Milleri'rcel; miners, it ina\- lie nl' intere-i In mile its deri\ ,tl imi
as;,d\en liy an nid miner, Smiie yen- ann a miner li\ ilie name nf
Milller. whn irjive his n.illic in the creek. <ame intnihe possessinll of
ich he leaicd I'nr the piirpnse nl' rrei;:hl illL,'; I'nr ill this
cniinlrv Ihe dnif is what the reindeer, the hnrse. and the camel are in
snine imps, u n
it he I- ret;iiins. CnllStit lltili;; allim-l I he -nie HUM
US 111' I ran-piirl iiiu art i
cies Ironi place tn place. Mllller kepi 'ii- pll|is a slim't di-Iallce up 111
rasiiie, a little wa\ Irnni hisc.inip
Millers -eekini: tnr smiie term In
designate this ravine n-ed incall it '• the plice w 1
Mllller keep- Ilis
piip.s;
lint this Iniiu circnmlnci
ilinii liecaiMc natnrall.N siinrtcned ill
I
viirsc of lime, sn that the phrase w,issinipl.\ • Midler's pnp- am
event liall\ Ihe plural w.i- mil it led. and I lie r,i\ ine liecame '• Vlnller's
pup
'I'he lerni seel I In llll a -ap ill I lie limiieliclal 11 re nf I llu
millers, and frmii Miller (reek it wa- carried Im- inaliv hnndied inileH
ll lia-a perfectly delin it eapplical inn. Iieinu le-liicted
ll\ drv ravines nf very steep eradieiil which furrow
inalldirei IV'iiis.
to the shnri, iisiia
the hills and I nil inio lartrcr and well-marked valleys.
<lriinl.'<. Whaf lia^ 1 n -aid in regard to the character n( ilu»
IS UKOL, I'T ;! '.-1
;iri
\22 (;i;iii,ui,v nr tiik vrKti>; (ioi.D disiimct, ai.aska.
Ml III' I' ( I'l-ck \'alli'\ \v ill I' Hill ill- c II II' III miili'i'staiiil lid I it 1 Ih' nat iiri>
anil illsii'iiiiiliiiii (if I III' ^1 i-rjuii i:i'ii\ I'N III w liii'li i;iilil is rniiiiil, Ni'ai-
I III' 111 'ail III' till' \alli'\' I 111' re is a \i'i\ tlilii i'ii\ iTiii;: ut' ili'l lilal iiiali'-
I'ial. ami in many jilai'i's tin' Iti'il inrk is laiil lian', m' is liiililiii I'liim
tl lisi'i\ I'l' I 111 I \ liy I III' I hick LTiiivN I li 111' muss w liii'li I I'll! Is III i'ii\ I'l-
i'V I'lyl liiri^r I liiiiii;,'liiiilt tliis I'liiiiiliy. Al alimil -l iiiilt's I'lmn llii'
lii'ail llii'i'i' ari' :i iir I IVi'l nf i:ra\i'ls, ainl laillii'i' iIunmi iIh- I liii'kiii'ss
iiii'irasi's, iiniil al ilii' .jiiin-iiiiri wiili Sivlymili' ( ri'i'k il is alimii 1 ■>
I'l'i'l. 'i'lii'si' ;:ia\i'ls ail' maili' ii|i nC Hal ri'ay:iiii'iil.s nl' schist ami
liiiwliji'i's, exactly like llir mck iiiili'rii|i|iiiiL;' mi llic steep siiles of the
valley. These rrauiiiciits sliiiw sume slii;lil «aler act inn. in thai they
all lie Mat ami aie si lal ilieil, I in I are \ ei\ little wnril. '{'he leelileness
111' the cnrieiit uliich has aiian;;eil the ile|iiisit issliuwn liy the laci
thai inixeil with I he lai';;er I'lairnieiils is ciiiisiilei'.ilile tine ileiiilns,
which I he sli'eam has nut lieen si lun^.^ emnmh lu si'|iarate. In the
thicker liiaxcls the material is \er\ neai'ly the saitie rriiin tup to Itut-
tiiiii, except llial al the tup the materials slmw a lemleiicy In lieeume
liner, ami un i he \ eiy snifaee I here is ul'ten a luut ur I \mi uf line suit,
with l'e\M'irra;;nii'nls lit' schist. riirull;;li the npperour I feet uftlie
Lrra\els. ,ls seen in cllls ni.lile in the prueess III' miniiiL'. Ihere are
III ten la M 'IS III' rut I en muss ami wuml alternal inir " it li 1 he ,Lrra\ el, i mil-
eat Iiil: lempinary peiimls ul' \ i'y:i'tat inn.
The ;rulil lull 111 I is always at the I mi turn ul' I he jrra\ els, « liali'\ ii I he
thiekiiess may lie. tiiaM'l which cuntains ^ulil in wurkalile i|iiiiiitily
IS technically calleil "jiaN ilin." it is usually nut mure than 'I ur I
I'l'i'l thick, anil I'lum this runs iluw n tu a lew inelies ur less. 'I 'he lieil
ruck i!se|f,ai t he Jnnet iun with the ura\ el, usually euntains j,'uii|. ami
suiiieiiniis pa>s I'lir wurkin;; I'ur .is much as l' ui' ;> reel iluwn. (M'teii
this nppermusl /.um' ul' scliisi is lehei' Ihan the frravels.
'I'he ri'opieiil illver.aence liclwecn the chailllei ul' pa.\ illl't ill llie
;;raveK .mil the channel ui present ilraiiiai;i' is suinei imes ilne tu the
iiatniial wanderiiiti's ul the sircam I'l'iim siili tu siile. ami partly In
I'ui'ceil i'h,>ins;es III' piisiiiuii, such, I'ur example, as may he elVecteil liy
lamlslides. N'e.ii 1 he uppei'imisl limit ul pa,v .ltl■HVel^s a lanilsliile has
pllsheil Ihe creek lu tile Uurlll, pl'ui|nciH« a sIlLillt lieml. In the pri'S-
eiil creek liulliiiii there are unl\' :> ID- I feel 111' triaxels, while the laml-
slide in.iieii.'il w lien si rippeil a wa.\' rcM-als 7 ur >• feel i>\' uhler t;ra\ els,
which ,'ire alsu .inrileruns.
()\vin;; III the fact that the valley is V-shaped and that I he yrinlienl
is snllieieiii lu prcNcnt iiii.v eiinsideralile siltin^iip nl the ii|ipi'i'
liurtiun, iheyraM'ls are exlreniely liinited as tu wjillli as vvoll us In
ihickniss, the averani width lieiiiir |»liilialil\ nut mure lliaii rtll feet.
The lirhest },'ra\el. huweM'i', 'Upies eei'laiii iiari'iiwer •/.unes, (iiio III'
III!' I'ii'hesi spills which has been I'unml shuwin^'a pa.v streak mil.v 'll
feel w iili". allliiiii^^h it is 11 feel in liiiekiiess. 'I'liis pity sti'oiik isa chan-
nel uf ^'I'aM'ls rich III uiilil and Imumled un Imlii sides and un tu|i liy
■■■"'.
cfl.i II |ili;(iiN(i-: Mii.i,i;i; i UKKK.
3-.»3
111' luinc'ii iii,ilfii:il. It Miiiicli
lii'il III' llii- >lic;iiii MIKJ Miiiicliii
\\Vl-<'\ \\ l||ll|l-l- llli' |ll>>-.CIlt
1C> til iilir >i(|r .if II .
I» L'lil'l li.i-. mil hi'i'ii
I'll' «ni kniu' iiinliT
rur mIhiIII Jl lulli'^ :ll llll' MTV Ill'JIcl clI' III.' (
fiiiiliil ill Millii'ii'iil l\ larL'!' .'ii'i'iiiimlii! ioii^ ii>
]irc>cnl (•iiiicliliiui-,. Tiii-. !,icl is cNliliiiiii'il liylhc ^iciilir .iMiMiiiil III'
crusiiiii ill Ihi- I II llli nil 111' llll' x.ijjcy, ami I his is clue I III II !>■ Ill llll' sli'i'p
slii|ii', wliirii iiirri'jiM's llll' {'iiii'viii;,' |iii\\i'i' ul' ilfaiiia;,'!' waliTs, liiit
cliicllv III llll' rlVri'ls III' llll' liiral irlai'iiT. » liii'li lias ln'l'iiri' Imi'm ri'lci ii'd
t". A nliii^' 111 ll Iisi'i'val inns ul' iiiiiiits, iIh' rnnil nl' llii' MilliT
( ii'i'k ijlacii'i' ciiiiii'iili's \ I'l'v iH'ailv « il li I lii' ii|iiii'r liiiiii uf |ia\' iriavcl,
sliiiw iiiy; I lial llll' iMiiii' \ iiili'iil ai'iimi ul' llii' waii'is i|i'ii\i'<| I'mm llic
iiicll iiij; ii'i' pri'Vi'iils llii' I'liiii'i'iiiiaii I' llii' u'lilij |iariit'li's. .lust
Ih'Iiiw I III' ma vim II Ml I'Xlciisinii ol' l li.' liiiiiiuiaix ;,'lai'ii'i' llii'L;ia\ ^lsal■l•
lllill ami llll' ;ri llll is \ i'i-\ I'liaisi' ami |iii'si'iil milv in iiiiii|iaial i\ I'lv small
aim III Ills. SI I t liat il y ii'Ms, as a nili', sliirlii iiinlil. I''ai'i lii'i' iluwn llii'
cri'ck tli<> L'lilil 1 oiiii's liiii'i', Inil alsu iihhi' almnilaiil, ami tin- rii-tii'st.
11- LTI'aM'ls Mills lai' illsi'ii\ I'li'il. wliirh Is nil
Mill
rl' s clailll.
pail lit' I
aliiivc I't'li'i'iril 111, is sii iialril a iiiili' nr sn lii'Inu ilii'liiiiii 111' pay ilirl
ami ntlilains p'1'1 ill ^'I'itiiis 111' mi'iliuni si/i Slill raillni- ilnwii llic
• •reck till- ;riil<l 1' mi's nil I hi' wlmli' linii , a saiiipli' nl' il pi'i'sciilin;; a
vt'i'y strikiii;; cniiliasi wiih ilial lakni linni llii' lii'ail nl' llic ni'i-k.
'I'll i'(in;;lii lilt l In- w Imli' li'ii;;! li <<( i In' liiLTuinirs. Iiiiwi'\ ii-. ihi'ii- is nrra-
sioiiallv cnai'si' iX'M iiiiiiirli'il wiili ilii'liniT niaii'iial. I'Ii'its iaii>;iii;;
II' I'irlli's
I niiLri.'1'l laki'ii I'nim
ill valiii' I" rum •i'"i In "i'l an' I'niniiinii. 'I'
tlii'rri'i'k was rniiml alini:l hall' a iiiih- lu'lnu ilii'limil nl' pa> ilirl ami
wi'ii;lii'i| ."i niiini'S. Il I'liiilaiiii'il a small pnipnil inn iiri|iiarlz.
Il is iiili'i'csl iiiij; In mill' llial, hi'siili's I hi' ;;iilil rniiml in I hi' In 'i I i if I ho
main sti-oani, a iiiinilM'rnr llii' small raviiii's nr pups a Is nilaiii ^rnhl.
'I'llis ;j:nlil is I'liaisi', nwinir In lln- sli'i'p slnpi- nil wlliill il lii's, lull
('iiiiii;;li has liri'ii rmiml in I'lii'niirayi' niininir, sniin'iiiin's with lair
ri'siills.
/■(/')/(/.- ■riiiiiiiirhiiiH ihi' sriiisis whii'h rniisiiinii' iIu'Ih'iI
ni: li\ lilr. I.ailii' lilnrks nl' this
r>iiiiri( lit 1/
I'di'k an' many \ I'iiis nj' ipiaii/ rairyi
ipiait/. air i-iiiiiiiiiin in lln' .u:ia\ils. ami nirasiniial piii-i's slmw rrcc
ihl. Tlic laij:i' piins nC nisiy i|iiaii/. mi iiiishii
nu' aijil panning,
iiricli yichl iiiaiiv liiii' " i-oliiis" nl' ;;iilil. whih' llii> pyrilf wliirli is
si'paiali'il I'lnni llii'si' xi'ins ami alsn rinin ihi' srliisls (in wliirli it
iii'ciiis s|
pnradii'all.N ilissi'iiiinali'il I yifhl
nlil alli'i' mast iiii.
I'll
111 was also I'niiml In a i|iiarl/, M'iii in plai'r. sitiiali'il in
nlli' 111 I III-
ia\ iiit's ii|' piijis iii'iir llif lii'ail nl' ilir i-ni'k. Tlnsi' Iliiii;rs slmw that
;iii|il iM cid-s i|ls.s/;|/|jf|i|l<'i| lliniUfiliniii ihi'sihi-i .'iinl Ihl' ipiart/. vi'iiis,
ami is appiirciitiy assdclidMl willi pyiih' ami nihi'r snlphiili's: ami
h||ii'(1 Illf ^'l■(l\l■l riiiisisis cntiri'ly ul' (jiliilns iiniiu'iliaii'ly ih'iivi'il
lliilll llll'Hl' Kirlis, Urn MiMII'ff III' Hie placiT iinU\ is ipiiti- rcilaiii. 'I'lit'
^llll'lllli «lll»'ll fs liiill'il III CraiiiiH'iils 111' all si/i's in tin- v'nivi'ls. is alsn
(|('l'|Vlil| I'hMII (||'(|IInI|h In llll' si'hisl. Smh a ih'pnsil nri'lirs alinllt
IP
.■{•J4 (ll.(»l«J(iY i>|- llli; VI KON (lul.l) DISTKICT, ALASKA.
I.IKKI iVcl mIiiiM' till' ll|l|M'lll|il>l rl.-lilll llfillL' WOI'UimI III I^IM,; lli'l'l'tlll'
[.'.•ilcii.i cicc'iiis ill iircL:iiliir lildtilics ill i|iiiirlz M'iiis. (Mlicr ilcpnsilM
an- rmiiiil in I lie \ ii'iMit \ .
I.I. \rn II t 1(1 Ik
Till' liisi u^'ilil ilisi'iiN iii'il (111 ( ilacii r ( ii'i'k sitiiis IoIuim' I ii in
Is'.iJ. Ill lli.il ycjir, lidwi'V IT. lull lillli- work «a?<iliiiic lii'Viniil |iios-
I I in;; anil slakini;- (■laiin>. Tin' iiisiiny dl' I lie y:iilcli >lin\\s im riTunl
of •• liiHiiii>," liiii till' ,\ icid li.i- 1 n Tail' Iri mi I lie si art. In .liilv . I >'.'<;.
Ilicii' \M'ic saiil 1(1 lir al I ]'•<' iiii'ii al wmk. 'I'liis was Itiil IIuit
rmiillis 111' till' niinilii'i' i'n;^aL.'''l lini'iii;; llir nimi' Inisv part i.l' llic
spring si'a.siin, wlicn tin- .siippl.\ nl' wati-r wasanipli' fur sliiiciiiir.
Shi 1 1 II of' mill I/. Till' valli',\ <>( ( ilacii t Cii'ck is Vsli.ipiMl. nulalilx
in llii' iipjiiT pail, willi siiii's iniiiiiallv stri'p. i'S| ialiyun llii' mhi'Ii.
Ill lilt' III WIT part it is less t ii'iiclianl. clialiiiin;,' in ruini riinii a V ^'lad-
iially to a U as il upciis mil tnwanl (iuld (i-iM'k.
'rilc l^rlllliT sldpc nil llli' IKillll sidi', as rdlllpaii'il Willi llial nil llli'
sinitll, SI'IMIIS 111 111' ijlli' 111 llir niiirr liirrrl t'Xposliri' In tllf ra \ s nl' llli'
Sim ilui'iiiu llu> lull;; daxs of suiisliiiii' in tlir siiiiiini'i' imuillis: sn llial
I Ills siili' is siiliii'i'li'd 111 a ;rri'iilt'i' lii';.'!!'!' Ill' iliawinir and n-yfclalinn.
and ('iiiisi'i|iii'nliy wi'al liiTiii;f and crnsiuii lakr plan' iimn' i-apidl.\'
lliali nil llli' sniilli sidi', wIkti' iIh' rni-ks ri'iiiain Inr tin' innst pari
snlidly t'in/.i'ii I lirnlly:llnlll llir ;;:ii'al<'|- part nl' I lir slIliillKT. It is alsn
pnssilili' I hat a lilt nr iiplil't nl' tlii' i'i';:inn nii tin' iini't li may liavr npiT-
tlli'd til sliit'l llii'si' stri'ams siiiil iiwai'd. and I liilsi'aiisi' t lii'iii til inl irncli
liii'insch I'S ill till' snlllll sidi' nl' t lirir \ .'illrys.
II is also al nni'c nolici'alili' lliat I lie sniilli side nf til.n'icr Cri'i'k
N'ailry is ninr inspiciiniisly t'lii'nmi'd liy sidi' irnlclii's, ni-. in miiiiTs'
laii,;;iiai;i'. "" pups," I liaii istlir imrllisidi'. Tlii'si' pups, alimil a liail"
dn/.i'ii in iiiimliiT. vary t'nim iialf a mile In _ nr ninri' inili's in Icimili,
and ari' nl'ti'ii sliai|il,\ t ri'iii'liaiil nr V-siia|»'ii. slmw inu' a ;;ri'at ('iinci'ii-
t ral inn nl' (in« ni'iitt iiii: li,\ tin' iitt If st rram wliidi drains tlii'iii. 'i'lii-ir
;;radi('iil is. nf cniirsi'. mncii stcrpci ilian I lial nf I lie \ alley ny main
y;iilrli, linl,iiki' tlii' main \ alley, eaeli imp nsiially In-ads in a rnn;rlily
amphillii-at rical fnrni nf its own. Nnrnially, t lir pups an iipicd
iiy \ cry small si reams; in sprinu't imc. Iin\\c\ cr, w licii melt in;: is rapid,
the claims at their mm it lis a re said m he iiincli harder In wnrk, liy reason
of the siipcraliiindancc of waii'i' which tlicy iliscliar;j;i'.
'I'lic head of (i lacier (reck \' alley is (|ii it e steep and is of I he amplii-
lliealei or cir(|lle type. The fnriii seems In lie due In Ineal ;^laeiers nr
masses nf slid w and ice w hieli aceiiiimlale in the heads of the ;;iilclies
during- the Imiu cold winters and usually melt dniiiiu' summer.
Where the condilimis of precipilation and allilmle of the head of the
;f|ileli ill relation to the sun's rays arc favorable, the aeciimiilal inns
ma\ 111 me perennial, as seems to he the case al the head of Sipiaw
(iiileh. near w here the l)a\i;- (reek and the Miller (reck I rails m 'pa rale.
l''roin the more than ordinarih' liiu:li di\idi' here, the head of the
ill
'iii
»ll 1111 1
ill'l.i II l>Iii(.!N(.
til.A< II l( ( i;i IK.
•A-2:
lllc'll lIc'si'clllU \iT\ Mlinl|(ll\ 111 IIji' MnrlllHi.^I, ^11
111 liilllMltll'il il- l.lll'
iii'rilii; iliiriML' iIh'
ii'cii mill iiiiH'i' 111' II"
mil iiiiiiii;.' Ill iiii
UN llll' Mlillilll' 111' .llll> I l-^'"'') : ll«.ii|il,lll|i> i|i'|liiMt ill' ^liiUN ;|||i|
M|l|ial'l'Ml l,\ IIHil'l' lIlMII Vtllllllj III' li'IrliiM'ii hv I
I'l'iiiaiiiiliT 111' I III' oiiiiiiiii'i'.
I ilacii'l' (li I'U i|i'i'i\i'> il> luiirii I iiiiii llii'-i'ji
I riiii>ii'iil !.'l.■||•il'l•^. Nsliii'li 1111111 i'M'i\ wiiilii-, aiiil.
(|ii\Mi mil il lali' ill I III' « iiilci- 111' »|ii'iiiL;. iiiali'riall\ iiiiiil'i-ii' in •..uin'
Inralil ii'> ^^ il II llll' lllilirl-s' NMH'k. Ill I III' ll|i|ii'l' pall 111' I III' L'llli'll li'lli-
iiaiil> iirMiiiic 111' I lii'M' ^lai'ii'i'Mliiiilil li'ss liii;;i'r Iliiiiiitjiiiiiii till' MiiiiiiH'i
III' 1 1 Mil' pi'i'i'iiiiiah I'lir I'liiisiiji'ialilv Ih'Ihu i lir ii |i|ii'i' I i unto ni' u Ih'I'i'
|iiiispi'i'l in;; lias liri'ii cairirij mi, a-- lali' a^ I Ih' iiiiiMli' nl' .liil\ i In' rn'i'k
liaiik-- al rn'i|iirlit iiilrrx als I'm' -.1 iililii's ni' Im' •»■ iiiuit' \ ai<U wcri'
I i III 'I I I IV ii\ I'lliaiiyiiii,' I'l ill's III' siijiil III III' ii'i' '. Ill' ■■ I'l'ci in iliirkiii'*-
All I 111' ;:iil'l laki'ii mil 111' < ilai'iiT ( I'li'k lias ln'iii uliiailii'il li\ piairr
liiiliin^^: i'miM'i{ni'iil l> Irmii iii'ai' I In' iiiuiil li nl' lln'i'ii'i'k In \\ illiiii a
mile nr sii III' iis lirail llll' \alli'\ has liccii siaknl niT. making' smni'
sixt.v claiiiis ill all. .\ I'laiiii mi (ilai'iiT Creek is ."iiin ii'i-i in |i'iii;i||.
liH'ilsilii'il paialli'l Willi iIh' \ all('\ . ami i-xli'inU laii'iall\ I'lniii rim
rock ti> rim imk. nr as I'ar in 1 liis iliri'climi as i lie _-ia\ il ili'pii*it> ma.\
iiiTiir. In llll' iipjicr m V-sliapi'<l pari ul' Ihe \.'illi'\ lliis laleial
I'Xii'iil III' till' yraM'ls is usuallx \i'r.\ limiiril, nl'li'ii in Jn \ari|s m- le-s.
« liili' in I lie Inui'f pari, as in I lie \ icinii \ nl' I lie I >isi'ii\er\ elaiin. it
allainsa wiilllinl' rrmii J-"i in I r mnre yariK. 'I'lie ihiekiiev^ nl'
I lie LTiaVels is mil\ S feel nr less ill llie upper pari 111 Ihe \aile\, Iim;
inereasi's ;rrailiiall.\ 'III" iisi ream, until a I liieUiie-s nl' I'n nr iiiiii'<. Cci'i
is leaelleil.
/;,'</-/'nr/.'.-riie i.eilr
ii'k III < ilai
lltil'lllileinle sellist. nl'lell yrapllilie
ier ( I'eeU is n ila I'l /- III ii'a sell isl . Ill'
•I'lli- rni'U
nlllailis llilleli Iri'i'
ijiiarl/, ill iiime or less eoniiimniis mmiis. Ien«.e>. ami lari;i' leii! ieular
ami irri".;iilar masM'>. Near I lie lieail nl' I lie u'nleli. mi i lie upper sinpe
111' llie ili\ iile lielweeli < ilai'ier ami Miller I'leek-., '-i i a liilinla III is llie
ijUailz llial ill plaees il I'mnis almnsi lliewlmle i k. Miieli nl it.
Iinweser. is in llie rnriii nl' lesiiliial linw I'lers. wliieli lia\ e prnhaiiiy
resiilleil rrmii Imii;' peiimls nl' weal lieriiii;
wlliell I'nl'llierh inelnseil llieiil.
.11 nl' !l
uiiil rv nil
Tile milv plaee in llie^nilell u lie re Ll'iililliearillir i|
iiii: iiiiarl/ lia-- lieeii i\[
II. .1. lieln
« |>l>en\el'\
liiwar.l tin- Inuer
rl/ \ eill I>^ inelies in I llieklless iselaimeil
eovcreil in plaee is on elaiiii N
part III' llie ;;illeli. Ill re a
liv I lie iiu iii'is In assa > s.-, ||, ■ Inn.
■riiwanl tile heail i. i lie •.•nleli. where Ihe rnek iiiiteniiis near the
ereek, the strike nl' ill.' -^i hisliisit.v is N. 'M K. ami the ilip -.'."i SK..
bill larllier ilnw 11 Ihe ilip seems 111 1" mii'lliwanl. In Ihe Inwer pari
III' tlie^'llleh the slrike
if si'hi--ln,vil \
N. I I W . anil Iheilip is 1.' N.
( )|l the I'iil;,'!' linl'lli nl' (ilaeii
(tip S SK
r ( ri-'k the strike i-
N. IJ K. an
Urm'i.l.t. — The I'ra.^iiieiils in the ■;i'a\els are niaile up enti,el\ nl'
IMAGE EVALUATION
TEST TARGET (MT-3)
//
1.0
■^ I^ 12.2
! -^ IIIIIM
lyub
1.8
I.I
L25 iU lil.6
— 6"
Photographic
Sciences
Corporation
33 WEST MAIK STREET
WEBSTER, N.Y. 14SS0
(716)872-4503
1
'1' •
;■ m
i »'
;i2(( (;i:oi,(i(iv ov tiik yikon goi.d district, ai.aska.
scliisis jiml (|iiiicl/, ilcrivcd I'l'diii tlic adjacent licil-rcick. In tlif iijijicr
pari (if tlic u'lilfli llioy aro more aii,i;iilar tliaii in llic lower jiarl, and
Ilic di'posil SDiriftiiiK's rcscmlilcs laliis; rarllicr di)\\ii tlic valley sand
and clay appear and furiii a conspiiiidiis jiart of lln' deposits toward
the nioiitii. 'I'lie I'ollowini;- vertical section, rou^tily eslinialecj on
<'laiiii -'ti, above the Discovery claim, is a fair averaije of tlie jrravels
for Die middle and njiper part of the ])resent di,u^i,dn.us:
Sirtiiiii ( fniiii Iti/i iliiiniiri(ril) im rliiiiii .'", idiarc tlic l)isc(>r('ri/ chiiiii.
1. Alhiviiil soil anil moss. Neiiictiiiics nincky IJ
V,'. Pflibles iif (]iiiirt/.sc'lnsf as lari,'(! iis the liancl, with bowl-
ders iif iinartz often <i inches in diameter, and a few
i^niall bowlders of iioi'iihyritie dike rock; tlie-o are
mixed with some sand. 6^
I!. Alluvial soil or juaty mu(dv, (dearly a surface formation
(!,'('nerally. tliiiui,'h not always, jiersistent) - 'i
4. iTolddM'arin^t line ^ravtd, known as " Chickenfced" by the
minors, restinf^on biMl-rock 10
;.'0
The coarse iiravel (No. :.') is often interstralifk'(l withtliiii layers of
iin[)erfeclly stratified soil and ,sand. 'I'licso inters! ratified layers are
horizontal, but show some sliyht criinii)linjj;. as if they liad been
dejiosiled on ice. at I he subseipieni melt iiii; of wincdi they settled down
to their picseiil attitude; or Ihey may have otherwise sufTered dis-
iMidianee by ice nn>venient while yet near the surfaei>.
'^onie of the(|iiart/. bowlders in these ujjper trravels are traversed
l)y small veins of pdeiia; also upon and in a fi'a^'nient of scliist was
found dissenunateil niala(dnte. In the lower layers or " |)ay irravels"'
(No. t) are found frau'menls of botryoidal iron ore. In the .tridd from
these uravcls occur nufiiicis up to several ounces in weijrht, often with
crystalliMe (puirtz still adhering', showinj;- (dearly tlio oi-if^inal associa-
tion of the two.
F'liKKii I ur,i;K.
I'oKci' (reek or (inhdi ris(»s in the liald Hills. whi(di form the
divide betv\e(>n l'"ortyinile and Sixtymile cre(d<s, at a point !(• miles
southwest of the ^■ukoll. Its. source is op|)osile the head of (ilacier
('re(dv. IS miles from P'ortymile ('re(d<, ill the drainauc basin of whi(di
it bidoniis. .Vecordintr to a prixdamation issued by ('a|itain Cmistan-
tiue, i>( the Canadian mounted jiolice. at Fort t'udahy, the one hun-
dred and forty-tirst meridian, which constifufos Hie iiiferiiaf ional
boundary line, crosses f'okei' <'reek 1 mile below the divi(l(>, <rivinir
to IJritish territory 1 nnle of its headwaters, 'i'lie line was surveyed
by .Ml-. W. y[. Ofjilvie, of the (ieolomical Survey of Canada, from its
point of intersection with the Yukon southward nearly to Sixtymile
Creek, am! its course is marked by a cuttinj; Jit feet wide throuf;h the
timber straiglil acro.ss count ry. In IS'.i] a rnifed States Coast Survey
-r
J,'
H * - ■ •
SPCHK. {
fiiLrii niGcivfis: pokkk cuikk.
;5_'7
party 'li'ici'iiiiiif'l tin- luratjnii ui' iis inici-MTi ion wiili llic Viiknn ami
Willi l-"((i-l yiiiilf (i^'i'k. iiut a> yi-t tlicii' lias lii-cii im ciMiiM'ial ion Ici
(IctcniiiiM' oihcr iminis un iIh- lim-. A irri^al iiiuiiIm'i- ni' t lie iniiicrs
arc iinrrasniiahlx iiu-iim-il i.i ili>|nilf l ln' ai'>iii;n\ nl' i lie siii\ |.\ , mihI
many tliiiik even lliat MilliT ami (ilacii'i' c-ii'i'k- air in Alaska. Iml,
so far as we an- alilf to jiiiliTf, iIhtc i-~ im ii'a-.iin Im- tlii- liflii'l'
IldwcviT. till' l.H-atiiiii lit" tin- lniumlai\ has iin iiM|Hii lami' i>\> I'nkiT
Cr'Cfk, I'm- all lln' paying i-laiins an- wi'll uiiliin ilic' Alaska liiiiils.
Last spiiiii: ( 1 s'.ic, 1 ihi' tiiM wmk was ilmii' mi Ilii' i^iilcli. anil in lli'
iiiidilli' of .liilyuiily tini-i- i-iainis \v<ti- wuikini;. Tlii'-i' aif all al nr mar
the niipillli III' liii' iTi'i'k. Till' liivv sla^'i' nl' waliT «as ;i liiinliani-i' tu
sliiiiMTii:, tliiTf l»i-in;r liaii|l.\ <Miiiiii;li water lip i-uv ir I lie rilllis in the
sluici' liiixfs. I>ilt a"> the <-ri-i-k lia<l heeii diiciumI sn ii'ci'iit 1\ . liiiie
that wuiilil have lieen alisulnlely lost in a later slaire nl' ile\eli)|iiiienl
was put in Ik truiwl ailvaiita^re in striiipin;: i he harreii •:ra\ el and in
other ileail umk.
Sill 1 1 II III' ml!' '/• — I he head "f I'nker ( reek is all am pli it healer with
small tun-eiitial liram-lies ami steep ^nillie-., I'rniii the main divide
the deseeiit is al lir-t very sudden. IpeiiiLT li\ liannneler iiniit'eel in a
little over half a mile. For :> miles Itelow lliis llie fall is iriadual,
heinir sea reely over I.lo feot to the point where I'oker Cieek enters
Walker I'"ork. 'i'lie valley is rallier wide, willi side slopes axerairiii;^
:.'o near the liouiidary. and Iteeoniin;: less sleep farther down. .\t
the inonl h. tiy the eomliiiied erosion of the I )a\ is. I'likef. and Walker
l''ork. holt Dili lands half a mile wide ha\e lieeii formed and I he lid^rcs
have been ledlleid to si itll.rollinir outlines. These uellt ly ell rved
riilires are termed "" houdiaeks."
The cause of the sleep irradi' ami aiii|iliitlieat lieal form a I the head-
waters is. as upon tilaeier (reek, ilue to the fael thai for a part of
the year the valley is oeellpied liy Slli.ll Ldaeiers. .\l the time of
visit, ill .Inly, areas of siiow and iee from a hiimlred square yar'ls to
an acre in extent still existed at the heads of nianv of the smaller
hraiiehes. "I'o a limited i-xleiit. therefoic. the snow is |ieiennial. for
alioiil the laller |iari of .\u.i:ust or the lirst of Septeinlier the lirst,
snowfall oeeiirs. Sunn- nieltiiiir .i:oes on iiiili! I he last ol Septeinlier,
hill after that time tin- aeeumiilatioii exeeeds the inelliii!.' until the
month of .May. I'reeipiiai ion is not trieai in i hi-- part ol' i he eon n try,
seldom over I feet of snow reinainini: on the level lliroiiLihoiil the
vvinler. The eiiiiditioiis are favorahle to the foitiialion of an iee
lield. or m-vt'. durini: the eii:ht inonihs of vv inti'r. There is almost,
no motion, however, iiiiid the meltiii;: in the middle ol May. then
toIll,Mles of iei- are sent down the slopes, the iee eats haek al tile head,
the silp<'i}xlacial. and in a less de-rree the siihirlaeial. stieanis lend to
widen the valley, and the eiriple form is inteiisilied. 'The irrealest
' elTei't of this Ldaeial aetiiin i> shown ai tin- head of the valley, for that,
is the reiri'ill where the iee reliiaills the lollLtest. livlhe middle of
;')-JH (iKoLO'.Y OK THE YUKON GOLD DISTRICT. ALASKA.
•luiif llii' Miow lias i)i;i<;ti«!iilly all di.sapitt'Jirfd ft-
lie lower valk'V,
Icnviiii,' Diily small i)at<-li<'s on the liciu'lits ami a1 llic heads o
aviiios.
On til
e SKles I)
is MTV act i\ e ill
\ve(v
fi
r ti
IIS cirqUi
lusideraltle talus aeeiiiimlates. Frost
Itreakiiij; ilowii the elilTs, since there is scarcely a
(liiiiiij; the whole ye.ir when the teIlll)el•atnI•(^ docs not fall lieiow
t a* least once: the diurii.il raiifre of leniperaturo is ;ilso
•ceziliL; polll
very irrcat, son ■ limes as mm
ther<
h as 'iH de^'recs in summer. AVherever
the slif^htest holil l<>r ve^'etatioli a thick carpet of moss
coV(M's evervlhiny: and serves to protect t lie surface airainst the me-
chanical action of rain water. There i-. howi-ver, a How of the vejie-
t at ion down tin- slopes, the effects of which are observed upon many of
the steeper liloss-
overed hillsides all alonj: the l-'ort vmile-Sixt viiiil
divi
ail' especial
Iv noticealile at tin- heails of (iold, (ilacie
and Poker creeks. The appi-araiice presented at a distance is that of
escalops. These are foriiieil liy little rid^'cs of moss which lie on tliti
slope, convex <'iid downward, resemhlinu' in miniature the terniiiial
moraines of a ^rlacier. The riilires are din- to a slipjiinfr of the thick
moss a id decayed xcuclalile material upon the fi-ozen subsoil or roi'k.
The movement, like that of the j^lacii-rs. takes ](lacc only i)art of Wio
year. In the winter, when both the moss and tin- untlerlyinsj; soil arc
frozen solid, there can be little or no motion, but with the first nielt-
iiifl a dowiiwaril slijipiriir beirins. As the meltinu i)roy;resscs more
and more o
f th
iiiick'" iiioM's: but there is .-i limit, fjenerall.v not
more than IS inches below the surface, where the ground is frozen
tl
le vear imi
lid and there is no motion. Sometimes there is a sm
escalops, the rounded iioinis of whii'li travel faster than
dell acceieratioii. ami a slight landslide is the result. Obviously,
owiiiir lo the diirereiiees in aiiirh' of diffi-ri'lit parts of the same slope,
the dowii-creepinji; will be differential, and the resiilfi is seen in the
waves or
the sides.
lit il-riifl:. — (Ji'iierally after the fii-st sleep descent the valley is
covered with moss. Here ami tlicre. where the stream has umlereiit
a bank, where a landslide has occurred, or in the bed of the creek
itself, outcrops are found. The i-ock is the saiiii' for f ho whole length
of the valley — a bluish-black qiiartz-sdiist. often grai)hifi<', coiitain-
iiig many (|iiartz \-eiiis which are usually parallel with the schistosity.
From the divide to witliin IJ
liles of the mouth these ro(dvS dip
'.ikI strike a little north of
gently to the south, generally not over
east, ])arallel, for the most part, with the direction of the valle.v. .Tu.st
above its jiinclion with Walker Fork a low aiiticlim
les in, strik-
ing N. W° K., and th
a revei-se dip of lo" to 1.") to the northwest.
(imrrJu. — .VliiiosI all of the gohl is extracted from the bottom ])oi'-
tion of the gravel resting on the bed-rock. Tli
IS pay
dirt.
ihicli
coiii])o.sed of subangular, waterworn pebbles of ipiartz end schist,
^■aries greatlvin fhickncss and width
th
ith it is ;i feet
thick, and from liere toward the hea<l it thins out, until at the highest
•laim,
liles from the divide, it is not over 1 fool thick. Above the
M'
n]
T?
»
6Frim.]
GULCH niGciN'ds: i-oKr.it i lii.r.K.
:5-_>!)
pay din (■(lines ,i layer of barren ^.navel 1 lo i. feel tliick. This is
•generally eoniiiosecl (if idnnded or llaliened fiaLrmcnis of vein (|iiarl/
ami (inart/.ilie seliisi . coarser than tile pay irra\ ds and showiii;: h'ss
till' elTeels of assort inent liy «alel'.
Tiiere is a iKipiilar impression aiiionu- tiie miners that the very often
tliiek •rravels in this and other Lrnlches are composed of maleriaK
transported irreat dislain'es, and that the aireiit of transportation
was a irlaeier, rather vairnely tlidiiirht by them to lia\e o\crriin
llie whole eoiliilry. There is nothiiiir, howcxcr, to justify the idea
of a continental lihieier. or even a valley udacier of Lrreater per-
niaileliee than the t ransicnt ones before (|eseribe(i. The pebbles and
lM)\vl(lers coinposin;;- the i;favels ha\ c a dist iiietly local origin fi'oiii the
iiiiiiKMliate draiiiau'"' basin of I'okcr Creek. In part the (leposits are
stratilie(l, and when thoy are not so there is e\cry other reason to
Ixdieve that they were laid down in the \ alley of a stream. .V certain
arraiiLTcnieiit observe(| in the iipp(M irravcl at .Mc( 'larty"s claim, thr
quart ers of a mile from the month, showed that 1 he deposit, now s or
in feel abiiv'e the stream bed, was formeil in rnnnini: water. .\\ this
point bowlders of stretched (|uart/ite and vein (piariz. some of them
afoot in the loiitrest diameter and -'i to ti inches thick, are aiiaiiy^e(l
with their longest a.xes |iarallel and incline(l downst ream, jnst as in
tlie present stroain bed. The aii;:le ot' inclination is about l."i from
the vertical, sliowinjj: that deposition was made in swiftly riinnintr
water. Xot iiuieh ditVereiiee was noted between the upper and lower
gravels. If any, there was iiuire saiul in the paydirt than in the bar-
ren jrravel. showinjr, perhaps, a slower current dnriiiir the lirsl deposi-
tion; lint, as a whole, the deposits are coarse throiii:ii(iiit and \f\\
similar to those now beiiii,' laid down in the bars of tl reek. 'I'lie
gravels have been cut into by the present stream, snir.irest injr that the
relation of Poker (feck to its base-level has changed. Kither there
has been an elevat ion at its head or the level of the main draina;:e of
tin? count I'y has chanued. In either case the creek has acipiired ncu
aetivily and is eorrading the older (leposits. In this revival the old
stream valley does not always correspond with the new, for while in
llie lower part the pay streak has been found near tln> north side of
the creek, pros|)eels fai't her 11 p have shown it on the op|iosite side.
However, owiiiii to tin mparalive nai'rowness of the \alley, the
liK-atingof the pay streak is nearlv always easy.
OiriiiT' lilt of i/olil. — (iold occurs ill greatest (piai titles within 2
miles of the month of the creek. On the iipjier part of the creek it
is absent, or is found in very small (|Uanlit ies. It is bright w-llw.
in subangular to angular grains, which are seldom over ii.(>s ouik . in
weight. The shape of the grains is suggestive of a near origin.
No free gold ill (piart/ Veins is known on I'oker (reek, allhongli a
few small niigu'els, in which the gold has adhering to it pieces tif
quart/, which have not lieeii worn otV durinir transportation, have
been found.
h 1
ayO (;);oL<)(;V of TIIK YUKON OOI.D T)I!<TIMCT, ALASKA.
h.W l> * HKKK
- i.V
On Davis ('reck claiins ai'i' si;
Tccl ill Icii^rtli, ami aro oocii-
IiIimI ii|i Id williin a iiiili' and a liaif of tin' <livi(lc. Alinvf tills point
prosiM'c-i- lia\i' sliiiwii lit til- pax. Allot' tin- claims arc on the Alaskan
side of the lioiindary. With the icsl of II;" KoHymile ilistrlet, this
c-reek siilTered I'loiii the loii^r-eoiil iinieil <lroiii;ht, and at ihi' time of
our visit was pi-oduelni; m.tlilni: liecatise of the searelty of the water
sil
p|)ly. Ten men were doini: deail work on the elalms, and were pre-
pared to shovel into the lioM's
w it h I he lirsl rain.
of I'<
ijii 1)1' mill 1/
-Davis (reidv rises iiiree-(|iiarlers of a mile north
t'rcek, ami with the latter I'orms the head oi' Walker l'"ork
jf J'orlymile (reek. The head is ami)hitheatrleal, allhoii.u;h not so
I'oker (reek or as Sipiaw (Jiileh. At the very
ehar.-ii'terisi leally so
liead the descent
then hecomes lapidl.X' Ic;
is sleep. hcillLr ■i'"' feel In olie-i| Hart cr of a 111 lie. aiul
.">e\eral small laxiiics come in from the
iiort li.
TJ
■reck llows throuirh a narrow \alley toward the west.
Tl
fTcntler.
iree mile:
conies le:
I rolll lis source 1
I licmis to llie southwest, Ih
■■Iccp. till' \alley liroadi
111
>l.
if 111
Md<
The valle\s of I'oker and Davis creeks are markedlv dill'creiil. In
the i'oriiier the steej) u'ra<le Is at Ih
d and the reniainder of tin
cree
k (I
ows more
(wly Ihroiiuh ;i i'oiii|iai'al ix'cly
broad valle\': bill
Davis Creek partakes more of the nat iiic of a torrent for the (irst part
of its course. This, toirelher wllli the iiisli;uillcance of theelr(|Ue type
of head, seems to show thai I he ■ re has not been an,\' very ureat amount
the absence of spriiiLfs,
of
LTlacial ai-lioii.
or some reason. perlia[i;
there has not bcc!i as iniicli acciiiiinlat Ion of sikh. and ice as in its
com|>anion
iile\', and ordlnai'\' water
corrasioii lias liceii more impor-
tant ill the dcirradal ion.
Ill il-rmk. — I'ortlie rn>i :; miles Davis (reck Hows iiaralhdand near
to the axis
geiith
of an anticline and on the soiitliern lliiil
Thedi
Host ne\er o\<'r In . to the south, ami the striki
p IS very
east and
west. T'orlhi' last J miles the st ream crosses t he st met lire, ]{i'versed
dl])s are met, and an unsyiiiinetrlcal syncllne, stee[)er on the north
than on Ih
■eolith, IS crossei
1. Til
followed to the .south bv tl
Poker (ri'ck anti<'line, noted abo\e. On the whole, h
owever. those
re minor plications in the soutln-rn limb of a ^reat anticline st riki
a
east and west.
T
le Kei
l-idcks here are the sami- as upon I'oker Creidv and Ihe Si.xtv-
niile divide — schists derived from i|iiarl/.ltes, in which ((narlz xcinsof
vary inj; width niid cxlcnt occur parallel to the schi.stosity. Secondary
mica is fre(|iiently developed, sometimes iriviii;; the ai(pearaiie(> of
ijrneons rocks, but upon close examination the metaiiiori)hic charaetcr
is seen. Often there are ^rraphllic layers correspond I nj; to orlfjflnal
hese irraphitic schists were parllenlarly noted on the
■sluiiy portions. 1 he:
Discoverv claim, one-half mlh> above the month of Ihe creek.
Sl'ini:.)
(in,< 11 DHii.INdS: nvNIS CIJI.KK.
3.11
(.■/■(inlN. — 'I'lif ,i:i-a\-.-l lias llif sain.' dia laiMiTisI ii'> a> that mT {'..U.t
(reck: ils tliii Uiics>. hcAvcvcr, i- UMiall\ imiI s,, -n-al. \i'ar 1 he
inoutli lln' >ci-li(in is as I'dlldus:
Stfllnii II, til- till iiiiiiilli ff IhiriiJ Cm I.:
Muck (ve<;ctal)li' iiMitor kihI m'iI •
C'oarsi- i,'ravi>l i bowlders oftfii s im-li.s in iliaiiu'Ii'i- 1
KiniT -i-iiv.'l, pfil.M.x, au'l litt!r sMiid; .-...ir-iT ai l.ott..in
I'icil-rock, Mark siliii'Dus srliist.
i;
t
I
Till' lowci- I Ccrl isllic •■ ]ia\ iliiM," and il \arics Im.iIi in lliirkin'ss
ami wiillli. Al 111!' |)isr(i\ci'\ claim the lliicUiicss is I iVcl ami ihc
width is sai<l I" lie In I'cct. l''arlhi-f ii|isli-cam thiTc is a dc^crcasc, ami
al the last claim il is unlx i' Iim'I lhi(•l^, willi a wiillh ai imisi di' .", iVcl,
The tol.'il thi<'l<ness(ir till' u'l'Jivcl also dci'i-eascs in i1h' up^licani ilircc-
tioii and is hai-dl\- osci' c iVd in the nppcrmnst wm-kiiiiis.
The lied-rnek umliT the •^■ia\c-l is locally decumjinscd ami disinle-
'n'ate(l tn a depth nf i'. i>r s inches, and in this laxer dl' rutti'ii im-k
ciiai'se. well-woiii .i;nld has urtcii 1 n lonnd. The dcci,in|Misil inn
iiiusi ha\e iMMne alionl snliscipn'iit tn the dcpnsil inn cil' the ;ri-a\eis,
for a stream si i<pn,i; encm^rli Incairv lai-,i;c liowldeis would ha\e swept,
awa\' any |M'ee\isi in^' mass nl' deca> c'd rock.
Sdiii-ri III' (/nhl. — The L'lild I'lnind ml l)a\ is (reek is coafse; the
Ui'ains are sonietiim's r()nmle<l. sonn'tinics llattencd. Ilsmiirin may,
llieret'iire, not lie far distant, t he riMindiiii;- haviii;; 1 ii dne to the
[loimdin.i: of rocks cariicd over ami licyomi the v'<dd, rather than to
attrition etVeclcd dnrin,^ adnal I I'ansporlal ion ipf the [lartieh's I hem-
selves. In some ca.ses fraumcids <d' (p:arl/. veins an- fonnd in whi<'h
u-old occnrsin disseminated plates ami stringers. <^>nart/. veins occur
here. as<in l'idici> Creek. e\ crywln're in tlw schist. On l.owry's claim.
1 mile fi'om the month, oi f these vi^ins exandncil lies liorizonlal
and is In (H' U' incln's thi(d<. So far as opened np il eMcmls latcr.-dly.
parallel to the schistosiiy. I'oi' i'.". feet. Macros,-,, pically the quart/, is
cross(>,l liy , 'racks, whi,-li ar<' often occupicl \<y rnnonite o; hi'niat it,'.
These are jirol.alily d,'rivc,l from tlm ,,,\i,lalion of ir,,n and .•■ipper
pyrites, whii'h an- seen in minul,' sp,-,d<s. I"rc,.' e-ol,l has l.c.'U f.nind
li',M-e. ami on.' speidim'n in which was a llak.'of .u'ohl one t hirly-s,-c,md
of an inch in ,liamet,'r was -iven ushy ,Mr. I.owry.
■|,H KKN I uta,K.
The hcadwateis ,,f (hi, ken ( iv,d< aic diviiled from l-'raiiklin (liilch
by only a narrow ri,l.L;v. hut I he iieneral dirction of ,lralna^e in the
former is al ri.irhl an.udes to that of ih,' 1 liter, s,, that the tw,) stivaiiis
outer Fortyinile (reek about J-"' miles from each other. Asc'iidin^'
tho rid.ae south of Franklin (iiilcli, one has the wh,.le basin ,)f ChickiMi
Cri'ck and a wide expanse of country farther t,. ih,' south .sprea,! out
before the oyc, ami it is at once noticeable that the toiM.iriaphy of this
: n
;fl
.-i
y;5:
(IKOI.lKiV or TllK Yl'KON fiOMi KISTHKT, ALASKA.
coiiiili'V i> iciiiailv!il)l\- "lilVcrciil fniiii tlifil (iii llic iiorlli side of llic
ridv'i'. Jiiiil imlci'il I'roiii most nC llio Kortyiiiilo district. Tlit' coiiuliy
to the soiiili is iinmd and p'liliy slopiiii,', and is slifflilly and cvt'idy
iiKli'iilfii \t\ stri'Miiis wiiicli rise in a low rid^'o with I'onspiciioiis cluiiips
of liills line and lliiTf. Tlicsr liills jirohaliiy form tlic divide hclwccn
till' Tana na and llic N'uUon walcrs. and arc l<no\vn as tlio Kclcliiim-
stock Hills, from a Iril f Indians dwelling,' In Ihcir vicinity. Dcn-
nison l''oi'k I'iscs in a conspicnoiis plateau, well mai-ke(l olf ffom the
sloping- plain, and from this plateau i'iscs a doiililc or triple cone
wliich sni;,i;ests a volcano, whili'the plateau itself siiirj^csts a lava (low.
'I'his mountain. howcNcr. is saiil to he of Lrranile hy jirositcctors. who
lia\(' jjiven it the name of Sixtymilc liuttc.
Chicken Creek itself jiarlakcs of the i>cculiar to|)oi,'rapliy .just
described, foi-. as shown on the map, its various brandies drain a com-
paratively « idc bell,
they ha\e cut coinparat ividy slijfhl \ alleys.
Jliil-rinhs.- A\ the head of Chicken Crcidc oiilcro|)s the larjjc srraii-
te dike which forms I hi' crest of the rid.i;e between Chicken Creek
ind I''iaiiklin (Jiilcli, while the ridjfe which lies to the east of the creek
ind forms (lie di\ ide bi-tween it ami l''ortyinile Creek is composed of
rrccn slates and tiilVs. which are cut b\- dikes of various kinds. In
the liottoiii of the el(
lasiu several outci'oi)s 'iiid prospci't lioles si
low
jivtiy or lilack shale, and sometimes impure coal. 'IMiis rock is evi-
dently the .same as that foiiinl on Xapolcoii Cr-ek. At otlior places
olivine-basalt forms Hie surface, and (his ro(d< is said to outcrop at
in(er\als over (he whole creek basin, and on .^'ycrs Fork to form (he
walls of a canyon Pm feet in depth.
(Irtirils. — In the travels the mosi iiromineiU rocks an; };rccn tuffs
and stales, liesidcs basalt, shale, and some coal; thert.' is iiiueh chal-
cedony, and \ eins of cinart/. showiiii;' comb si met lire; also some trran-
d (luarl/.ite-schisl, and ])leii(ifiil fragmciUs of
irbh
Chicken Crock has liitherto prodiiceil very little, (he di'Velo]iiiien(
hcini; s(ill in tlio prospecdnu' statre. The orij;inal discoverer, liob
.Alalhesoii, has prospected here for several years. Inil in general the
difijrii'.ys atlraeie<l little atlcntion until this sprinij; (is'.it;), when
nearly all the I''rankliii (iiilcli men loeatcil claims and made jircpara-
tions for winter prosjicci inj,'. On a niiiiiber of bramdies, and also on
(h.
main creek, (he pros]iecls have been very j;'o<m
The cre(dv is so
named from (lie size of (lie j;'old, which is about (hat of chicken feed
(I'orii). In apiicaranec (he jj;old isyellow a'Ul often coarse, rescmblinu'
(lia( of I<'raiiklin (iiilcli. P'rom the few prosixH'l. lioles whi(!li have
been sunk it ap|)ears(hai (heuravcls are coniparalivcly deej), bcinii
from .') to Jii feet in thickness, so that (ho niosl prosiioctiiif^ will bo
don
e in winter In burniui.
■|i^
HIANKI IN (ai.l II.
Gold in I'"ranklin (Jntcli was discovered in ISSO, and here were the
(irst j^ulcli diyginys wliic-h wore worked in United !S(a(es territory.
ii'i •■
(51 l.CII l)l(l(iIN(lS: linNKMN (in.i 11.
3;?;5
'I'lif -ulcli i> cli^iuiii '.i."i miles liy livcr I'lniii llic Vuknu, ami llo"-. iiiln
tlic Sdiilh {■'(Ilk lit' l''orl.\ mill' ('rfck In iiiilcs jilmxr I In- Noi!h Fork.
It is >^ mill's lonu'. iniil Hows in a itcin-ral f.ist«'rl> iJiiiTi ioii.
/;, ,/-,or/,-,s. 'i'lir locks lliri)iiy:li \\lii<'li lli.' ^miIcU is nil aiv .•liidly
liiifji- ami li.iiiihlcml.'-sciiists. willi iiili'rhiMl.l.Ml maihli'; llicse arc ciil
liy occasiciiial dikes.
' Xiihin nf r<ilh ij. Tim valley is hcumleil liy rueky i-iil;.'es. nl'leii on
both sides. 1ml iiKiie generally nii tlie south. Near the mouth the
eanyon-sinieluie is es| ially proiioi I. theelilVs risiiitr at limes
over ion feet rnmi Ihe water, in some plares tlieelilTs are lni.keii
down by the eiilraiiee of side irulli.'s. and ihe valle.v l.r.Mdeiis l.>eally
behind rock -ales, ihrou-h uliieh ihc-civek lireaks with an increase
of ijradi'.
In cross-section the valley is unsymmel rical. the steeper sid.' Iieinj:
on the south an<llhecic(di Mowin- iimler that stee|. hank. The lower
valley shows every <'haracter of very recent <Mitt inii, and ihc stream
in Franklin (inlch is still actively dcpcnin;;' its channel. l''or the
last :i miles it is torrential, tin' i;radc l.cini;- over so feet to the mile.
On aseendiuK the valley one ohscrvs achan-c: tli.' -rad.^ decreases
to little over IJit feet i)er mile, the valley liroadi'iis out . and the stream
no l.nmer Hows ihroii-h rock walls, hut has a channel in -ravel.
This broader vall.'y, with its .lec|M.r deposit .,f urax.d In to 1 1' feet
tliiek, is a |.art of the hi-h-level valley seen on Forlymile ( reek, in
which ero.sion has not pro-ressed to such an extent as in ih.' lower
vallev.
(,',.,,,., /,s.._The ,urav(d in this uiiper portion therclore beloiiL's to an
earlier perioil than Ihat which is worked below. Owiii.ir lo the -ical.'r
width of the vaUey and the c.inseipient dificulty of locatin^Mhe pay
streak, but little work has been dnie in the upper valley. A few chums
have been located and the paystivak has b.-n b.uiid. but livnerally
the amount of li'old .shown has not pahl for ihe tronbh- of prosi-ect m-.
and such .•laims liave Immu. al.andone.l. y\v. iMMldis's .daim-l nnles
from Ihe inoulh-islhe,,nlv(mesiluatedoi, th.- older irrav(ds, and this
isnotconsi.h.rcdamou.u-theniostvaluabhMlaimsoflhc-nlci,, Al.ov..
this point til.' civerin- of ^'lavel ap|.aivnlly thhdicus to I., b'cl. In
this prosiM'ct holes have been drivn, and s.mie pdd has been taken
,mtbvtheproc..ss.>f burniuL;-. Oiu'dialf mile above F.-hlis s .daini.
on the riitlil-hand si.h- of the rwvk. the pay streak was reaehe.l under
1-' feet of "ravel and a prospect of loc'ids toihe pan oblam.Ml. Mill
farther abov... on theopposite side, asmall prospect was alsool.tame.l,
and •! miles from the mouth a cabin was built in the early days, but
it has not be,-n oecnpie.l for !h.- last ih.ve .vars. nor has th." ^rround in
that vicinity lH...n worked. So active min.n- ..perath.ns stop at I miles
from the mouth.
Th." "ravel is uen.'rallv from s to |n feet thi.dc on the lowr c'reek,
an.l is" comi.os'ed thron-hont of -rranite, marbl,-, .,uart/.it... vein
(ii:()i.oiiv ov Tin; vikon (ioi.d distiuct, Alaska.
c|ii.iil/, aii'l Miicii-scliisi, I lie ri-iiu'iMciib
iiviiiiT ill si/i' from liowiilcrs
1 Iniil ill liicir liiimc^l (liiiiiicliT Id sin.ill pchlilcs ainl smihI. 'I'licso
riaLrnii'iils ail' siiliaii;;iiiar In aii;;'iilar, \t'iy Ni'ldnin sliowiiii; cllVcIs of
■rri'al lians|iiirlalioii, ami all' ill-a^sorlcd in rc),Mr(l losi/c 'I'licrc is
no cN i'li'iicc of si ral ideal ion cxci'iil in llic iip|)<'i- valley, wjicre in
sonic slieaiii-cMits tlicri' is a sliulili inilicalioii of lianijin;; of linci' and
coai'scr iiialciial.
Almost all of tlie rocks coniposiiii;' I lie ^'ia\ cl arc dci'ivcd from llio
drainaL'c area of ilic creek. Tlic .i,nanilc is from a
at dike which
crosses llie cvlrcnie liead of llie xallcy and runs aloiij,- bclweell
Franklin <inl
d Cliiekcii (rec
Olivine-basalt al.si
) ocelli's as
pel il lies or rounded liowldcrs, llie lar^'cslof wlijcli arc alioiil In inches
di
■ler. It. is called hv the iiiinors " {{old
and is looked
' Kold
upon as an indicaticn of jrolil, for, tlioy say. wherover th
rock" occurs in the ^I'livt'l, there thoy arc .sure lo liiid j^old in (|iiaiiti-
ties. The liasall may occur in place in the upper valley, hiihlcii
from view l>y the co\ criiij,^ of moss, but its oiitcrojis lia\e not, heou
fdiiiid. ()i! Cliickeii Creek, just across the niouiitaiii from Kraiikliii
(Jiileh, till' same rock has liccii found in place. The rock is compo.sed
■iiainly of minerals of lii;;li s|ic('ilic ura\ity (olivine .')..'!.'!, a uj^ite ■'! -f,
hoi'iildcndc I'.'.i), and is of much iri'cater spceilic ^rravily (over •'!) than
any of the quart /.-schists or iiiarhles '• liicli make up the rest of tlic
this account it is more closely associated with the },^)ld.
•avel :
The pay streak is ifcncrally thin, sc
ireci\' ever over
feel, thick,
and in maii\ cases the uravel itself is entirely barren. In many of
I'd-roek
the claims tin'
lid is taken out from irrci^ulurities in tl
surface, very little beinu: derixed from the irravel. Such is the case
on I'c^ar.son's claim. I mile above the mouth, where the ovcrlyint; bar-
ren f^ravcl is III feet thick. .Much coarse pild has also been taken out.
ill the bed of the stream, lia\in{; been washed out of the eravels and
deposited under a natural rillle.
On Feddis"s
111 there is in the bed of llie creek a
which \aries in a short dislance fi
quartz vein
iiiclii
■J feet in tliickne^
This vein is in mica-.schist and is parallel to the schistosity, strikiiij;
acre
iss the creek and diiipiiiu; u]isti
.Aluch coarse ijold has be(>n
taken out of the ril11(> just below this \'ein, and .some crvslallized
■iilver.
The miner was if^noraiit of the value of 11
often thrown away pieces found in his s
lui(
alter, and had
hich
but one specimen which
had iircscrved was not at all worn ami had evidentlv not beei
lie
carried tar.
ilso been lo
.V few inches abo\'e tin
quart/, vein mentioned {{old lias
und
in les.ser quantities
Th
lose connection of I he ^old
and native silver with 1he(|iiart/ M-iii siiirjrcsts that the vein itself has
yiehled these metals, althouirh no free yold was seen in the present
oulcroppiii};.
The ;;old is coarse and ani,'ulai', and often has iiartielos of (juartz
adherinjr tti it, showinj; its orij^in. Small nufiucts are common, and
(in. Ill nii.i.iM.s: nai'OI.i ^N <■|;^•.^K.
:;3:
11ici-c i^ xiTvlilllc li I- lliiiir L'liiil. I'l'iiii l-'fiiiiU,liri «;ul<-li h!iv««
hcc'ii liilsi' ii ilic \\\i> liiiirc-.! iMi,i;;r('ls iliscii\iTi'<l ill iIp- Viiki>ii •li->-
tricl. 'I'lii' lioi \\.i> IihiihI Ii\ t'iiin-;iil l»alil. in !■<''*. :.') iiiili-* alMivt-
tlic iiHPinli ill llii' mavi'l. Il «;is lliil-ii\a! sli;i|"->l. it^ l..ii;:i>M tliaiiK-I^T
■11 liiclu's, iiMil IriHii scvi'ii-i'i^litli> iiii'li 111 I iinli tliiik. Il» \\.-ii:li> «a>
lid Diiiii'i's. .Hill il WHS Willi 11 .iliiiiil "."iiiii u lien taki'ii out xf th>- ;rr<iiiii<l.
'I'lii' iirM liii-i:i'>l iiuuiii'l "a^ laki'ii mil frmii tin- iiiuiltli ..f a ■•mall
tiully oil llii' SDiltli siiji' nl' llii' \alli>. Tlii- UM- woitIi *l*:!'' at the
val<' I'l' i^l" l>i'i' iiiiiici'.
\ \|M| 1 liN I ttlJ.K
Napnlcoii Civck lliiws into tlic Sniilli I'mk of I'oitymil.- I r»-.-k on
till' ritiiit side, aliipiit •"( mill's iilmvi' l^'ialikliii (iulrli ami i' iiiil«-> 1»'!<'\v
Walker l^'mk. Il drains a cKiisidcialiU' ]iarl nf ili'- i'"^i'>n U-tw.-.-n
Walker I'nrk on llie soiitlieast and tiie Soutli Fork of Fortyiiiile
Creek nil llle West.
,S'/('//;< III' mill i/.—'Vhv links of NapDleoll (reek flow ill vharply
V-,sliai)i'il or treneliaiil milrlies. hut from f li.'ir i-oiillnfiief i|.i« ii toilic
luoutli llie valley is more U-slia|ii'd. Ilin- it i- <iit down t.. -mh.. .Vm
or f.iKI feet helowllie ^'eiieral level of I lir siirroiiiidiliir <f.illitry. \t
(ho mmitli llie valley Hat, or surfaii' of tin- i,'ravels, lia> a wi.liii .if
only alioiit '."I yards, and is liotindeil on Imili sides hy a MiilT i.f r.ni-
glonierale: fartlier up, liowever, llie valley liioadens and s«miii attains
a width of I'liii or iiiori' yards.
JJiil-rnrL-.—M the iiiiiiilliof the creek the l)<'d-ro.-k is.-.>ni:l"mer:ito.
often coarse; lint about :!iiii yards aliove the month it ;:ii.\vs rnii-r and
is iiiterliedded with occasional layers of irse sandstom- or j-'ri'- -^'
about ;iSii \arils the coniilonicialc is confoi'iiiably overlain l>y Iiik- jrrit
and .i.'ray sandsioiie. with thin layers of eoal-lat.- eoiitaiiiiii;: iiidis-
linct plant remains. Sandstone and dark elayslate now ln-i-.iiii<- the
dominant rocks, conuloiiierate oceurriiiy; only oeeasioiially in iliiii
beds.
A little more than Ihree-qnartPi's of a mile alxive thi- ii<..ntli th«-
sedimelilaries are succeeded by a speckled iilivc-i.'r.-.-n dial>;i>«-. which
is eontiiiuously exposed in the creek bed for a distanc- ..f iii..r.- than
aiinar1i'rofaiiiili'.aiid,,iiid,i;iimfrom11ii'topoL'raphy, prol>al.ly.-\t.-ii.ls
on up to within half a mile of the forks, where ••<«ni.'li»im.T5U<-. wit li
some arenaeeiius limestone, au'ain appears. A litth- nion- than a
(piarterof a mile below the forks on the north side th.- an-iia.-.i.us
limestone aiiaiii appears. Il is here soniewliat nianiniri;'.-.! and
apparently dolomi/.ed. |>robalily owinir to cniitaet nietani.irpliisiu. f«.r
close by basalt crops out in a small elilT.
Ill tlie lower iiart of the valley the sedimentarics strik.- N. -•"• K.
and dip eastward at an anjile of •■.•-.. but farther up the .•r.-.-k the
strike veers a liMle to the iiorlli and is almost at riirht an$:l«:-s to the
trend of the valley. 'I'lic iiriuciiial set of .joint plan.->. whi.-h an'
(juite promiiiem, strike X. HI W. ami dip westward at an auuK-..f >'• .
aao
(ii'.oLiiin ()|- rill. ^iK'iN cniA) hisriMcr. alaska.
■I
;!'
A >«ciiiiiil ^I'l, wllicll scenic 111 III' llir lii'>l (|c\ i'li)|icil Ileal' llic I'dplo,
trciiils at alioiit riirlil aii;,'li's to llii' liisl.
Ncai- till' iiiiiiMli 111' the Nalli'.v lln' iMuiijliiiiiiMali'. a> imifil. is cuaiM',
its <iiii>iiniciil rra;:iiit'iits laiiiriii;^' in si/c rniiii hutc u'r'aiiis iiilmwl-
<li-|-s a fiiiil in (liairii-lci'. allliiiil;,'li lln' a\<Taj:i' liianu'Icr id' tlif jifh-
lili-s is alxiilt - ini-lii's. 'I'lii- rfiiicnt is siiiccoiis ami iri'illy. lnil tlio
ri>ck ronlaiiis iin siMMinilary I'l' luartz in llic form nf \fins m- lenses.
'\'\t: |M'l»l>lcs are riiiindcil or siiliaii;riilar, rarely flat ; tlie,\- cuiisist
cliielly iir<|uarlz-|»>rplivry, a|ilili', ami utlier ijjiieous i-oeks; lilaek aiul
jrn-en slale: i^reeii ami iTi :i,\' iniail/.ile, ami vein i|iiaft/.
(,rnri Is. — ( iiiiill iim .< somevvlial imire 1 lian orilinary aeeiiiiiiilaiinii
.jllst lieluw llie I'dlks. I lie a \ eia^e I IlieU liess lit' t lie L-'raX el. Illllck. ailll
/miss I . \ erii.L; tile lieil-iiieU ill I lie llpper pari iif tlie \ illev is alimit S
feet. In I lie lower pait the lliiekiiess is ahoiil I -J feel. lieiiii.Miiiieli
{.'realer aliinir tile mirth side lliail<ili the south side, .io that the sur-
faee slope 1 if the deposit to the south is very not iee.ihle, amountllifj
to 4 or "i dejjrees. This seems to lie due to the more ia]ii<l erosion of
the north side, hy reason of the Jirealer iiisolalioii and eonsei|Ueiit
jrieati-r tlia\viiii;aml re!,'elalioii. 'I'll is act ion prodliees small landslides
ami eoniiniial soil-eieep. The ell'eet of this talus movenient is to
erowd the creek airai list the south liaiik. which in ]ilaces it umlereiils,
forminir a lirecipilous face.
A vertical seciioii of thcdelrital deposits, as shown on .\ylward's
claim, near the moiith of the cieek, consists of about S feet of moss,
liiuck, ami alluvium overlyinir ;> or t feet of K''i'vel, which in turn
rests on ciiiit'lomeralc, and farther uii 'he creek, on other sedinieii-
taries and diabase. The irravcls show little assoi'tmeiit. thoiiuh the
material ranu'es from coarse saiul to bowlders. The fraijments are
soiiietiiiK's siibaiifiular, soiiietiines well rounded and waterworn. Of
the diirerenl varieties of rock reiireseiite(l in the ,ii:ravcl, the foUowinj;
were Moled: (Juarl/.ite-schists, micaceous or sonietinies hornblcmlic;
vein itiiart/.: liornblciule-iiranitc; basic ij^'iieoiis rocks (pyro.xeiiite'/);
ajilite: cla.v-slate. often coaly; diabase; j;rits derived chiefly from
diabasii' mater'.il: and frairnieiits nf eoiitrlomcrale like the niiderlyini;;
lied-iuek.
Nearly all the ttold occurs uiiiler the gravels, after whose removal
it is found lody;ed in irreirular lissures, cracks, and cavities in the
conirlomerate.
No irold in aiiyaiiiount has thus far been found on Napoleon (reek
alxive the lirst two claims, beginiiing at the mouth of the creek, thoiiitli
the jiravels have been well prospected up as far as the forks. These
two claims areowiied and worked by Mr. Aylward, who, as early as
1>'.'.'I, foiiml irold here in [layiuj; t[Uaiitity. The two claims toirether
have an e.Ment of :.',.'i:.'ti feet from the mouth upstream, and are said
to have yielded thus far about *1 1,(100; >;l,u(i(l is reported to be about
the aggreyale amount taken out by all other miners who have pros-
.c A
48
t 1
p
n
9t-
'A
1 1^;
^q
m
M
t
; ti'
111'
Li
.
Hi!
""•'■"" 1 Gll.CfJ DIGGIVf;-: MI-SIi.N ( liKKK. .'J.'iT
poctcil (III till- 1-ii-i-k. making a total iiio.liici ion oT «]:.', nmi f,,|- ii,,'
erci'k. 'I'lif ^'olil i> liri^rlit vfllmv in c.il.ir .nul j^ said i.i 1 ( lin,'
quality.
Ml»l">.\ ( KEKK KIMlili [.
Alission (riM'k i^a iiiliiiiaiy nf tin- Yiiknii KiviTmi tlic Id't. jnio
wliii'li it lliiwsat a iiuini alnnit "ih iiiilfs liclnw I-'uilyniilc t'ri'.'k ami
ahuiit .s miles west of tin- iiit«Tiialioiial iMiiiiMJar.v .
'I'lic ti'cnd of till' i-r«-fk i> a littii- suiitli of fast. Inn \]u- hratii-lio llow
north. Thi' ilfaiiiau''- is most r<Miiaikahly oiir-siili'il, all of the tiilni-
tarics of any note. I'Xi-i'ptiiiir Twi'hi'iiiiU' (ri'i-k. 'ii'iiii; diTivcil from
the south siilr, ami llo« in;r into Mission (ri'i'k at alniiii liLrhl aiiu'li-s.
The largest of tliesi- trilHitaries, in order of a^'i'iit fioin tin- moiitli,
ari' .Viiii'rican. Wolf. Twelvi-milf. and I'otildcr creeks.
In IS'.i.'i, or earli<-r. pild was known to i-xist in tin- Mission Crci-k
distriel, Iml tiom- wa.s jM-tiially |)riHltii-ed until lati- in tin- siiiiinu'r of
IS'.iO, whi'ii a ffw riaiins iK-jran to be systeniatieally worked.
OKol.iKili AL MAI'.
On the map of Mission ( ii-'-k i I'l. XI.XIIl i the eh iff geological fea-
tures, so far as known, an- ronghly <lelincated. .\ not worthy I'l at iirc
is the broad e.xtt.'iit of tin- river gravels, whi<'h extend fr..iii the main
Mission t'reek Valley several miles to the .south. The area niiMi|iied
by these gravels is well n arkeii ioi»ogra]iliically from the more promi-
nent ridges and valleys which lie still I'ai'ther south: and it is clear
that the' channel of the niain stream was once at the e\i reine soiiihern
side of this area, and that it has worked gradually to the north, leav-
ing a w(dl-siiioothed country covi-red with gravels as evidence of its
passage.
.Most of the older riM-ks exinised in the area shown on this ma|i are
the impure sliales and tiilTs of the Hampart series. These are cut in
the iipiier part of .\merican (reek by a few dikes. ( )n the upper part
uf Mission Creek are found purer ijuartzites with some limestone.
Those have l)eeii provisionally referred, alihongh without sat islaiMorv
evidence, to the Tahkandit serit-s. and are represeiiteil as overlying
the Hampai't series. Aloiii: the main Mission Creek, from its iiioiitli
up to near the iunetion of 'I'welvemile Ci'cek. there are eonliiiiioiisly
ex])osed the conglomerates, shales, and limestones of the Mi.ssion Creek
series, 'fhis series rests in a[)p«rent unconformity botli on the Uam-
part si'ries and on the Talikandit series. Above Twelvemile Creek
are still younger Ix-ds. i-omposi-d of only partly eoiisolidaled conglom-
erates and sandstones. Tliese rocks are not folded and are only
slightly tilted, and seem to rest unconformably on all the older
formations, including the Mission Creek series.
The eros.s-seetion which a impaniesthe map is intended to illus-
trate tlie jirineiples wliich have iM-.-n siigu'csted. The Uampari i ks
are shown to be folded and to be overlain uiiconl'ormahly li.v the
is UKipL. t'T .'{
IH i
m'-M^
m
;5;!S i;EOM)(iY OF TIIK YTKOX GOI.I. DISTKIiT. ALASKA.
TiilikMiiilil I ks. wliilc ilicM' ill turn an' o\ ci-laiii iiiicciiii'cu'inalily
liv till' Mission Ci'cek nick> Tlii-x- ilirct- M-i-ics iia\r I ii luidcd
tiij^cliiiT. ami ii|.iiii llicir iipt miii->| (•(lir<-> liii' 'l"\vcl\<'iriilc beds liave
hci'ii laiil ilciwii.
'i'lic t'lilliiwini; it'|)iiil (III .Mi»iiiii «'i<M-k i> liv I'". ('. SciiradiT, and
dial nil Aiiicricaii (.'it-ck liy .1. K. Spiirr.
HKm ItllTI'iN •>*' i.ll.l HKS.
\n — lii\ I IIKKK.
\rar its muutli Mission (reck is a very rapid stn-ain of cloar wator
alioiil - Iccl deep and Jii fffi wide. .Ind^riiiLr from ilii' trravoi bars
liiiilt iiji in till' lower part of ilic \;dl<-y. it iiiu^t be a real river at liiiili
ualei'. It can be ascended with a canoe or small boat some in or 1-
miles. Siip|ilies have 1 n taken up by tlic miners on rafls as far as
the mouth of jjouldcr Cicek. tiioiij:li tlii> «a> |iidbai)ly when (lie
stream was above low- water mark.
Xiiliiri (if riilli I/. — < Kvini; to tlic di]i of the rocks and tiie one-.sidcd-
ness of tlie draina.ure, the cioseil valley or ;_mi1c]i type of topoi.ii'aphy is
not met with till (|nite near the head of the creek. The lower jiart of
the valley is o|ten to the Miiitli. tlie shtpe from the distant hills down
to the eri ■ i^ beiiij;' very ireiitle. 'I'lie north side, however, presents a
neai'lv 1 .intiniioiis bliitV or sti-ep slope, aloim the liase of which the
creek has iiilrenclied itself. This peculiar form of valley continues
in a nearly ilirect line from .Mission (reek aloiii: Twclveniile Creek as
far as observations were made.
/)V(/-ro<7,-.v. — The bed-rocks on .^^lssion (reek between the N'likon
and Twelvemile (reek beloiiir to the .Mission (reek series, and are
exposed aloiiii' till.' sleep north side of the valley. They consist essen-
lially of blai'k, jjfreeii, redilish. or brownish limestone, somelimes
arenaceous; black liirnilic coaly slates, and some brown i^ril. They
are lai'cly faulted, but are hiirhly l"ol<li'd, and often sheared and
crushed. The slaty jiorlion of the series is usually black, lliouf;li
soinetinies iireeii, and is traversed by delicate calcitt> vciniiiu'. The
coal is usually pyriliferoiis. and sometimes contains a irood deal of
sulphur. It is eominon to liiid pyrite in small i|uaiitities ihriMiudiont
Ihe scries, ami at times the rock contains seams of hematite or earlhy
linionile. .V li-fool layci' of this iron ore was observed by .Mr. (iood-
ricli in Ihe black schist and limeslom- .'! miles abo\c the mouth of the
creek.
The rocks of this series strike a little north of east and dip in !,a'H-
eral u:entl.\' north. They are well e\|Mised a little below Twelvemile
Creek; but aliout ilnii yards al. e tlie month of this creek there out-
crops siliceous schistose limestone, strikinjia little iiorlh of west and
dippinii' I't') N. There seems to be an iiucomformity between this
series and the .Mission Creek rocks, and Jiid^^inv' from the topojirajihy,
the line of contact lies in a ravine just north of the niuulh of
Twelv(>"'ile Creek.
::*!
(a'LCH liKJdlNGS: AMKUIi AN CUKI.K.
;i;{'.t
A lilll"' iiMTf lliaii liMir ,1 mill' Miiiili 111' tlic iiiuiitlidr 'ruch I'liiilc
t ri-fk. al'iiiir till- left ur wi'sl hank nt' .Mis>icin ( ri'ik. i>iciir> a I liini
iiii'l iiHicli ymiiiircr I'oniial icni, iicciiiiyiiiir tlic ]iniiiiiTi i>\' tlir \allr\
1k'1\vci-ii I'wi-h iMiiilc and Mission iM-cck-. Tin' fdi-k* ul' i lii-> lurnia-
Ti"in an- all (inly iiartiall.\ cdiisiiliclali'il. and iaMi.'r Ir litn- ^amlslnnr
ilii<>ii::li marl an<l iri'ii to coarsi n^ldiiicialc. in « liiidi •«(iiim' liii«l(iiT>
ai-<- - <!!■ niiiri- t'l'cl in dianidiT. 'Tln'rc ai'i' als" inlci>l rat ilii'd --I'ain^
.if liruwn li^inlic inalfrial. 'I'll nudonicralc i> niadf u|i o|' ^i'\ cral
vari«'tic> ul' |iclililcs. ainniiLr « liicli tliii>c nl' L:raniiiiid diarai-irr. u liiif
ijiiai-lz. and linn'sldMr arc cdnspiiMidUs. TIh' white i|narl/ i^ ladri'
r<i;i>]iii-iidns in tlic line than in the i-narsc ciiiiLi'liiMifraii'. Thc-i'
ImmK ar rlainly nnccinrnrinalilc with tlir iindfilvinu nnU- alreadx
ilocrilicd.
Olili r •jfiirils. — On the riyht liaiik nl' .Mi-.>i(in (frck. at >c\cral
|Kiiiits lii-twri'n Twch ciuiU' ami WnH cri'i-ks. iinti-rii|i> nl' ihi- Mack
(•(laly >lal(' 'if llic .Missiiiii (feck >rric^. risiiiL;' In a lr\cl nl' n nr '.' I'.'ci
abfivc ill'' |iri'>cnl Imd nl' tin- c-iTck. ari- cajiiii'd li\ a thifkni---. nl'
alxiiil ill t'iM-t of river ^'ravel. Tlii' material nf llie iira\c'l ranges frnm
verv small iii-hhles ii|> In small Imuldeis. and lliede|)nsil seems evi-
dently t(i ha\e lieeii laid dnwii uheii the ereek llnued at a higher
level tliaii lin\\ . Whether tliesi' nider ^laveN are ;iinil'einiis was linl
learned, .i iidirin^'. liowcx er. frnm theamininl nf i|iiait/,--eliisl wliieli
lliev <'iintain. seemingly derixi'd fmiii the liirehCreek nr |-'nrt,\ mile
scries, lliev pnilialily earr.\ at least snine ;^(ild.
Yiiiiiuii r (/i-'iri Is.- -'\'\\v ynnnii'er irra\els. niw dis]i iseil in ii-rei:ular
liars and riiiarian de|iiisits Ifnni 1 In ."i ni' i'. feet in tlpekness almiir
llie presi-nt lied of the creek, are made np in varyiiiir prnpnri inns nf
liiaterials derived frnm all the aliii\ e-nnled lied-rn(d<s observed within
tlie valli-y. as well as frnm the nlder gravels. Tlieie are also some
].ehliles of i-riieous rocks, which w(>re not found in place and which
prnlialily occur farther up in the heads of the ■rnlehcs Inward the
divide>. 'I'hese iiravel deposits aic t liird;er and liner in the lower part
of the valley, while ill the middle and upper jiart they are rather
i-oai-se. and in the ^mUc-Iics consist larLrelx' of liowlders.
.Ml alonir Mission (feck and its liranches the travels have lieeii
found liy prospect i Hi.' to carry .i:'!!!!!. At the time n''\isit (.Vuirust,
is'.ic.) some work was lieiiii;' done on 'rwehemile (feck and son n
r.oulder (reek, hut the only diirj^dnirs known to yield yold in payinir
ijuantitv were on .Vmericaii I'reek. ahout 1 l' miles ahove its mouth.
\\n,UM AN I HKt;U.
/,'. ,/.rv,r/,-.v.— Ameriean Creek is a hranch of Mission treek and (lows
into the latter stream a short distance ahove its mouth. .\hnu( :i
miles ahnxe the pnint of .junction }.'ray shales, wlneli carry seams
of coal and which helon;; lo the .Mission (feck series, chauL'e to uni-
form i:rav-hlue sandy limestone or impure line--iaiiied i|uartzile.
whieli hecomo iicai-ly iila<d< or iri nisli. and often, on account of
1 ;
V
(
3 n
. *y
y4() GEOLOfiV OF THE YUKON (iOLD DISTRICT, ALASKA. >
wcailicriiifi, l)r()\vn. At llic Ippci Caiiyoii on Aiiu'rieiiu {'reck tliere
(iciMir, licsidt'S tlic riuai'tzitt", iaiyf masses of rock consisliuj,' chit'dy of
Sfrpciitinc and chlorite, in which an; rrajjnioiils of residual olivine.
This rock is prohably of tnfTaceous orij,'in, and both it and the asso-
ciated iiii|uire qiiartzitcs and limestones have been described nndor
tlie head of the Ham])art series.
All these rocks are jjenerally mnch jointed, and often they ac(|iiiie
locally a schistose strneture, althoufih without any remarkable devel-
opment of new minerals. Along the shear zones tliere is a fjreat deal
of silicilication, so that the rock is altered to a .jasin-roid, and alonj.?
the crevices (jiiartz veins ])arallel to the shearing planes Inne been
formed. Tliese shear /.ones aiH^ also often rusty from iron oxide
derived from the decomposition of i)vrites; and often both c<ipper and
iidii pyrites may be i"oiind disseminated through the scliistose rock or
in tlie <|uartz veins themselves.
'i'wo narrow dikes were noted Jiear the Tpjier Canyon on American
("reek, one of aplite and the other of mica-lamprophyre; botli cut
across the si-liistosity, and are evidently younger than the shearing
process.
Grarels.—h-i the upper part of American Creek the valley is nar-
row and V-shape<l, tlii' bottom often being not more than b> or I.t
feet wide. In the bottom of the gulch are fragments derived from
the dills above, nearly angular or slightly rounded in shape. These
fragments are almost exclusively of the iripure quurtzites and ser-
pen! inous tuffs which have been descrioeo, and also of the (luartz
veins which these rocks cinitain. This deposit was, wIkm'c observed,
3 or 4 feet thick, and was nearly barren, all the gold being found on
top of the bed-rock beneath.
At the time of examination only one claim liad been opened on this
creek, although considerable active i)rospecting was being done.
This claim was that of ^Fessrs. Stiles, Roberts, and JUishnell in what
is called the Upper Canyon, on account of the contraction of the
valley at this point. Here the gold was found beneath the gravel on
to]) of a zone of schistose impure (juartzite 3 or 4 feet wide. In the
ujiper part of this loo.se decomposed rock fragments of gold (jccur
abundantly, often of larg<» size. In shape tliey are generally irregu-
lar, sometimes rounded, and lie in thecrevice.s of the schist, so tlmt
the coarser pieces are picked out by hand. (Some of these have (quartz
clinging to them.
In the separation of the gravels in the sluice boxes many i)eb!)les
of magnet it«^ and Itarite are found. These are well rouiuled, but are
often of considerable size. Tliere seems to b,-* little doubt that these
minerals as well as the gold are derived from the schistose zones iu
the bed-rock.
At the tinu' of the examinati(m of this creek the first clean-ui) (i. e.,
the draining of the water from the sUiic^es and the collection of the
h
USGtOLOGICAl SURVEY
EIGHTEENTH ANNUAL REPORT PART Hi PL XLIX
MAP OF A PORTION' OF
BiRcii ckki:k
ALASKA
F'rom Truck Surveys by t'. S. Survey Party in
charRe of J. K. Spurr
S, al.'
11 -. Ill r. ^1 Mil l:^
'■• CirclfCilv
Contour Interval 500 feet
Datura : Yukon River ivt Circle City
Approximate elevation 575 feet above Sea Level
Tbc ri*cl«Hgjiivr Br--a lin ioifA iu tiiwtiol liiira Iniilrati-a X,^
tbe mluln,! diutrirt alu'Wii on ft lar^«-r if ftle on l>Ute I. ^.--^
Housi' ,• -' ^ -' An,
1^ ' JPi 'r'|i4"W'ff"i's>'
" ^MnimiiodiHniLsf '
it:':,. ^ ^,>-'- )
/ ■
J 1 '
;/1WU
-^^uio
.N
..^:>*J^
^ .~^,
H
•™"^T
m
III
i ■
■^'S
f
' !*
1
':4. ■
r
li'i'
1 ; i ■
flS
(
is i'
Lr •' 'I
SI' f 11 II.]
OUl.cii ii|(ii,iN(.s: iiiiKli I i;i I'.K.
;!11
He]iiir(il("l pilill liMil ,iu>l hciMi iMiicIc, and iln' ii'--iilis wire kJ7 jiiM-ilay
to cacli man workinjr, cir. as is (■oiniiKinly saiil in I In' ininiiiLT <ii-li-iils,
"tolln- slniv<'l."'
^fiiiiniiiilli riiiiiii/is. — ( )n AnnTicaii (rcfk niannrHilli rnnains arc
fonnd on inp of tin' ^'ravi'ls in llir ^.'niches. A fra'^'nicnt of a small
tiUik was seen hci-f.
I'.lla II ( lll'.KK hIsTlfKT.
Till' I'lircli (rccU dislri<'l lirs cut indv in AnicricMii Ici rilorv . Its
source of supply is Circle City, wliicli is situated ou 11n> Yukon alicut^
170 miles below Fortyniile I'ost. Tlie actual niininj,' <listii(t issiiu-
ated sonic tlistance to the soutti of ( irde City, at llu' licadwatii-- of
Birch Cl'cek, the (lii;i;ini;s tieinj;' reai'hed overlaml liy trail from th(>
Yukon. The (list rict includes a luimlier of ^'nhdies, all of which How
into Birch Creek, and extends over an area of Ion of I."iOs(|Uare iniles.
Tlu' aci'omiiauyini; iiiap (I'l. XM\) shows the i,'eiieral course of the
streams so far as is known, and the jreneral topo;.n'apli\- is iiicjieati'd
by cont<iurs. Tlie area occupitid by this map is shown by broken
lines on the larucr maii of the jzold t)elt.
\
In the summer of IS'.K! two half-breeds found jrolil on the bars of
l.iich Creek. Tliis diseoxcry was t'oUowed by a rush of unemployed
miners from the Fortymilo district, and a camp was established at,
Circle City. The ue.xl sprint: t;old was discovered in the ;:ulcln's.
(jExr.itAr, (ii'.oijKiY.
T the district, where active miniiiir is earrie<l on tiie chief be<l-roek
is the (|Uartzite-schist of the llirch Creek series. Tliesi; sidiists have
a semicircular strike, chaiiirinj; from cast-west in the central jiarl of
the district to northeast, in the eastern part, and to northwest in the
western jiart. The di[) is couslaiitly to the s(uilh at an aii^'le vaiyin.^
from 5° to Iiii", a\'erai:iu.n- perhaps al)out lo . This strike and dip
seem to indicate that the rocks in this district form part of a broad
anticlinal dome.
The schists (Mintaiu many veins which have been sheared with the
inclosiuiT rock. There are also frequent schistose dikes, mostly irra-
nitic lU' dioritic. A .u'reat dike of j;ranite, 'J (u- :> miles wide in jilaces,
runs across the district in an 'cast-west direction, iipi)earini; on llotr'i'in
and I'loulder creeks. It is clearly intrusive and has not been sheared.
In some places are small aplite dikes, and often <iuart/. veins are
found which arclar«eaiid ])ersistenl and sometiuu's contain feldsi)ar.
All the {Tulclics How ai first in deep valleys, but suddenly emerirc
into a iK'arly flat country, in which they have <'ut mere furrows. In
the vicinity of the hills this level rci;ion is composi'd entiridy of snban-
Kular frai^mciits of rock, forming;- detrilal accumulations 'd' unknown
■f,
m
I
m
■.it
IH2 (ii;Mi.(i(.v or Tin; vi'kon (ini.i) distuict, Alaska.
<Ii'|pIIi. siin<' iici nun-lops jiiu H'i'ii. ll luis I II i-i )iiclii( |ci 1 clscwlicre
tliiil this iliMiiliis is liiricnlial iiiiitcriiil, lii-<iii;;lil dnwii l)y tin- sircniiis
ami (li'iiKsitcd iildiii; tlic slmics of a lake wliicli t'ofiiuTly i-xislcd in
tllis 1-1'1,'ioll.
l.liM.iMOi Al. MM'.
A roii^fli !,'coio;rical iiiapn'l, I,, in itockcl ) has been made of f he iiiin-
iii;: (lisliii'l. jiiiil thi' aii'a ckvitciI liy it is shown hy dotted lines on
the ^'eiieial map of I lie I'.iieli Creek di.sti'iet (IM. \l.l\ ). On III is map
t lie coarse lake deposits are shown in tlie norl lieasl corner, and it is
to lie noted how t lie streams meander in their passa!j;e tliron;,'li this
rejrion. The ^qilcli i,'ra\cls, indicated hy separate eoioi'iiiij:, show the
areas at present lieiiii; workcil lor '^()U\: tlii' rest of the r.'},'ioii is
eo\ered chielly liy t lie liircli (feck schists, cut hy occasional dikes.
The larire yranite dike nicnt ioned alio\ e is seen cut tin;,' across lloi^'eiii
ami lioiildcr creeks.
IIKSCUICTIONS OI-- (in.cll|.;s.
Of the followinu; descriptions, llusc of IIo;;"eni, or Dead wood, (Jreon-
liorii, Indepi'iidciH'c. and .Mammoth creeks art? hy .F. I'",, Siiurr: those
of Harrison and I'la^ili- liy I'". ('. Schrader. and those of .MastiMlon,
.Mill(>r. and i'orinipine li\ 11. I!. (Joodrich.
iiik;i.\i ott hi:Ariv\ ihiii (;r[.i ji.
Rl-' I
ilou'cm (iiilch received its name from the fact that the discoverer
trie(l to hold a larire part of the richest dij;j;in,iis, lakinj,^ up separate
claims for the whole of his iiiimcroiis family, and, it is said liy some,
for lictitions peisonap's. When other miiiiMS came into the j;uk'h
ami a mectin.i,^ was held, anioni; other tliinj,'slhe iiuestion of iiaminjj;
the di^^riiiirs came up, and one miner siijiirested that. " Ilog'eni '' would
lie appropriate. This su,u-,u'est ion was not ollieially ailopted, and tho
iiami' head wood was i;i\en tlie;;ulcli as lieiiiu; nuire di^nifKMl, liut tho
oriL'inal nicknaine has persisted and aiiKiny; most tif the miners is use<l
almost i'\cliisi\ ely.
!'"//( //. — ll<i:;"eni or Deadwood (reek Hows into ('ro<iked ('re(>k and
has a total li'iiirth of aliotit i'<i miles. For about li miles from it.s
month it Mows throuirli a broad, ureiitly slopinj,', sliifhtly iiiidulatiii}:;
plain, which forms a larui' part of the valley of Crooked Creek and
.joins the broad, swampy Hats throuiih which IJirch Creek flows.
Above this it has cut a well-marked valley in the low mountains
which ri.se above the Hats. At lirst this valley is broad and shallow,
as compared with the V-shapod yiorsjes which streams have cut in the
Fortymile district ;ind els(nvlieri', but farther np it narrows aicd near
its liead assumes the ucneral form of a shallow V-shaped trough. .\t
the extreme head the dilTorenl <;ullies or pup:, wiiich unite to form
the m.-iin yuleh have c(iniparati\ ely distinct ami dee|) valleys, the
amphitheater <ir cirque not being so strongly developed as in neigh-
boring giilehes.
%
4
-r
if"
III
St/- ..
(ii'i.i n |i|iii;is(i^: 11(11, i.M 1 IMIK.
;5i;i
'rilliiU;:ll(illl ilswilulc riiin-"' tile slrc'iiMi liIlL'^ I'liiNi'lv tlif iM^lrlll
niili' (iT ils \;illc'\, wllicli it lla^ ;ili|Piirclll 1\ roril ill llilll.\ lltnli'li'iil , mi
llial lliis -.idc iisc>. \ el V >liM'|ily, wliili' I Iw ntluT >|(i|ics .nnri' uiMit ly
iiml li:i> ,1 ucU-tiijirki-il .--lii'ir 111- liM raci>, wliii'h il|l|il•all•^ llu' \alli'\'
li'Vcl at an caiTiri- Nlatrc Alxnil liallway ii|i tlii> ltiiIi'Ii, on llic rasl
side, till' ;ri'anilc licil-i k lia^ ]u-,-\\ iTiidrd xi a- m lra\ r l«n liiu'li
piiinai'li's, wliii'h >lani| iini' uii each sidi' <>( a liil>nlai\ l.mi11.\. riii-x'
liiniiacdcs liirni a ciiiisiiiiMKiiis ami ^iriUiiii: iVatnrc in iIh' liiiiiii;ia|ili\-.
and pi l)\ llic naiiK' of llir |)rad\v I |lnlli'>; and I licir (•\i>Ifnri' is
of itself snllicirnl ex idi'in-o lu ciinlniN rrl llic idea liial lid- di-lfici
lias I'Nci- iinilcrjjiunc any cxiciisivc fxlacial ion.
/,r(/,- <ii;-,iiiiiiliillniix. — TIm' uri'nliy slojiiiii,'. nndnlalin;; plain ihroMi.di
wliich llii' liiwcf pai'l of llo;:"ini ('nMd< llows i> niailr I'.p of -ulianiinlar
dl' slijrldy Worn fraunnciil-.. roiisislinu' mostly of schi'-t-and ;:n('isscs,
witli some iiranilc and vein unarl/; and tin- material show- sotni'
slinlil arfanu'i'iiKMil in lioi'i/ontal layri's. as if fi-oin tlif tIVitIs of watiT
acliiin. 'I'lic naliiri- of this material shows that it has Ween lnoiiirht
down fi'Kin the nciiihliorini;- nionntuiiis. and since ije'ie is i.\ iilmee of
nil extensive jilaeiation tiie ai;entsof t ranspoitai ion niusi have lieeii
tin' small streams wliieli llow in the j^nlelies. Tiie ei,nalile arrange-
ment and distrilintioM of this stream jrravel or torrent ial detiilusiii
the broad valley of ('l'o<il<ed Creek points to the existenr.' of a laruel'
liiidy of water. whi<di must have covered ihe whole of this liroad
valle.v at the time of the ai'dimulation of ihe .irra\(ds.
The sam arse maleiial which tills np tin' (rooked ( 're(dv \alley
t(i an unknown depth extends up the narrower and well-dctlned val-
ley of llou'eni (reek alioni :; nules alioxc its mouth, so t hal fortius
distance the valley has a lirnad ami compaiat i\ ely level bottom and
theic are no niilciops of beil-ro(di. .Miove this point are shallow
sli'eam .irravcls. with i're(|ueiil oulcrojis. These L;i-a\els an' a com-
parativ(dy thin and narrow deposit, restini; in the bottom of the
V-shaiied irni'ire tlirouudi which the stream llows,
llnl-rnrhs. rhe lirsi outcrups alii>ve the limit of walerlaid torren-
tial nuiterial are of <|uarl/.itic schist carryini; quart/, veins. ,\bove
this is a belt of .^i-anite :.' or :> miles wide, 'i'his .iri-anite is massive,
and shows no sliearini; m- other alteration, ami so far as observed
oontains no ([uart/, veins. .Miove the u'ranitc Hie rock consists of
(|iiarl/.:tic and inii'aceou..i sidiists, whiidi ai'c appan^nily in laru'e
part metaimirphosed sediments. In one place a darker, s(diist<ise,
basic rock, which was aiipaieiitly intrusive into the ipiart/ilic and
iiiiciiccous schists, was ol)serve(i.
(■,',.„,., /.s. —The ijravels wliicli overlie the iiranite aiea are eomposeil
partly "f schists ami liiieisses ami |iartly of .<,nanite. They also .-oii-
taiii abiiiiilaiit frairments of quart/, veins. The u'old which is lound
l.ere is usually line, and althoiiuh present in considerable amount,
the "ravels are nut considered so rich as those farther up 'he -iilcli
■ *■>
ell:.
;{44
(il",()|.()(iV nV TllK VI'KOX .ioLD DISCKICT, ALASKA.
1
m
"if
i ■
y
..-
If;
}i
)'
if
31 ;;iii
m
llciiri' till' ^riiiiiitc is Idokcil iipciii willi (li.slavur l)y tlio iniii<M>. tliiuiu'li
tlic liclicNl (lijijrinjrs arc s.iiil In (tvcrlic the contact of granite and
scliisl. Al tills conta<'l. liic j,'()lil is coarse, as it is in tiiL' ili;,'gings
farther up. 'i'lic most i)rolilalilc u'ravcls arc fonnd witliin a distance
of t or .■> miles from the irranile licit up tlie lmiIcIi, hut in the \ipj)er
jiarl of tliis(listan<'e tiiere arc often plai'cs in wliieli llie i;oi(l is scarce,
although in neighboring claims it may In- ])rcscnt in eonsideraltle
(juanlity. \\'hen the gold is thus unc(iually distril)Utcd 1 he gravels
arc known as "siiollcd." T'or a distance of .! or 1 miles at the \-ery
head of the gulch the grasels arc not worked.
'riiroughout this gulch the barren gi'avels wliich lie on top of the
pay gravels are coini)arativcly thin, being from :j to 7 feet thick on
the average, so that all claims which show good prospects can be
worked in the summer lime, and there is little winter drifting. On
.soiiii' of those claiiris, in the sumiricr of Is'.m;, the ilail.v products were
often as much as -2 or :! ounces of gold to each man working, or, as is
locally said, - or-'! ounces to tli(» shovel — that is, liie ipiantity of gravel
which can be shoveled by one man into the sluice bo.xes in one work-
ing <1;!y of ten hours containccl on the average 2 or :{ ounces of gold.
Where the gra\'els overlie the granite there is much of this rock
associated with the other fragments, bnt above the contact of granite
and schist tlici'c ari' only schist and fragiiieiils of \ein materia'. Th's
shows that the gravel is derived from very local sources, and that its
rotite of travel is constantly down the gulch. .Vmong the fragments
of veins ar(! many which are rusty from the de«'omposition of sul-
l)hidcs, and .some still show pyrite, and occasionally gali'Ua. Otln-rs
are remarkable for <'ontaiiMng feldspar nd.\cd with thc<[uartz gangue,
anil these veins contain pyrite in tlie same way as those consisting
ent irely of (piart/.
Ill the richesti diggings the gold is geiKM'ally coarse and greenish
yellow in color, and the shape of the grains is generally broad and
Hat, which prevents their traveling very ra[)idly. Pieces containing
gold to the value of «."> or sKI are common, and the largest nugget yet
found is said to be worth *Sl'. It is i)robable that here, as in other
gulches, the gold is chiefly associated with the i>yrite which o<M'urs
plentifidly in the ([uartz veins and disseminated through certain zones
of the scliist. These quartz veins and sheared /.ones impregnated
w\\h sulphides seem to l>e especially abundant in thi' schist near the
Contact with granite, and this locality is considered by the miners the
richest 111 the guleli. The comparative barrenness of the gravels over-
lying the granite, and the fact that tiiis rock contains, so far as
observed, no ([iiartz veins or thickly disseminated sulphides, also point
strongly to til is origin. At Hill's Koad I louse a specimen from IIog"cm
(tiilch was seen which was about fmir-liflhs (piartz, the rest being
gold wliicli formed little reticulated veins, so that when broken out it
liad a leaf-like or x)laut-like form. This form is roughly like tiiat of
n
(U i.( II i)i(!(iiNi;s: i\iPi:i'KM>KN"CK ('i;i;kk.
;ur)
all llii' ciijir-i- Licild I'diiiiil ill llii> iXiili-li, as «fll ,i> in iii..>l ul In-i-- of
tills ii'u:iiiii.
(iali'iiais I'liiiinl in sr.iall hnu lili-i> in tin' u'l'axfU ami in snialli'V
grains in tin' coin-rnliahMl dn-I uilli llii' l'i'I'I. 'Hi Malim's claim,
which is one uf the mosl inmlncl ivi" cm tlic ,i;ulcli. a laiircxcin nf
galena, which Innl part ially allcn-il ti> IcaM carlMinalc, wa- I'lum! in
the hcil-i-iick beneath 1 In- i:ia\ els. 'I'hi-. vein is said tn lie cunt iiimins.
ami an assay id' a small samiili' made in the lalMir-atuiy c)t' the SnrM'V
showed 1 I (Minces (iT sil\ cr. Small liaL meiits uf native lead lia\ i- also
l>een found in the ^navels.
«,lu;i.Ml«»uN line M.
(ireenliorii (iiileh is se|iaiated ffoni lloirum by a low n.otintaiii s|inr.
It is vefy short, and soon unites with otiiers to fuiin I'.oiihier t iiilch.
At the lime <d' visit oidsmie claim, that of Mark I.o|>.t. was workiii;,',
altiioii^di till- ^n-avels have been sliown to be comiiarati\ely i-ich in
plai't's. 'i'lie .hief liillii-ulty e\|ieiieiic.'cl here wa- the lacli <if water,
whif'h was often iiisiillicieiit to feeil the >liuces ami separate the ..'old
from tlie irraxeU.
On thisi^iilch the chaiacterof the rock is preeis(dy similar to that
of the rock on Hou'i'iii (iulcii. The ^riaiiite belt <ro>ses liowlder ( reek
below the junction of (ireeiihorii. The ;_'ravel- on (>rei-nhoin an- thin,
and the dii;-,i;in,iis ciuild easily be worked if there were a snilicieni -u|(-
plv of water. The hiru'est nnu-el I'oiind on tiie irnlch so far contains
s.M worth of ;.'<dd. In the -ravels pieces of vein .lUarl/. ha\e been
found which show fre-. iro'd linely ilisseiniliated.
IMIll'KMPl.M K t lirtk
Indel)Olidenc<' Creek is oidy a few miles loni: from its head to its
Junction with .Mastodon Crcok. IJtdow tliis point the united streams
go by the name of Mammoth Creek, and several miles farther dou n
]\lainiiioth iinites with roi'cui)iin' to form Crooked ( leek.
|-,,//, ,/, — In 1:01111 the valley of Indepemleni'e ( l-eek >l|o"> M.me dis-
tin<-t variation;, from the valleys of I'.oiilderaiid lIou'"eni. farthereasl.
From the head of Imlepeiulence the sloI)e up the divide is very steep.
and the Tiumeroiis small foeders which llow down this slope have
carve(l valleys milch less eo!isi>icuous than the corr<'sponiliiiu' f leis
of iIm' ct ks.jnsi meiilioueil. In this way the hea^l of Inde|,endeuce
Creek, as lonipared with that of Ilo-'em Creek, shows a markd tend-
ency to assume th.' form of a .-if-. tie. In cross-section Independ.'iic-e
Creek N'alley also shows some sliLrhl variations from the type repre-
sented bv the valley of ll<.:,''em Creek, for althoii-h it i-. like the
ahov-mentiom'd valley, ron-hly V-sha|)ed in -eneral ..ut lin-. the bot-
tom .if the V is more rounded. This wideiiini.' of the valley. ,in<l the
steepeiiiMi: and broadenitiLr of its head, ha . e been shown in cases
alreadv described to be chi<-t!.\ due to the elTeets of ice and -liou in
.-ut;
(iKOI.OOY OK Till". YI;K()N (iOLI) DISl'KKT, ALASKA.
. '"1
I' 'i
Wm
.si)iiiiir iinil early summer: iiiid tlie criisidu of ilicsc snow ami iccaccii-
miilatii)iis, wliicli may h iivciiiciilly Icriiicd ••aiiiiiial ^'hu-icrs," lo
<lisllti.i:iiisli tliciti from llu' iar^rcr acciimulatious wliicli aro siifliciciit
ill si/.c to willistaiiil tlic annual mcltiiij;, may lu' coiisidcrod as cliiclly
dc|icndi'iil upon tlic ai'Ii<in of ulacial waters, altliouirli llic disru[)ti\('
aclion arisiiii; from allcrnali' frce/iii;;: and lliawin;;; nnisl not be over-
looked: and even llie scorinii' ael ion of masses inovinjJTflownward over
a sleejp hillside duriiiu' llie meltini: season ina.\' l>e of no ineonsidorablo
ini|iorlanee.
When we come fo consider the cause of the comi>arativoly slijjlit
did'ereiice between IIo','"eni and Independence creeks, we not<> that
the,- run neai'ly jiaiallel ancl are at no j;reat distance a[)art, l)ut
tii.:t Independence heads in a considerably hi;:h(>r ])oi'tion of the
divid''. Wlien these creeks were exaniineil, in the month of Auiiusi,
liiere wertMMUisiderable masses of ice on the ste(>|) slopes at the heail
of Independence Ci'eek, but uoni'at the head of Iloii'em. 'i'his residual
ice was presenf not. only on Imlepemlence, but at the head of all tlie
('re(>ks which rise in this hiirher portion of the ridire suri'ouudinf^ Mas-
todon Dome.
At several points in the valley of Imlependeiu-e Creek, i)articularly
on the west .side, tli(>re are disliiict teri'aces at considerable elevations
alioveihe present stream beil. 'riiesc terraces evidiMitly niaik an
aiM'ient !o\el of the valley.
(tnrils. — The nrav<'ls are identi( in nature with tliose in other
frold-bearin.u: u'ulches, beinn' made uj) of little-worn, slii^htly assoi'ted,
an};iilar or subauiriilar frauiiients of schist and of vein <|nai't/. inter-
in initled with liner material derived from the decomposit ion ami al»ra-
sioii of these I'ocks. .\t the I imi' of \isit t he yulch w;is not WiU'ked for
several miles below the head, the chief claim workini; beinjr mdy a
sill Ml distance abo\(' the juncl ion with Mastodon (rei'k. M I his point
the aciu.il width of stream <j;ra\('ls is probably {."in feet, and the jiay
streak, which is paralhdwith the jircsent cliaunel luit on the opposite
side of the valley, is about \'^ feet wide. C'lts sliowed In feet of to])
.tfravel o\er 1 fool itf jiay dirt lyiiiif on a bed of schist. This trravel
was payiiiir faii'l\' well, altlioiu;li here, as in other jrulches, tlie lack of
water was a "leat diaw liack.
M WIMIITM 1 liDKK.
:*i
I :i :
l>elo\\ I he mouth of Independence (reek lli{> bed of Mammoth Creek
widens \('ry rapidly. .V short distance bidow this point a pay streak
lias iiecii worked on the left siib' of the \alley, some Jim feet or more
friuii the present channel of the sticam and on the oi her side of the
\alley. Farther down llie width of the ,m'a\els ^rous so yreat tiiat
local iuu: the pay streak bi'cimics very dillicult and little miniiii; has
liecn doiie. The nearly Hat bottom ijraxels become wider and wider,
iner.uiim into the bi-oail plain Ihrouuh which (rooked (reek Hows,
I^I'IIIK,]
(ai.CH I>IGGI.VGS: MA>ToIl('N i Kl KK.
;;r
ami tins iiitolli.- >till lin.a-lff tlai-<>r Hiicli Ci.'i'k. 'I'Ih' iiialiTial
wliicli loi-iiis till- t...tt..iii .»t" all tlii-><' will"- valleys i- ( >simiI iaily ili<-
same, iM-iiii: siil»aiii."i'.ar frai:iiu-iits i.f schist. <niaii/, ami v'lanitc.
often <i\iitc laiu'e aii'l jrfiicrally sIkiwIiil: very little Miiaii^cnieiit . It
is |)icilpal)le tliat ii.>rti..ii~ i.f tlii> iiialerial are siillieieiilly am i'.enms
1(1 ie|)ay working: iiii-ier favmalile eoinlitiniis. ami on a<Touiii nf the
iimiieiise e.\t4-iit nl' llie^e lo.lt.iiiis tills soiiree nf siijijily may uiiiMlay
lieediiie Very liiiiM.riaiit . At the pivseiit lime, linwevei, miiiiuK is
c'lUiied 1)11 only in the miliieroiis fet'iler jiulehes.
Mastodon Creek i> the jiioiieer in the liirrli (reek ilis,.iet. as
Franklin (iiili-li is on Fortymile. It was ilisi' ivered in IS'.ii, and
sinci' thai time ha^ l«-en w..rke<l witli irreat prolit. It is even now a
larae piodiiepi- ami shows ii-> si;rii of exhaustion. The i;Mleh is lin
miles distant from Cirole City, and is reached l..> a trail whieh crosses
the swa-upy v:illey of Bin-h and ( rooked .-reeks in a smnhwot
direction.
The moiiniains in ^.'eneial have nearly level lops, sloping' aloiiL' tlie
di]) irently toward tli- -oiith. Kv.-n the hi-host points are fioneially
cov(-i-ed with nio». and the L'ai's or holh.ws an- l.oir-y and lii.ed wiih
little ponds. I'.nt aln.ve thi^ lal.le divide are oc<-asioiial lieaks which
have received, from their rounded and prominent summits, the name
"<loiiie." There are tw.. principal peaks of this characier at the
headwaters of Uirch and Mast.Mlon .•reek>. which are namd res]
lively Mastodon Dome and Porcupine Dome. Tin- lormer has an ele-
vation of 1. iL'i' feet alHive itie>ea. a- 'Id ermiiied 1 .y aneroid harome-
ter. while the latter ri>e> s.,m..- J<-" feet hi-her. Ind.-r Maslod,.n
Domehe.i.l the watei>of (;ohl Dust and Ka-le. tluwin- .lireeily into
Kirch to the west: al-o the North Fork of Ilarrismi, which tak,-^ a
lonirer course and, with the South Fork, enters IJircli (reek i-'n mil.->
to l"iie southeast. Mast.Klon Creek aKo has its s..urce here in three
heads, an.l. llowinu' east of north for IJ miles, drains into Mammoth
Creek.
The topoirraphv of the IJahl Mountains dei„-nds to a ,ii:reat extent
upon the -eoloiric stnict.ire. As remarked above, the slope ot the
mesas is determined l.y the dip of the rocks. In addition there an-
lines of weaknev, atVopled by joint planes «lli.-h illteise.t the sehis-
tosiiv at hi'di anirles. Ahm- the^e lines frost a<-tioii l.ivaks down t he
ro.-ks and the divide is rendered unsymn.etrical. <>n the side oppo-
site to the dip .■litis are pr.«lu.-ed. so that, viewed aim,- t he St rd.e. t lie
dom.'S present a sharp, steep sloi.e toward the noiih and a lathei
frradual incline toward the ~oiilli.
\11 alon" th.- .livi.le. ind.-t-l. tin- sl-.p.-s to tin- Cr<...k.Ml Cre.-k .Iraiii-
a.r',. svstem are mu.-h steeper than towanl liiivh Creek proper. The
th,,...'f l.-rs..fthe main MaM-Hh-n (;.ek head in ampint heat rnal
.•}48
OKOLOnV OK THE YIKOX C.OIA) DI.STKICT. ALASKA.
'i
w
!
Ir;
■
W'
„i.
i ••a
ijlil
•H
liiisiiis, and arc supplied 1)y many small stn-ains ^vliicli ilow from areas
of snow, small patches of which still remained in the middle of
Au^'usl. These streams pliini^e in small cataracts over jwrpendicular
dill's and talus slo])es witii a fall of S>»> feet in the lirst mih'. At this
point the valley assumes a U-shape in cro»->cction. Three miles
from the summit another branch ciitei-s from ihexnith, its valley hein},'
comparatively broa<l at the mouth but narn.wini: suddenly in an
upstr(>am direction. The moutli of this bramh marks the farthest
extension of mininj; o[)eralions. From this jioint onward only the
waters from small ;;ullies increase the volume, and the creek (lows
with considerable itrade in a broadeniii^r valley from which the hills
rise with slojK'sof about lMi . The ••hov'liacks." or dividing s])r.rs, are
unlimbercd except ni'ar the mouth: their toi»s arc irem'rally smooth,
but arc interrupted by ledf^es.
Util-i-dcls. — The rocks are mainly micaceous quartzit<'-schists, some-
times t;iapiiitic. There aro two sets of jointing, one especially well-
imirked, forming an angle of .SD ' with the i)lancs of schistosily and
striking north-soutii; the other, less well marked, intersi-cts the .schis-
tose planes at the .same angle, but also forms with the noi'th-south set
an angle of 70°. Ity these joint plane.- the rock is split up into rough
rhombohedral blocks. The strike of the ro<-ks foi' tli<' whole length
of Maslo<lon Crci'k is across the valley, and tin- dip upstream.
Besides the ordinary quartzite-schists there- are igneous intrusi(ms
of two ]ieriods. At two j)oints on the creek is a gray schistose rock
containing "eyes" of feldspar .-ind ipiartz. This seems to l)e an
altered crystalline rock of the granit<- or diorite family, which has cut
into the associated rocks at .some time previous to the dcvelopmenti (vf
the schistosily. There is also a very acid rock, composed of (juartz
and felds[)ar, which has not shared in the s^-hisiosity. No outcroiis of
this I'oek were observed in the creek itself, but in the divide it was
often seen in small vein-like dikes seldom over ti inches in width,
which send out small apophvses into the cf)untry rock.
• Juai'tz veins are numerous throughout the whole valley. Most of
them are parallel to the '.ohistosity, and evidently, in i)arl at least,
antecedent to the shearing force, while others cut the .schistosity and
the confoi'mable veins, and so are of younger age.
(irarrlK. — The gold is very evcidy ilistributed from the mouth to
within .'! miles of theliead. The greater amoiint is found on the bed-
rock, but the gravel for an average of -i to 4 fi-et above is jiay dirt.
In some ])laces the pay streak is as thick as •■ f<M'i. and at one claim
(.'Sl' above Discovery) gold has been found in payinir <iaanlities all
through the lower l(t feel of gravel. An aveni.i:e of the i)ay on claims
22, 2;!, and 24 above ])iscover\ was for the whole pay streak 5 cents
per pan: for the portion a few inches alxive l>ed-rock, ^l to the pan.
The gravel is geiu'rally <lecp, from I'l to l.'i fei't. In the last claim
opened it is fnlly 15 feet, but from there the deiiosit thins suddenly
m
FPrBB ]
(ii'i.cii i)|ii(.iN(;s: Mii-i.r.u cm-r.K'.
until, al a •listanrr ol' -2 iiiilcs I'lmii the ilmm'. it is alinosi .•iilirdy
aliM'iit. '\'h\> lliickiu'ss makfs sliovi'liiii; inln lln' imxi'i'. cspi'iially
lianl wiirk. ami on smiu' flaiiiis tlic slmvcliiiu i^ iliim^ liy slairi'S. t 'iii'
«<'t <if iiii'U slamls at llir IihIIkiii of llic cut ami sIium'N iIm- gravel up
t<i a iilatfonn. t'fiiiii whicli amitlici- set taki's it aii<l -Iidm'Is dii'i-clly
into tlif lioxcs. Tiiis iiM|uii'('> nearly donbli' tln' iiiimiImm' ii\' men llial
an- •■niiiloyi'il in shallow iliiryinirs. Imt ilic rcsiilis liavi- paid.
TIk' mail-rial in tin- liarfcn and pay i,'ravcl licri- has thi' same ihaiac-
terastliat in other parts of this district. The bowlders arc ill a-soried,
of hical origin, and sliow little evidence of traiisportal ion. .\ mile
and a half above the month the :J feet of jiay dirt is overlain b\ t feet
of s<nid. 'I'his layer of sand is slitrhtlv stratilled. contaiiiN ■-licks, and
sliows evidence of liaviii}; been deposited in (|uiet water. it \\as
probably dciMisiteil liehind some temporary dam. Several local dif-
ferences of ilepositi<in have been noted in other places, but this is
p^'rhajisthe liest marked.
On almo-l all of the otliei' creeks the .travels are Licnerally frozen
at a short distaiwc beneath the snrface. but Mastodon forms an excep-
tion to the rnle. In driftini; and i)r(»spectinu at several points it was
found that the lowers-ravels were not fro/en even in winter.
\Mi.i.i;n c hi:kk.
Miller Creek. Hirch Crei'k district, was discovered and named by
«.». C. Miller, the same man who named Miller (reek of the Korty-
niile distri.i. In the sjirini;- of IS'.H this pi-ospectoi' did some work
here, lint afterwards strnck ont for new lields.
To^jo'/zv/y//,//.— The creek is lio miles from Ciride City, and enters
Mammoth (feck a mile ami a half below the month of .Mastodon. Its
source is under a mesa of the IJahl I.ills. :!i"i fe. t lower than the head
of Mastodon. Near it heailsthe .Miller l''ork of Katrle (reek, which
drains so\itlieast and formsa part of the draina;ic basin of I'.in-h (reek
proper, while .Miller (feck (lows northward for'.' miles into the (rooked
Creek basin, in a course parallel to that of Mastodon, and separated
fn»ni it only by a ridyre which is sleep on the soutlicast side, but has
a more -rradual sloi>e into the valley of Miller (reek. The dip of the
rcM-ks all alon^' this dividinir si)ur is sliirht and toward the southwest.
Its summit is almost flat, but is broken by north-facinir clill's iiito a
series of soutliward-slo|iiii,i:- steps or benches. .Vt the vi-ry end of the
i-idL'c the acti<in of the side jinHit'!-^- combined with the ero>i(ni of the
three streams. ;Millcr, .Mastodon, and .Mammoth, has izone so far that
a svminetrieal cone of erosion has resulted.
The valley slopes of Miller (.'reek near its mouth and for :i miles
alKJve are ditl'crent on either side. On the northwest they are com-
paratively steep, with an,i;les of about :iii , and sometimes, imne
emphatically nearer the mouth, the creek undercuts its banks, form-
iu:: bluffs of liari- rock :.' • l'."> feci lii!.di. I'lMin the southeast side,
.'),"ill (ii;i)l.()r.Y OK THK VUKuy (H)LIJ DISTUIC'T, ALASKA.
:'p'
(Ill il ilicr ,i:iriil. ilicic :s a >]i;:lii iciiari- hikI m LTcntli' nsi' (ov t'loiii
(»iic-((iiiii-t<'i' 111 iiiicciirlilli of a mill- i<> a pipiiil when' tlic hill rises
steeply. The Icrraee is rciiiiied in iri'avels. which iiave since lieeii cu),
hyihe creek neai' its iiiiiIMIi, fofniiniT a irol'ire I .") feel deip. AlollLT
llie hiwer |H(iliiiii <<( Ihe stream the valley is narrow ami V-shaped in
cross-section. Init iri'adnallv . iri asi'endinir. the sides heconie of mkhi"
e\en slope fr'orn the tops of the rid;;es to Ihe erode lied. 'l"he iriax'el
also thins out aradiially. until, at a ]ioinl -J miles from the divide, if
is almost entiiely alisent. I'mii- miles from the month a branch
enters from the southwest, whose source is in a Hat, lioi;;,'y iiiip in Ihe
l>onan/.a !>i\ide. Tiiis liraiich lias a very steep urade and Mows
lhidn;rii a V-sliap<'<l \alley fori' miles, and pay was I'ouiid on it only
within a very short distaiu-e of tlie main creek. .\\ tin' head of tho
various lii'anches of .Miller ('re<d< is the aiiipliilheal rical form already
descrilied upon other creeks, and it is here, as elsewhere, due tii tran-
sient irlacieis. the remnants of w hiidi were still visilile in the miildlc
of Aii$;ust on tlie southernmost lirancli of .Miller, alt hon^h from all
llie cithers snow had clis,ip|ieaied. 'I'iie i-iicks are tlie same as npiiil
Mastoduii — ipiart/.ite-seliists. massive and fissile, into which haxc been
int rudecl ilark y:ranite antecedent and apliles snbsei|n i totlieschis-
fosily. '{'he si rike is ireuerally northwest an<l the dip ti. i he southwest.
(Inicils. — '{"he u'T'axel, where workecl lor jrold, is u-eiierally t hit'k,
avei-auin;.' fi'om \- to l.l feet, altliouuh on the hii;hest claims it smne-
tinies decreases to S feet. The i^cild is ;;cnerall\ found throu,i;h tho
lower 4 feet, altliouirh miitdi is also found direct ly upon the bed-ro(d<.
In places the lied-rock is much de<-omiioseil ami the ;;old is found
t'lnbedded In it. The pay sti-eak is very "spotty" that is, thej^ohl
is very unevenly distributed.
Xo<daimshave been wurked very near Ilii" mouth, the reason jirol)-
alily lieiinr that much belter ifround on Mastodon ami the nioro
I'ccently di.scovered creeks has ilrawn oil' tin' (daim ownei's. Tlie
|)isco\ei"v (daiiM is located ;>' miles fro.:' tiie mouth. Here the pay
.streak was \ feet thick, ninler s feci of barren ,i;ravel, and yiidded IJO
t'cnts to the pan. \\ the time nf our visit :i men were siiovidintc into
the lioxes on tliis claim, and above Discovery :2.-| men were work inu;
up lo within I'.l miles of tin- di\iile. The area miw lieiiii; worked is
eompriseil in the middle f miles of the valley, above which is the tor-
rential portion of the stream, from which the irold-bearinn j;ravels
have been washed away.
'I"he j{old here is much liketnai found on .Mj'.slodon, occurrini;' in
sinail grains. Tliere is very little tine iruld and no larjfe nuf;j;e's.
Tito sliaiie is tiiat of Hat scales, little worn or roumled, sliowini; an
orijiin evidently not far distant.
I'MIMri'lM; iUKKK.
Porcupine ("reek is tin' true liead of ('rook(>d ("reek. One branch
rises at Porcupine Dome, whence it Hows north of east thronuh a
liroad vallev, with an average fall of loo feet per mile for !•". miles.
Oncll l>Ii.(;iNOS: I'OUrll'INK ClIKKK.
h:a
It is llicii JdiiH'il liy Maiiiiiiiiili Creek. an<l i- tlieicjit'ier kimwii .is
Crooked Cl-eek. Si\ miles aliove the JmictiiHI ciiiues ill r>(i|iall/.;i
Creek. «liieli is ■■ miles loiitr and llnws iiar.illel uitli Millei- Creek,
from w liieli it is :l miles ilislaiit. heiiiu: separateii '>.v •! tial. leil^v riilL.'e.
Tlie valleys ol' l'i.reii|piiie Creek ami its liraiieli. rioiiaii/.a. are wide,
espeiMallv Hear t lie heads, jilid the (•re(d<s are iiieandeiiiiL'. 'i'he spin s
leadiiiir Ifoui the main divide ari' n'eiierallv siiumiI Ii and i^enl le. e\i-i'|>t
fur the last ei;:htli or si \teeiil h of a mile t'rcnii the(l■e(d^. ulieii their
allude is iiiere.-ised. sometimes to r.i i . The heads of i| reeks them-
selves ai-e sleo|), ami there are lre(|Ueiit clilfs, liiit the t rue eirijiii' is
ilhsonl. Tlic mesa is |ierha|is hetler marked ii|ioii t he ili\ ide alom;
tliese lieadwalers than aii.v where else in the I'.ald Moiiulains, 'I'lie
(li|)nf the roidis is sli;;lit heie. and iTieai table tops, one of them nearly
fireiilar and a mile in diameti^r, are seen. To I he soiithwesi, alonu;
tlie dip. they slope very trradually into tiie vallex nf Hindi « yi'^'k. w liile
OH t tie other side the descent is Vel'V steep. l'"olir of I liese tallies, u il h
Hat traps l"li to I'on feet (rolled between, are crossed in u'ollli;' from
Miller (reek to roicupine Dome. ,ill reaidiliitr to a nearlv nnil'oini
altilude of aliollt l.tilin f.M'l.
Two years au'o a few men pmspected both i'oreiipine anil I'.oiiaii/.a,
hilt obtained niisatlsl'actory results, .'i cents to the pan beiiiir aboiil
the laru'esl prospect, itii a nut of the width of the valley il was
very dllVicnlt to locate the iia\- st leak, and the thickness of the ura\e|,
from 11' to lA feet, was also a hliidranec to workinu: u:rav(ds « hich did
not promise excoptioiially well. So it was soon abaniloiied and has
not been invest iuated until last summer, when one man visiteil it and
was at work at the time of oiir visit. \\ the mouth of I'.oiian/.a » 'nek
tlie section was as follows:
Sii-liiiii lit llii' iiiiiiilli iif Hiiiiiiimi Cnil:
K.'.-t
Veget!iblo iiinlil ami moss
Siinil. scniistratiticd. L'oiitaiuiii,i,' a tow iiclilil.s from t to :1
iiH-lics ill iliiimctiT
(Travel. ooiitaiiiiii,\' heavy suban.nular liowlilcrs of (iiiart/.iti
sehist .
to
llAlimsON IHKKK
IFarrisoii Cn'ek is one of the lar.iiest st I'cains of the IJircli Creek dis-
trict. It is most easily reached by trail — up Deadwood (iuldi and
thence southwest over the divide. The iipiier part of the deck
divides into two forks, of which the North Kork is the h.imer, headini:
np under Mastodon Dome, and at about 7 miles below the forks the
main stn'am (lows into or iiiiiles with Kindi ( n^ek. At the iunctioii
of these two stn'anis is I'itkas I'.ar, when', in 1m':S, uold in the HinOi
Cl-eek distfiet was tiisi discoven'd.
The lirst irold discovered on ilarrison Creek was near the head of
Konh Fork, alxnit a mile below Mastodon Dome, in ls'.i"i ( .')• 'I'll-
[I'll
m'.
itirf
■ i
;! )-
; f
.'5'iJ (ii;i»l.i)(iV OK Till', Vl'KON fioM) DISIUK'T, ALASKA.
Civck is, llic'icluiv, niic> (.r the lic'wcsl n{ tlic Ui rcll ( 'reck plil • ilit;-
Him;s. I'.cl'.iic lliv initlillc >>( Aui,'iis|. is;ii;. Iiowi-vcr, llic wliolo of the
Norlli Fork was sl.ikcil nil' in i-l;iiiiis cxtciidiiij: roiil iiiiioiisly t'nmi near
the foot of the small liiiiicrinj: ••>,da<'i('r" wliicli (Ijiiikstlic Dome down
to near I'laniiai.';ui (Jiili'li, inoic than a mil'' liclnw tlic forks.
riacor (li<i.i,niij,' on I he rrcck as a whole, iiowcvcr. is in its first slairi's.
At the tinii' of our visit tlii' tola! ihiiiiImt of men at work was -.'1.
/,V(/-/v;(/,-.s.— So faras ohsorvcil mi Harrison Crfck. the conntry rork
ovcrywiicrcisof i[Liarl/.-scliist, with talcoso. micaceous, acfinolitic, car-
boiiacM'otis, and ;:r.ii)hilic phases. From llic roundness of the j^rrains
nndc • the microscope, there .seems to lie no (hiiii)t concerning,' its .sedi-
mentary oriirin. The rock is well exposed on the ri,i;h1 liaiik just
below the forks and at intervals alonj; .Sdrlli Fork to the Dome. Its
jfcneral strike mi Il.irrison Creek is noi'lhwest and southeast, witli
dip of alioiil .'ill t> the southwest, but near the Dome, aii<l on it, the
strike is east of north.
Sliiipi of niHi I/. — The valley of Harrison Creek, anil nioi'e particu-
larly that of the North Fork, is on the whole trenchant, but iiot so
sharply as many of the other .irulclies, such as Deadwood or Ho;; "em.
Conseipieiilly, the ;;ravel deposits often widen out in the bottom of
the valley and the stream smiiel imes Hows in sc\eral ehaiinels, which
inclose ura\ el bars or small islands. 'J'lie jinps, liowever, are usually
(piite treiichaiil and of steep ^rradieiit, and nearly alwa\s heail in
a ill phi I Ilea I CIS, on \\ iiose slojies are often remnants of ulaciers or lin-
jfcrini:; masses of snowand ice, which by their melt in;; feed tliest reams.
Above the ^jreat. bend in Xm'tli Fork tlie south side of the valley is
ste(>p, while the north slofie is more ;;entle. This feature lias already
been noted in the east and west ti'endin;; ;rulclies of l''orly .Mile dis-
1ri<'t, where the dilTereiice of slo])e was attributed to insolation and
tiltiii;;. In this case, however, the attitude of the sehistosity is fax'or-
able to the development of a steep face on tli(> south, and is probalily
an iiiiportani factor. In looking eastward it is seen that the steei)
right siile of the upper portion of the valley does not conlinue along
the stream where tliis turns lu'arly at I'iglit angles and runs toward
the south, but is in direct aligiinuMit with an e.seai'i)ment or ridge
formeil by the u|)turne(l edges of schist, which climbs the divide
between Harrison and Deadwood gulches.
(7/-(nv?.v. — The gravel, so far as ol)served,consistsof material dcrive(l
solely from the (|uartz-scliist series, and the fragments are generally
coarse or subaiigiilar. This isesfiecially tru<> of the middle and ujiper
parts of the North Fork. The width of the gravel varies fi'om less
than 101) to over IJOb yards, the maximu •cui'ring usually at the
inoutlLsof the pups. Sometimes also, at the mouths of tlie jMips, usu-
ally on the lower side, e. g.,in the great lieiid of North Fork, sheets of
soliil blue ice, covering the gravels for some extent, linger throughout
the sumiuur and prevent or interfere with mining operations. The
J 'i
KriKH.)
GULCH DIOGINGS: HARRISON CRKF.K.
;;;j:{
deposits of gmvol bfupiith tliis ice are Buid to l)o tliiii, l>ut sjrciii>rally
to yield good imy.
The vortical section of the gravels varies in dilTereiit loealilies.
Four or 5 feet of gravel, overlying several feet of clay, which in turn
restson bed-rock, is probably u fail' average. iSelow tiie great, iM'nd of
\oilh l''ork no excavation has yet extended deep enough to expose a
complete section. About liiree-(iuarters of ii mile aboxc the forks,
liowcver, "> feet of gravel iiad been passed through, and the iiiineis
expected to [pass through ."> uy (1 feet more before reaching bcd-roeU.
About a mile above tiie l)eiid. wluM'c the fall of the creek is rapid. 1 he
section consists of only :i feet of gravel, resting on rotten lied-rock.
'I'his rock is a deeoin posed micaceous (|iiartz-schist, traversed by ((iiarl/,
veins, (iood eolors of gold were seen (piili^ near the surface of liie
gravel, as well as lower down; anil the yield on claim .">:! is rejiorled
to be betler than was exiiected in these thin gravels, one nugget founil
being worth •'<i'."). Fnuu a little above tiiis jHiinl up to near ihe hi'ad
of the l''ork, a <listance of about -2 miles, all sections >how ihe gi;i\el
to be underlain by several feel of yellowish-brown clay, 'i'lie clay is
tough and 1cnaci(Uis, and its stickiness is said tobeciiiitea hindrance
in the separation of the gold, which here occurs almost entirely in it.
It shows some leiidency to stratilieatiiui and often there is some (piartz
gravtd. The fact that it somewhat r<'seml>les in places line Ixiwlder-
clay, and its occurrence at oik; jpoint ;!(• feet al)o\e the level of the
stream, snggesti the i)ossibility of its being of local glacial origin,
though at present there are no glaciers in this section i>( the \alley to
which it could l)e attributed.
If of sedimentary origin, this jiortion of th^ valley must have been
temporarily occupii'd by a body of standing water in whicli the clay
was laid down. The most i)lausible \ lew for the conlineiriciit of the
water is that of a landslide dam thrown across the gulch at some nar-
row i)oin( below, though no remains of such dam were obseiveil. After
the lakelet was draineil of its water the gold-bearing gravels were
deposited above, and the gold worked its way fnuii the gravels down
into the clay.
A third view is that of residuary .soil. This seems plaiisilile encuigh
forthe clay found on the sh>pesal)ove the creek, but no such residuary
deposits have been observed elsewhere in the ISirch Creek di.strict,
and it is ditliciilt to .see how, in a gulch of its own cutting, a stream
should be able, for a stretch of -' or more miles, to deiiosit its gravcds
on residuary soil. As other claims on the gulch are opened up, fur-
ther excavations will doubtless tlirow more light on the origin of
the clay.
Source af phwt r (j<>hl—\s in the gravels of the Fortymile district,
so in those of Harrison t'reek some of the placer gold is found in
direct contact with (luartz aiul (luartz-schist, showing the country rock
of the region to be the source whence the gold has been derived. The
18 GEOL, rx 3 li3
■ f|
U'
•ti i:
>,
I
1 1
3fA GEOLOGY OF THE YIKON 0OM> DISTRICT, ALASKA.
iK'st fxaiiipli' 1)1" Kold-lM'iiriiijr qtinit/. fduinl in tlio {jravols is ii rlidin-
])(>i«lai l>li)ci< (if i|iiiirt/.-scliist,al)<)iit 1} liy^ l.y.'inrlics, fdiiiid on claim
!M, iin Nortli Vnvk, aboiil liircc-iiiiarli-is ol' a mile above tli<! forks.
On one of the larger siirfa<'i's of tills liiociv is a (iiiarl/. vein, wliicli is
richly spotted with Hakes and specks of piid, rantrin},' fnini three-
Hixtcciiths of an incli in diaiueier to mere specks, which linally become
ilivisililc to the nakeil eye.
Kafjle (reck in its uiipcr part ilividcs into ^[astodoii an<l Miller
forks. The valleys of the forks, especially in their ujipcr jiarts, are
hliarply V-shaped, their sides are I'lirrowcd by ;rullies, ami they often
head in a circpn'. .Miller I'"ork is fed from masses of perennial snow
and ice which Hank the northward slope of its lioad jnsf opposite
Maslodi.ii Ci'eek. The Kajrle ( 'reek \'allcy is nsnally jii'ecipitons on
the iiiirlh side ami ;reiitly slopiiif;' on the south, and the stream holds
to the iioilli side of tlie \ alley.
(ioid was (irst discovered on Kaj;le Creek in isii.'i, aboiil a mile and
a half below the forks, and by Aufrnst, liSlni, the entire creek from
the iiioiitli of Ka;;i(» to near the heails of .Mastodon and iMiller forks
was staked and sonic mining; actually lic;fiin. 'I'ho supplies for Kaijle
are brou;;lii in \ la ^Mastodon ("reck, and therefore Imve to be fi'eiyrhtcil
over the main dlvl<lc. In conse(|ueiice of this an e.xtra eharf^e of S or
1(1 cents a pound is made on the frei,irlitaj,n', which, with the remote-
ness of the difffilnjrs, lias r(>sulte(l in the jiayment of hljilicr wa^res on
Kaj;lc (reek, tlic rates here beini;' >*\-2 \n'V day, while in most of the
other irulches they are ^Id.
Tiic points at which claims have been best opened up arc on ,AIas-
todon l''ork, on claim No. J, .just above the forks, and on claim \o. 7,
about a mile below the forks. M the former locality some of the
ground is reported to have yieldeil xCl fo the shovid. The normal
Vertical .seclioii of the placers as shown here consists of i) to S feet of
frravcl, coar.se and tine, overlyiuf; Ii to 4 feet of clay, which is in other
places seen to be distinctly stratilicd, and therefore of sedimentary
orliriii. The clay in turn rests <ni bed-i-ock. The coarser p>ld occurs
chlelly near the top of the clay, some nuifn'cts liehiif found on its \ery
top, lieiwcen the cla\' and the ji'ravcl; and with descent into the <day
the {fold liiows (iiier and is thoroULlily embedded in it. At the other
hicality, on <'laliii No. 7 and those ad.jacent, about a mile below the
foi'ks, there is very little clay, and the j^old is said to be foun<l on and
in t!ie rotten bcd-i'ock bem'ath from 5 to S feet of f^ravel. This {lohl
is jrenerally coarse, imtr^els weijihlni; an ounce oi- more bciuf: com-
mon: and some of it contains quartz.
On the main Ka.uk' Creek the widtl, of the tlat. or fj;ravel <leposit
ranjjes from a little less than -'dO to oOO yards. The maximum width
is found a little below Discovery, wliere it somewhat e.xc'cds 500
; I,
(iULCII I)IG<iIS08: MYNOOK CKEEK.
l\'t'i
yai'ils. 'I'Ik- ih'pimit also has coiisidi-rahle breadth at thn forks. I mt
scMiii l»'n;iiis 1o iiari'MW ahiivc tliat point.
Wlii'i'csci' idiscrvt'd, tlic ;rravi'ls wen' of i|iiartz-s<*hist alij vt-in
(|iiart/ likr tile hed-rocks, whicli arc freiiiu'iilly f\|«».d.
MVNOOK ( ItF.KK KIsTKK T.
Myiiodk (i-fok ciitt'ps tlic Viikoti fniin the si»iith»»ast. in th»> I>iwer
Rniu|>ai'ts, .")ii miles licl'W \-\iv\ Ilaiidiii. Tiiis creok is rar;.i| mi tin-
(.'oast Survey eiiart tlic l<laiiai'chai';;ut Kiser. Imt is iiiiiv<-r>jiily
known in Alaska l)y tli(> naino );iven above. .\lthoii;;h this n*^oii is
a lon^j distaiiee fi'oin tlie liireh Creek district, yet it lies in th*- n<>rth-
wcst-soiitiieast-treiidinfi j;old l)elt. which includes all th»- 'listricts
tiiat liav(> been descrilx'd.
F(jui' niiles alioNc its mouth Mynook (reek divides niin t»vo
branches — M\ nook jjroperand Hunter Creek. A >Iiort di'>t;ini-i- alxtw
tliis ]ioint I. itlle Mynook Creek enters. Tlie ^.'ravels ali>ii:r lh>- main
creek are undoubtedly auriferous, liiit ouat.'couni of the width Mf the
\)ille.\' over wlioso bottom they are distriliuted the pay str»-jik isdiflitnilt
to locate. It tints happens here, as lui Kortyniile Creek and liireh
Creek, tluit little luiniui; is done alouir the main stream. and nearly all
in the V-shajied t,nilches of small tributaries. In these thebotlmii is so
narrow that the pay streak, if |)resent, c.;:) oi'dinarily l>«'ea.«.ilv loi-at>-<I.
At the time of e.xamiiuitioii t wo {,'uk'hes leadinir info Mynook Cre^-k
wore beinj; workeci l)y tlie miners and were prixUicin^ some ;roM;
tiiese are Little Mynook Creek an<l Hunter (ri-ek. The di-x-rijition
of the former is liy .1. K. Spun': that of the latter is by II. IJ. i;ooilrich.
I)1S< OVKUV.
^lynook Creek was prol)ably pi'os|)ected as early as I-^i'. biii litth*
was known of it until late in tiie sprinjr of is'.i.i. when a Hiiv^ian half-
breeil, named .lohn Mynook, prosi)ec1ed this and nei^ldiorin.:; sin-ams
aiul found coarse <;old. It was not until Is'.m;, liowever. that mining
was actually bc<;uii.
(iKNKKAl. (M;(i;.0(1Y.
Near the mouth of Mynook Creek are coiigh)iiu'rates. s;intlston<-s.
ami shales of the Keimi scries, partly firndy and partly l.-i-j-ly <-«.n-
solidated, and conlaiuin.if plant renuuns. Above thes*' r-H-k-. at an
elevation of several hundred feet atiove the river, are thick >ilt~«-.in-
taininj,'' fossils of liviu^r siH'cies. Above the silts, coverin;: ilie whole
l)lateau, are iiravels of varied orijfin, which roll down tin- sHi-p hill-
sides into the valleys. On most of Mynook Creek pn.i».-raM'l of the
tributaries which have been e.Kamined the chief !>»-il nx-k- an- the
diabases, lull's, and shales of the Hanipart series. It is prolMbie that
on the upper waters of the creek rocks of the Bireh Cr\H-k »r Forty-
luilo, or both, occur, but these portions were not seen.
ii
..;< •?
3'i6 OEOLOOY UK THK YUKON (iOI-D HISTRH'T, ALASKA.
KKSCHIITIONS OK lll'LCHES.
I.ITTI K MVMMiK I'HKKK.
VtiJlti/. — At itsjiiiiction wiili tlu' main sironiii Little MyiuMik (reek
f«<iitiiiiis j:rii\cls ill its iiultuni lor a width of l("i feet or iimrf. Imt n
short (listanoi; up tlic irul<-li tlu' >rnivfls narrow to .lO or In I'li't or
less. AlHtvf tliis li'vrl ImiIIoiii on out' side is ;,'cin'r«lly a sleep rock
wall, while oil the other a ;.'enller tains slope for 10(i feel or more, and
then a >te<-ii wall ei)rn'spiiinliiiir with that on the r)tlier side. In
general .shape this and ilie iici^'lilMirinj;;;iilehesaie likethoseof I'nrly-
milc Creek and otliir sinaiiis in the gold distriet, luiviiif,' steep, liigh,
and oficii ]ireeipitoiis walls iiielosiiii: a V-shaped valley which heads
abruptly with a sifcp wall up to the divides. In the smaller jrulchea
tlio streams How in xcritalde notches with no flood-plain whatever,
while in the larjier ones tin- valley is naliiially soiiiewhat widi-r at the
Iwttoni. The liea<ls of I hoe ^Milches on .Mynook Creek show, .so far
as noted, no 1enili'iic\' toward the aiiiphitheaier form wliieh was
ol»erve<| jit the head of ^riilchesiii Fortymile and llin-h Creek di.;-
triets, and which appeared to arise from the act ion of anninil glaciers.
Tlie difrcreiii-e is proI)ai)ly due to the fact that thc.se streams which
flow into My nook (feck head in a comparatively low jilatcaii which is
little favoralile for the jirescrvaiion of tiie accumulations of ice. while
the before-mentioned gulches head in higher mountains.
Bdl-nu-ks.—'Vhf rocks on Little Mynook are those whii-h arc typ-
ical of the Ha III part scries, consist ingchictly of clay-slates and impure
felsi»athic s.indsloiio. with much oliviiic-diahasc, apiiari'iilly inter-
bedded with the sedimentary rocks. A jioculiar type, es[ ially
noticed on .Myiiook Ci'cek altovetlic mouth of Little .Mynook ( 'reek,
is a grayish-;rreeii aphaiiitic slate, often light-green and changing in
zones to dark-rcil. Some of this roc-k is mas.sive ami some tliin-
be«JdtMl.
All the ro<?ks are -oisidcralily Jointed throughout, and in certain
pjirts these joints lii'comc set so <dose together as to constitute a shear
zone. These .shear /.> oes, and. to a less degree, the jijints and the
Ixilding jdanes, atl'ird an ea.sy aeces.s to mineralizing waters, wlioso
Work is shown by the formation of ])yrito and copper pyrite, and by
the alteration of the neighboring rock to jas]ieroid by deposition of
silica. These zones of mineralization are very common through the
lower part of Little .Mynook Creek and on the main 3Iynook Creek
alx»ve the inontli of Little ^[ynook Creek. There are also occasion-
ally veins of white, crystalline (piartz, often with comb structure.
(irnvtls. — In the bottom of Little 3Iynook Creek there lies at the
surface a deixisit of muck and vegetable material, very black and full
of i-oots. In one claim this material is S feet thick, but ordinarily it
is oidy ii foot or two. Hdow this comes loo.se, dctrital material, con-
sisting mostly of angular fragments which have slid down from the
■Pl'IIB]
oui.cH hhjoixos: i.itti.k mvnuok ( ukkk.
;{57
hillside nliovo, many of tiu'iii Wcin;; vimv liiri;<', olii'ii ,i i'imiI nr mi in
(liaiiiclci-. 'I'licsc fnifjjmfiitsart' unassiirlcil, the liiKMliii ami tin- lal•^;^<
lidwldors occiirrim; to;,'«'liii'r. Mixed wiiii ilic-.- aiiu'ular HaLrmiMils,
wliicli aro all derived fnim llie nicks of tlie l{aiu|iait >eiie.s tliat <uit-
cri)|i(iii I lie 111 11 Its above, is a variable ainoii lit of \\ell-\Noiii and r>iiiMed
smaller pebbles represenlin;; a variety of roeks, anion;: «liieli tlie ^niy
inicaeeoiis(|iiait/.ile-seliistsol" the iSireli Creek I'oiinalion are con^iiieu-
ous. Tliese rolled (Travels are most abiiiidant in I lie bed of the (ireseut
Htroain, abovo th« angular doposit.
At u iioiiit about a mile above the mouth of Little Myiiook Creektlm
total tlii('kiie>N of Iho detrital deposit is about •! feet. Tlie bed-roek
below it is so imieh disinte;;rated that it breaks into very small fra;;-
ments, and so eaii be t<irii up as easily with a pick as compact ^ravtd.
This rotten bed-rock is about I f<iot deop and contains all tliey;ohl,
none beiii;; found in the overlyin;,' gravels. Keiieatli the decomposed
material the fresher rock is a dark-;jreeii olisiiie-diabase, coniainin^t
H largo amount of pyrite and hematite.
It is evident tliat hero, as in other gold-lieariny: ;;iilches, the richest
jiay streaks occur in places where the beil-rock hasai'ipiired such pecu-
liar struelure as a conse([uenceof sheariii;,'. Joint in ir, ordisinte;;ratioii
that llie goUl ]iai'tic|es are meehanieally eollci'te(l and concent rated in
the same fashion as in the sluice boxes of tlie miners, where the con-
ccMitra'ion is elTected by means of riffles. It also is lii_dily probabh*
that the fiold is, jiartly at hsist, dei'ivcd from these shearccl and altered
zones, which are often so ricliiv iiiipre;;nated with sulphides. Tim
fact that tlu! dialiases and slates of the Uampart sericsform much the
larger part (jf the o\erlying Lrravels points to these rocks as the source
of the jfold, while the ]iresonce of the well-rounded, lessabiindant peb-
bles of the IJircli L'reek. and other formations swy;;:ests the jio.ssibility
of the derivation of part of tlie goM from these.
Gravels formed of well-rounded jiebbles of various rocks, similar
to those just described, are said to lie found all over the broad pla-
teau throujih which Mynook Creek has cut, and at various oointa
along the ^lynook Creek trail tliese have rolled ilown from the hill-
tops ab(jve.
The thickness of gi'avel in T.ittle .Mynook I'reck is ordinarily lie-
tweeu lU and I'O feet, and this Ihickncss continues to the head of the
gulch witliout a great decrease. On Tnis account the gulch is com-
monly regarded as " winter diggings," as it is not generally practica-
ble to remove the gravel from the overl,\iiig bed-rock in the summer by
shoveling. At the time of the examination onl,v one claim was being
worked on Little Myiiook Creek, that belonging to ^Ir. Langfor<L
The gold taken from this claim was moderattdy coarse and <if good
color; native copper and silver were also founil with the ii'yi\, Ijut iu
very small quantities.
V
358 GEOLOGY OF THK YL'KOy GOLD niSTRICT, ALASKA.
'■i \
I
I 1!
If I
HI-NTKU * KKKK
IIiinl.T Civck is iil)<)iit :ii1 milfs loii^'. For tlif first l.l miles, aftor
Icaviiif: 111." Iii},'iri'aiijiii:i raii.ir<'. it pursues a uortliwanl cours.- an.uii<l
the luwl of Little Mynook C"reek; llien it turns at riu'lit auL'le.s I., its
former course and flows iiortli of west.
Sliapr <;/' /v///, //.— Tlie valley is <miI into a nearly level plain, wliieli
is 4.^110 ."ilKi feet al)ove the i)reseii( stream. The two sides are dis-
similar. On the south the first descent from the ridtre-top is sharp
and in i)iaees precipitous for a vertical distance of 'MM feet; then the
slope hecomes p'ntle and there is a broad bench which ends abruptly
at the creek in a blulf of l'.'i to :!ii feet. Tin' upi>er part of this bench
is composed of ^Travel, which avera!,'cs 15 feet in thickness. The
creek flows alony; the north side of the valley the whole distance
traversed, anil on this side the bank {generally rises insliar[>. i)erpen-
dicnlar rock clilVs directly from the stream. When, however, the
chann •! bends towa.d the south, awa.v from tlic north side of the val-
ley, lie l)anks are often of ;rravel. sometimes as mindi as 1.") feci in
thickness.
Hiil-n>:ks. — Tlie bed-rock of Hunter Creek near the mouth is a
coarse, ioostdy consolidated conirlomei'atc, containing: pcjibles oT the
older formations. Tliis rock is the same as that seen alonjr the
Yukon at the mouth of .Mynook (reek. A sliort distance up Hunter
(leek the contrlonierate is succeeded by shales, lutTs. ami diabase of
the Rampart series, 'fiiese rocks are much jointed, and alonir shear-
zones are silicilicd and imprcffuated witii sulphiiles. Tln-y also i-on-
laii' oci-asional veins of ((Uartz and caleite.
(Inirds. — Tin' best-])ayiu,u: parts of the claim now lieiii;r woT-ked
liave ficnerally been founil at the southernmost parts of thi- meanders;
that is, whei'e the present stream approaches more nearly it.s old
cliannel. This is not. however, to be ict;ardcd as a strict rule, for
jjtood prospects liave been found at dilfei'cnt localities upon the nortli
niile. The i,freatesl thickness of the jji'avel is I.") fc<'t. Its |>ebblesare
not (jeiierally larije, and it bears the same <'vidences of liaviny; l)een
laid down in comparatively swift-runniiifr water as the }.'rav(ds of tlio
of her districts: and tlie sann- slight stratification and illy as.soi'led I'har-
aeler ol>fain. The jx-bbles, however, unlike tlio.se of tiie smaller
gidehes visitetl in the Fortymile and Kirch Creek ilistrict, are of dif-
ferent varieties of rocks. There is, of course, debris from the hill.s
ininn'diately adjoining the lower part of the creek, such as pebbles of
diabasic tuiVs, shale, and linn'stone, and th(>se are generally large and
snbangular; but there are also wcll-ro'.i'-i'.i d sniallei- pebbles and
bt)wlders of the typical IMrcli Creek fornmtion. i.uartzite-.schists. and
schistose granites, with vein (|uart;:.
The Mireh (Jreek series does not outcroi> in the distance travcrseil
on Hunter Creek: and tlie fact that the material derived from this
fornmtion has suffered greater abrasion than the other bowhlei-s is, in
rrr : I
fprRH.]
Gl'LCH DIii(;l\i;s: KIuXDIKK DISTUICT.
;{5!t
a iiicasurc, an iTuli'X i>( I'lirtlii'r 1 1'liiispcii'tatinii. Ai-cniiliii;,' in |irci;.|MM-t-
iirs, the l)('il-i()ck Inr many miles ui) llic xnilli liraiicli i<( IIiinliT ( tfck
is tlif sanif as that just tloscribiMl on tin' luwcr cn-fk. Imt tin- I'l'i'iiia-
tion clianjjcs iieai' tlif lifa<l. whorf the iiiDmitaiiis an iii|>iis<-il of
scliistiisc rucks. I'mspcctiiii: lias alrcaily r\ti'inli-<l to tin- lica<lwati'i>,
anil a <'crtaiii aiiioiint ut" pild lias ikm'Ii I'lmiid tin- wlmlc ilistam-''. Tin-
ijold for cacli creek lias certain I'hafacteristics ul" it^ own as to ^liape,
I'olor. ami size uliicli (listin^fuisli it l"roiii tliat ol' anoilwi- eieek so well
that an experienceil miner I'an tell at once the |>arlieiilar ;_'nleli troni
wliieii a )xiven strain lias been i'ecovcre<l. Tlie ;;eneral diarai-ler of
tlu' Hunter Creek ptlil is that of liri^rht-yellow, small, hean-shaiie'l
{Trains and nuii^ets. and these oc-nr nioie fiei|nently than imwoin
{,n-ains.
Work njion Hunter (reek lpe;:an last spriuL'. and in the -ii n-ronly
one claim — that of the discoverei — uas yielding Uohl. This claim
islocateil 11 miles above the i-oiilluence with Mynook (reek iiioper.
Below this claims aie staked aceordili^' to miner's law — ."«imi feet lonir,
covering: the iiiterxcninir area. Above the I)is<Mivery claim, also,
claims are staked cont inuously for i' miles, and some at intervals still
fart Iter up. None of ti. c. however, were lieyoml th;- tirst st aire of
piiispecting.
UTUKI: (.ll.< II DKa.IM.s.
Kl.oMilKI. nl^TKlc r.
On the Klondike and Indian rivers the L'ulche> have yielde.l .-oarso
"old in a small way for some time, but only a few men weic employed
there until the latter jiart of Auixusl. ls'.»i. w hen ' lie .(iscovery of cs[>c-
cially rich ^'ravels or. .iio {.'iilches of the Klou'liki- h-d to a rush and
the transference of most of the population of Fortymile to the new-
district. No examination of this district was ma le liy the I'niled
States <;eoloi,'ical Survi y party, but, ai-cordin;r to reports, it is likely
to be a rich pro'liicei. The rocks appear to belonfflothe schisioxj
JJirch (reek and Kortymile series, and contain abundant ipiart/. veins,
in some specimens of which free ^'old has been found.
ri'l'KlI VIKiiN.
(»n the Selwyn River, wliii-h enters the Yukon below Fort Selkirk,
coarse uold occurs, and a number of men were .•ni:a;.'ed in prospectinj;
here in the summer of IS'.nl. This river, in its lower part at least,
Hows throiifrh t!ie ancient schistose rocks, whi<-h liere. as elsewheif,
<-arry abundant fpnirtz veins.
On the east side of Lake l.ebarp', .just b.'low the head, is a small
creek which is report e<l to <'arry -oarse ^nild. and on the Lew es, .just
above Miles ( anyoTi, is Ciunmins Cn-ek, wher.' the irrav.ds have
yiidded *:i to ^'< ii 'i- «lay, while on lakes Lindeman ami U.-uneii sev-
eral streams h;ve been w.Mkc.l foi- u'old, yii-ldint' ?1.-'^" to *( per ilay.
360 GKOLOUV OF THE YIKON GOLD DISTRICT, ALASKA.
I
il
SUEVLIN CREEK.
In the lower Rainparls of tlie Yukon, besifles Mj-iiook Creek, which
has lieeu described, Shevliii Creek and a niiiu' .r of others carry coarse
yold.
TIIK K<.>YrKUK.
According to prospectors, tlie Koyukuk yields }i;old along its whole
length, and is said to have ])roduccd about ^.'iOjOOO. In places coarse
gold is found, which, according to 111 testimony of several observant
miners, is derived fioni congloinerales wiiieh are made up largely of
(juartz pel)l)les. I'hese conglomerates are associated with sandston.'S,
grits, and shales, and usually have a steep dip. Tliey generally
form the bed-rock along that pait of the Koyukuk which has b "n
prospeel<'d. ami, judging froui the note of Lieutenant Allen, they a ■•
to be referred to the Kenai series.
BAR DIGGINGS.
i
a:
.•UA.NVKI! - I' FOK.MATIOX.
Owing to the considerable grade of the gulches in the auriferous
area and to the conseiiuent swiftness of the streams which flow
thi-ougli them, it is only the coarser particles of gold which escape
being carried away. The liner particles, unless they are sheltered in
.some cspeciall\' favorable position, find theii- way fro.-i the gulches
into the larger streams. The limit as to the size of the grain wliich
is tlnis transported is variab'.e, depending upon a variety of condi-
tions, such as the strength of the current, its direction, and the nature
of the bottom over wliich the water (lows. V.iriations in these con-
ditions are constantly hapiiening in the same place. Thus heavy
rains or the mi.'itingof snows produce a largely augmented amount
of watei', and under these conditions grains of larger size will be
transjjoi'ted than in times of drought. It is a geiu^ral rul(>, however,
that the \(M'v coiirs(> materials remain behind, n<it being easily t.ans-
pctrteil, and lh(> comparatively tine particles e.scai)e and are carried to
an indetinite disiance — a distance which may be \ery roughly consid-
ered as in inv(M'se I'atio to the size (tf the jtarticle.
In tile larger streams, when the current which transports gold along
with other detrital material sutlers a decrea.se of velocity, and lience
of carrying power, some nmterial niaj' be dropped to the bottom,
while the wate- (lows on more slowly and comparatively clear. It
thus happens that in long rivers which (low through auriferous rocks
or whose feeders (low through auriferous rocks there are at in*^ .-vu'r
deposits of tine gold in gravelly accumulations. Such accumu' ■■
of detrital mat<>rial are known among th(> miners as bars, and when
surticiently rich in gold to repay woiking these are called "bar dig-
gings." Bars are formed wherever the curves of the channel are
^■1
''1^
sriiiK.]
BAB DIGGIXG8.
861
such that the currpnt flows off at a tanf:«*nt to the shore, thus in-odiu--
iiij^eiaek water ami ofteu backwater <>re<idy in the iiiinioUalt' vicMiiity
of '>Uo l)auk. Thus tli ■ nmst i-<jiunion loci for bars an> iioints imme-
diately below where a pronounced curve changes sudileiily for aiiot her.
Fifi. it— DiaKTam •■? iii>-al r;v.-r. -ti'.winir a'-'MiinuluD'Hi nf Imi-M
Sliglit concave irregularities in an otherwise straiglit channel also pro-
duct' tin- conditions neccs.s;iry for tlit-sc dc|)osi1s. sinci- such iMincax--
itie.«will not ordinarily inlluenc the course of a niodi'ratcly swift
current. Therefore experienc<-<l miners and prospectors have lit lie
difficulty in locating the iM»rtion< of the river gravels wliiih arc mo^t
": I
;{(J-J GEOLOGY OK THK, YL-KON GOLD LiISTKirT, ALASKA.
f:
I)i()l)(il)ly liohi'st ill tii)h\ after obscning tht action of tlio ciirri'nt.
Tlic accoiiipaiiyiiij.' diagram (fig. 24) .shows an ideal river witli the
si)ols\vlu'n' tlie auriferous partielesare most likely to be eoueentrated
indicated by cro8.ses.
.Afo.st of these aceumulatioiis of poM are extremely recent, as is
shown Ity their eoiiuidence witli tin- channel of the ]>re.sent stream
and llu'ir evident relation to the pivs«^nt currents. .Moreover, the
gold-bearing gravel is nearly always coufined to the actual surface
8n.l ' 'lies in thickness from '20 inches to half an inch. When the.se
bars i. ' I ])ractically worked out, and have Im-cii left untouched
for a IV. li years, it is found that they have Im-cii eiirichcil bj'
new accu.i. .'ions of gold, thus showing that th<- process is going
on, even at the jn-csent time. Such baw can Im- workr.l only in
the drier i)art of the sea.son, when the water is .so low as to expose
tliciii; ami in some cases tliey can liewdrke<l only once in a imiiihcrof
years, wlicn tlicrc is a specially dry season. In the sjiriiig and early
suiniiici' and in llie wet seasons, when the rivers arc full and liipid,
tiicsc l>ars ar vcrc<l, and it is at tliis time that iIk- i>roi'css of con-
centration of tile gold pai'ticies brouglit by tin- stream is carried on.
It is evident that, ill tiie flood-i>lains of the streams there must lie
many such aceuinulations of gold, whicli liavc been left dry by
c1 aiiges in the clianne'. In tlie richest diggings, such as the Cassiar
bar Itclow tlic mouth of the Teslin. buried bar-s have b<'eii jn-ospected
and worked to a certain I'Xteiit, Init in other places they are not
usually very [jroduclive, since tliey are by no means so easy to
locate as the actually lorming bai-s, wliich liave so evident a relation
to the present stream. In contrasting the formation of gulch dig-
gings with lliat of bar diggings tlie former may be considei'ed as
essentially residual, the <-oarse gold l-eing usually derived from neigh-
boring sources anil the fine material having iM-eii washed away, while
the bar diggings are essentially deposital. emisisting of the material
thus washed away and carried in siis|MMision by the ciirrein ni'.iii a
favorable o[iport unity for deposition is iires«-Hteil. After such depo-
sition has taken ])lace an iiicrca.se in the rapidity of the current may
extract the liner gold from these bar iliggings ami carry it on iiiilil it
can find suitable conditions for again depo>iiing it. Such a bar, from
which the finer gold lias been extracle«l, is partly residual in its
nature, although inimarily deposital, and may contain gold consider-
ably coiirser on tlie average than that from a neighlMiring bar whoi?
the current is not so rapid. The fac; Uiat the velocity of the water is
incessantly changing in any given Im-alily makes clear the com [ile.xity
of the concentration of the gold particles in these bars and also
explains tlio continual changes. In this way a given particle travels
continually, resting here and there for greater or less jieriods, and
finally lodging in a coiuiianitively permanent alxxle. The very fine
particles wliich constitute the so-called " flour golil "' are so small and
*rr««J
BAH DIGGINGS.
363
light that they arc carried fur a frrcat distance, and sonic are loiiiid
along the entire course of the streams and of oilu-r streams into
■which these flow, and it even seems hijihly probably tliat the moro
minute particles readi tlic sea, where they may be taken into solu-
tion by the sjiline \vat<'rs. It is a wcdl-known fact tliat. sea water
invariably contains a certain amount of gold and tliat such watere
have the n-rjuisite i>ower of solution.
As an exiiiuiile of the distances which fine fiold may hi' carried in
c«>n>i<l<-ralile (juantity, it may be mentioned tliat at tlie lower end of
the Yukon Flatsa pan of gravel, taken from a place wliere the current
su;rg<--sted the probability of accumulation uf heaxv material, was
wa^ll<-<l and showi-d about a liundrcil "colors," or \cr\ line Hakes of
flourgold. Thislocality wasa slioi't distance above l-'oit Hamlin, ami
above it for lumdrcds of miles tlie ri\er Hows through a very flat
•leixisit. consisting of silts anil line gi'avidsof unknown deptii. in which
no oul<-rop was seen, 'i'lie sill and gravel banks, l)einir <if soft mate-
rial, ar*' rapidly worn away and taken intu siisi>ension by the wateis
of the Yukon, an<! tliis material is deiMisited as rapidly as it is taken
up. The detritus in which this gold is found, theret'ore, .nust be
taken into suspension and dc|)ositcd many times: and yet the small
I»articles of gold persist and under favorable conditions accumulate
in «-on.«.idenible <)uantity.
HKLATION DK HAIJS To (UI.C'll KKICINi ;s.
In Alaska, as in other eounlrics where ]ilaccr niininir has been
carrie<l on, the bars of the larger streams arc generally wmked lirsl,
for these, for the reasons above stated, arc u.sually m. .e or less profit-
able ■wher«-ver tlie soui'cc of gold may lie; so in the ^ukon distrii't
the Ijars of the I-ewes, Teslin. Stewart, and olhcr laige rivers were
first «"orke<l. From this the gradual evolniioii in milling leads to
the working of the richer bars on the smaller riv(>rs. 'rhu.- the dis-
eoven' and <levolopinent of the bars on I'orlymile (reck folfowed the
workings on the larger rivers, and iircccded all gulch digtring. On
Bireli C"r<?ek, also, the first gold was discovered in thi' bars. From
these richer bars the gold is ordinarily gradually traced to its source,
and workings along tli<' gulches prove so much more iirolitable than
the l>ar mining that the latter is soon abandoned. In the suiiiiiier of
1*00 the few men workingwith cradles and sluices on Ihcbarsof T'orty-
mile ('re<-k Comprised nearly all those engaged in bar mining in the
Yukon di.strict.
'■«7
n
OriTKREXCES OK (iOI.l) IN HAKS.
Fine gvild is found widely distributcil in Alaska. All the smaller
streara.s w^iose bninches have been described as alTording gulch <lig-
gings .ilfio contain gold in their bars, licsidcs these, the larger rivers
into which they flow contain everywhere fine particles of the precious
3fi4 OEilLOGV OF THE Yl'KON GOLD DISTRKT, ALASKA.
nietai, and often these particles aecunuilate in sufficient quantity to
repay working;. Tliiis jrold has been finiinl n\oi\ii tlic whole h'ngtli of
tlu' Lewes, the Teslin. llie Hi!,' Salmon, the I'elly, the Stewart, and
the Koyukuk. Helow the jiinelion of the IVily anil the Lewes Iho
Yukon yields };old eontinuously for nearly its whole eonrse. Kveu .
the silts of tlie Yukon Flats yield |,'old in plaees, as already noted.
On White Itiver \h: Hayes reports a very small ([luintilyof line
yold, aithouj,di there were no eneouraj:ln,i; iirospeels and very lit tie
vein quartz was found. On the Kuskokwim f^old is reported by
prospectors, and also cm the Fish I{i\er, which Hows into Xortqn
Sound. On the Kowak S. 1!. .McLeneuMu' rei)orts lU'arly everywhere
coh»rs of {fold.
ANCIENT AND FOSSIL. PLACERS.
i
KLKVATKD AlKIKKHOlS (iK.WKI.S.
Besides the .•lurifei'cius irravels in the heels of the |)resent streams,
elevated <rravels of greater .•i;;e ai'e wiiles|)reail. They occur abun-
dantly on terraces at various hei{.dits aliove the present streams, and
arc even found on the i'iilij;es or divides. ( >flen th(>v are strewn o^ er
the whole surfaei- of broad elev.ited plateaus. From the extensive dis-
tribution of tlle^•■;,'ravels and from the positions in which tlicy ari often
found, it is clear that they can n«jt be ascribed entirely to river action;
and this, joined witli the evidence of recent 8ul)nierj;enee, supixn-ts
the ide.i that they are lar,.,'ely marine, or have been redistributed
by marine action, alt hon<.di those which luiike up the lovicr terraces
aloiiy:the river are probably due directly to river action, })ein{j; portions
of older beds which have be.-n left as terraces by the down-cutting of
tlie stream.
In many i)la(jes these gravels are found to be auriferous, as is to be
e.viteeted, since they are made largtdy of the gold-bearing rocks of
the Hirch Creek and Forty mile series, from whicli, under favorable cir-
cumstances, the precious tnetal must be concentrated. From these
elevated auriferous gravels, as has been suggested, some of the gold
found in the younger deposits in the l)ed.s of the present streain.s may
be derived; and, sinc<> these gravels are very widespread, they may
account in part for th(> occurrence of gold in small qinmtities in nearly
all Alaskan streams. Up to the present tiiiu- tlie.se elevated aurif-
erous gravels have not been e.Kploited for gold in any considerable
■way, but it is possible that in the future, under favorable conditions,
it may become profitable to work them.
' C'ruiav of tlio U. S. reveuiif steamer dirwiii, lX'<i, p. lUT.
PLACER DEPOSITS.
3ti5
FOSSIL PLACERS.
NAl'iiI.KOS lUK.KK.
On Xaimlenii f'n'ok, in \Uv l^'oiMyiuilc district, lli" tocks of tln'
Uiiiii|)iU't ami Forlyniili' scries arc overlain iinconl'driiialily near the
nioiitli of the creek by a scries of eonu:hiinerates, sjiiidstones, and
shales, wliieli have lieeu referred to the .Mission Creek series. The
lowest ImmI of this yoiintrcr series is ;i coarse basal eon^'lonii'rate. made
lip of frauinents ranuinti in size up to a foot in diaiiieter. These fra;;-
inents are of ipiartzite, voin-<|iiartz, gray and green slale. aplite. jior-
phyry, and other roeks derived from the ISireh Creek. I'mtyniile. and
Rampart series. The coiigloinerate dips steeply up the valley of
Xapoleon Cri'ck. so that a short distance I'artlier up it is overlain by
sandstones, grils, shales. ;iiid limestones. In and iiiiniediaicly belnw
the l)elt oc('lipie<l by 1 lie l)asal conglomerate the present gra\eNiu
the Ix'd of liie creek are rich in jdacer g<pld: but ;ibo\(> tliis compaia-
tively narrow zoiu' they arc entirely liarrcn. and below it they are
very poor. It is probable, therefore, that the gold isderiveij from the
basal conglomerate; and from tiie fact thai this euiigloineraie is cinii-
posed of fragments of the older aiiriferotis rocks it seems ]nobalile
that the gold from these rotdvs has been concei.lraied mccliaiii' ally.
In other words, we have he:-e an ancient gra\ei liccj in wiiich gold,
derived from the erosion of auriferous rocks, was I'onccntrated. Tliis
gravel has li(<'n consolidaled into a hard conglomerate and has been
biirie(l for an iTiimense ])eriod of time biMiealh a gr(>at thickness of
later deposits. It may therefore be called a fossil ]ilacer, the term
"placer" being nnderst 1 to include both ri\er and bea<'h ilei)osits;
indeed, in this case it seems probable that, the material may have
been a beach deposit.
THE KOYtKIK.
According to ])rospectors, gold occurs all along the Koyiikiik. The
chief producing localil.v is said to have been about .'ioo miles above
the mouth, where; the rocks are conglomerates, sandstones, grits, and
shales, dipping steeply; tliis is also in accord with the brief note
matlo by Lieutenant Allen; and from tlie.se descriptions it aiipears
probable that this conglomeratic series is jiart of the Iveiiai series.
The gold is sai<l to be derived from tlie conglomerates, which contain
pebbles of dilTei'cnt rocks, especially of rolled (|iiartz. If this is the
ease, we have probably here also fossil i)lacers or aiK'ienl auriferous
gravt'ls, whose formation dates back to the Ivtcene or Keiiai periocl,
and which have subse(iuently becMi buried, and oiil.\ expose! '.gain
in consecpience of great folding and profound erosion.
liiScl.lSIoN.
From the evidence furnished by conglomerates everywhere through-
out this region, we know llial the gold-bearing ro.'ks, such as those of
II
366 (JEOLOGY OF THK YIJKON (!()I.I> DISTKICT, AL\SkA.
flu* Fortyiiiili- iiii'l ISiivIi ( iv.-k scries, were expo(MJ«l to iifnosplieric
(M-osi.in since the l)e;;imiiiit,' «( the <lci><>sili()ii "f the Miswioii Creek
series, and jn-ohiihly l.et'ore; and this erosion must have yone on ivt
intervals ever since. l)iirinf,'ali tiiis period tin- jinx'esses of -•onren-
Iration went on in rivers, on l>eacln's, and in other phice.s, ])rccisel}-
a.sat the present (hiy. so tiiat portions ricli in jjoiii, or jilaeers, must
(.'ontinually have l)een forming'. At limes of extremely rapid erosi(ni
and do|)osition, moreover, such as tlial under whicli tlie Kenai con-
;;h)nieratit' series was deiiosiled, coarse jrravels suital)le for the acen-
nuilation of -.'old were rai)iilly laid down. It is reasonable to suppos<',
therefore, thai these auriferous conirlomerates or fossil jjlacers will in
future Ite found to have a wide dislrlhulion and may become of con-
siderable imporlani'e from a commercial slandi)oinl.
METALS OTHKR THAN GOLD IN PLACERS.
All the i^old produced in Alaska is alloyol with a certain small
amount of silver. I'.esidcs this. i)ure native silver is freiiiiently found,
alouf; with f;old, in the materials concentrated in the placer workiu<;s,
^'onerally in small rounded or irre^'idar nuggets, although occasion-
ally, as at one i)lace in Franklin Gulch, well erystallizeil. Native lead
occurs in small nnggcis on llog'cm or Deadwood t'reek. and nuggets
of gold which come from this gnlch sometimes contain native lead in
small bits. Native copi>er, in small rounded nuggets, has been found
.on Little .Mxiiook and Hunter creeks.
Platinum has frequently l)cen found in the 'tiikou ilistrict, chiefly
in the iliggings in the ujjper ])art of the Yukon drainage system. On
Twelvemile bar, which is li' miles below the liig Salmon Uiver, on
the Yukon, the yield in platinum is said to lia\c been .' or :! ounces
to each 1(1 or 1:.' ounces of gold: 'the metal, liowexcr, was not saved,
since the miners were ignorant of its value.
m
ORIGIN OF PLACER GOLD OF YUKON DISTRICT.
The tiny Hakes or coIot's of gold which arc found so widely distrib-
uted in the sands and gravels of streams are capable of being carried
enormous distances wittiont being destroyed, and are many times
deposited and again taken into susi)en.sion by changes of current.
Thus it hapi)cns that line or flour gold in small ((uantities may be
found along the entiri' cour.se of most of the rivers in Alaska. On
account of this indestructibility aid facility of f ransi)orfatioii, fine
gold atTords no adequate inde.K of the source from which it is derived.
As the gold becomes more abundant and coars(>, however, it is clear
that the source is being nearcd. Thus on Kortymile t'reek and on
IJircli (.'reek the bars on the main streams were richer than the bars
on the Yukon, into which these streams flow. Tn this way pros[)ect-
ors find continually i-icher accumulations, until, finally, in certaiu
4
OHICilN OK TlIK IM.ACEK (lOl.D.
367
jrul<-lifs wlinso wat.Ms run iiih. th.. river on whidi ihi- Imrs liav.- \h;-u
Iircvidiisly wi.rkcd. ^oM is fouiul wliifh is fairly i-..arsc ami in .-cusi,!.
orahk" (|uaiitily. In Iho.si' jiulclics nujtKots an- I'.niiiil, and t'ra;riiii'iits
of <|uart/, and jfold mixed. It is ovidcnt llial llicsc pla.-cs ar.' m-an-st
tlu' Iriic sourc' of the };old, and tliat from Ikmv liavf 1 n .Icrivcd
11h' liner and rarer particles wliich occur in the liars oi llie lar;:er
streams, aud also tlie still liner and rarer particles in tlic rivers into
whieli tliese streams eini>ty. Therefore, in im|uirinjr as to the source
of ])laccr ,!,'old we may jiass over the widcspnsid line or (lourtjold in
the -.'rcat rivers and also the bar di,i:f;in{;s in the tributary sln-ams,
and contine our study to the i,'ulcli di,irjrin;:s.
l>i:iilVATt(>S- ()|- (,(11,1) KltdM ( KliT.MN 1!( M K l-( il!M A I 1( iNS.
nisTuim rioN ok um h (iri.iiiKs with |(|-fi;i(i-..\( k to (M:nic
.11 M, -Tlili TI'ltK.
The Kirch Creek and the l^'ortymilc (list ricts arc. up to this lime
tlic lichest, placer dij,'irinjrs in the ^■ukoll rcirioli, allhoui;li llic new
tlij-'uniirs on the Klondike aud Indian rivers promise well. Tlicsc all
lie in the rocks of JJirch Creek and the l"(irtyiiiilc series, of the
smaller ijulch-mininifdistricts, American (reek and .Mynook ( re(d< are
the only ones which have been ]>roductive hen-toforc, and these run
tliroiiy;!! the rocks of the Uampart series. All the districts lie in a
dctinite /.one or b(dt, which has a northwest and southeast trend and
c(irres[)(in(ls with the /one .(ccupicd by the exposures of the oldest
rocks alonu; I iic eroded Yukon ,ir(>anlicline. Alo-iir this /one we ma\'
say that the richest difjtfin^s haxc )i(>en found in areas occupied by
the Mireh Creek series, and also some r'cli uulchcs in the I'ortymile
rocks, and that g(dd in payiiij,' (plant it ies has been found at times in
jiulches lyin;,' in the rocks of the Maiiipart scries, while iriilchcs which
cut other formations have almost iinariably proved barren. If,
besides the jruUdi di,Hf,'in,u;s, we take into consideration the richest bar
difTfj^iufrs tiUmg the Yukon, Stewart, Hij; Salmon, and other rivers, we
see that the alii;nment of the rich jjold district in a northwest and a
southeast direct ion, "corresiiondinji' with the belt of the older schistose
roeks, is still more strikinj;.
The .su,u:,!J:<'stions olTcred as to th(> occurrence of },'ol(l, which are
derived from the correspondence al)ove noted, are corroborated by
detaile(l sliidv in the u:ulches theiiisclves.
(ai.( IIKS IN ltlU( II ( HKKK ROCKS.
^Miller, (ilacier, I'oker, and Davis creeks in lh(> Fortymile district,
the entire IJirch Creek district, and also jirobably nujst of the Indian
and Klondike ,u:ulches, all have cliaractcis so nearly identical that they
may be described together. All these How entirely throuffh the (|uart/.-
ite-schists of the Hircli Creek series. These schists cv(>rvwlierc con-
tain numerous (piart/ veins, and are cut by occasional dikes, chiefly
.'568 CEOLOfJY OF THE YUKON GOLD DISTUICT, ALASKA.
T
I:
1 1 '
.11
It ' •!
i
ol ^rniiiitf ur (linrito, which aro womcliinea of liirge size. In all liio
>:iilchi-s tiic jjriivclHnn'cntirt'iy iiiadi' iiixpf fragrnontsof vovk identical
with that found in placo on Iho ncif;hli<)rin« hillsides. These f;nivol.s
vary in thickness np to alioiil 2") feet, frenerally, altliouyh not always,
incieasii.i; with the distance from the liead of tlie gulch; in them the
schist is in iiiiite lai-ge, flat fragments, often witli ragged outline, and
llie (i.tartz is in bowlders of varying size. Tho schi.st fragments all
lie Hat : but that wator action has been slight is shown bylhe fact that
nii.\e<I with the large fragments is sand, and even fine soil, which tlio
current has not been powerful enough to, separate. The schist, more-
over, is so brittle that if it were carried far it could not long remain
in the large, (lat fragments in which A is found. The nuiterial, th(;re-
fore. is essentially a talus derived from tin; steep walls of the gulch
valley, and lips talus lias been sliglilly rearranged by water, but not
sutlicienlly to bring abdiil any great changes. As a general rule tin*
irialei'ial and ari'angement of tho gravels from top to bottom are tlio
.same. In son f the >rulclies. however, there ar(< slight ditl'er micos,
wliich are gemially found t<> be local. Thus, un (ilacii'r. I'oker, and
Davis creeks, in tlie Fortymile district, the gravels have a tendency
to be liner at the liottom than at the top; and on Ilarri.son and Kaglo
creeks, in the Mirch Creek district, there is a <loposit of clay boneatli
the gravels. In other partsof Kagle (reek, howevei', the clay is lack-
ing, and on pai'ts of .Mastodon I'reek, in the .same district, the gravels
are tinei'al the top; while on Poi-cupineCr-eek a Ixnl of sand was found
to bethe niipermost layer'. These variations, thcrefoi'c, seem to i)oiiit
to no widespread var'iations in the conditions un<lcr which the thin
gi'a\els accumulated, and tho occasional differences are i)r(jbably due
to local and ternpor-ar-y cati.sos.
The bed-i'ock underlying the gravels is always tho quartzito-schist
of the l>ir-ch Cr'cck series, containing veins of (iuartz. This schist is
disintegi'ated, <leeornposed. and I'cddeiied from oxidati(<n for a short
distance below the surface, this distance ranging from a few inches
to -2 or.") feet. As is ordinarily the case, the decomposition is attended
by a shr'inking of ih; i-uck, due to the loss of ceitaln comiroiients by
the leaching of the sur'fai'c water's; and in conseciuetrce tho r'ock
becoirrcs linely cr'acked, jointed, and poj'ous for srtme distatrce down.
Although as a rule the gravels rest directly u])oir this moi'o or less
alter'ed schist, yet orr llar'i'ison and Eagle creeks, as noted, is a layer
of clay se\er'al feet in thickness between the gi'avels aiid the schist.
This clay is .sometimes dirty and pebbly, sometimes clean and well
str-atilied. It is, however, only a local deposit, since it is not found
irr neighbor'ing gulches, ami. indeed, irot in the wiiole of Eagle (iulch,
foron i)ai'ls of this gulch the gi'avels r'cst uiron the clay, and in others
directly irpon the schist.
In regar'd to tlie distribution of gold in tliest^ dejiosits, it is a gon-
er-al riih'. to wliich there ar-e few, if any, r'cal e.vceptioiis, that the gold
Si
mil
HI'IKK]
OUKilN OK THr. I'lAfKU (MID.
36;i
iM I'omid ill y:i'i';itfsi aim Hint at lliccxlri- Iiuiioiii <>( thf ;rrikvt>I»itr al
tlicsiirl'ai'i' 1)1' t lie uiiili'ilxiii^' iiialcrial. < Micii i lu' ;:iuv»'N tlifiiis<>Iri-!t
ar.' ciitiicly Iparicii, lull iiMiall.\- llicy ari' u'lild-lx-ariiiu' (»r s«.iii»- ili*.
taiH'i' aliciM' I lie hill loin, tin- anion nt of ^'old ln'comiii;r l.s* inuani f!n»
toll, iiiilil il ^'idws so f<U>i\i\ tlial llic ;:ra\cls ari' liol worth wa>hin::.
'I'ho portiim wliidi conlaiiis ;;olil in Milllcii'iil qiianiiiy to v>\my wurk-
iiiy: under tin; present condi I ions is railed jiay din. 1 1 iiiiisi }h. lN>rnt>
in mind, however, tliat the present conditions of wurkiiiir are vrv
expensive, and that eeilMin gravels whieii are eoiisidereil worthU-v»at
tlio present time would iindoiihteilly, w ilh cheaper inetiiods. j.n.ve
profilable. I'lider the present eoiidilioiis liie a\ era^'e thicktierss, ,,f
pay 1,'ravels is jierliaiis iiol morelh.in J feet, tiioiiudi rarely ;i>. imn-li
as li' feet, wliile the overlyiiii^ ;,na\els a\eraire S uv pi feet and liavt?
il niaxiinuin tliickness of alioui l'."i t'eel. itelou a depih of -Jt'i fw-l
praclieally no workiiij,'s have 1 ii uiideiiaUeii. alliioni;ii in eertatn
parts of tlie country there are mucli deepei' Lrravels wliiidi may in
future lie explored and worked.
( iold is foil ml not only in the iriax els alio\ e the siirfai f tin- -M-hisf.
but also in Ihi' schist itself, in some cases for J or ;) I'eet il.iw n. aii<l in
otliers for only an iiudi or less. The amount of fjold irener.-iUy i,'ri>ws
less as the distance from the ^;llrfaee of the schist increases, and as a
fj:eiii'ral rule it i.s only that portion of tin.' rock which has been broken
up ljy disinte,i,'rati(m and decoiiiposition whiidi is j,'old-beariri;r at all,
till' fresh rock beneatli beinjr barren. The depth to which irold is
found ill tlie bed-riKdc therefore de[ieiids upon the depih to uhii-h
disintejcration has penetrated.
On Harrison and Eaglo creeks, where the gravels are underlain l»y
clay, ijold occurs chielly at the very top of the clay. Here tlie miiTirt-ts
are generally found, and the coarsest gokl. Above the top of ilu-
elaythe gravels are gold-bearing for a varying distance up; and U'I>>w
the top the clay itself contaius a g''eat deal of gold, which, however.
grows finer and less in (luantity as the distance from the top iui-r»Ms»~i.
The same occiirrenco of gold is reported in places on Mastmlon (n-t-k.
In these places the bed-rock below the clay is practically barren.
It follows from what has been said concerning the locus of the con-
centratiiui of gold thatthe particle.s of this metal ai' < -i ve<l from the
gravcds, in the bottom of which they an,' coiKM'iilraii-i by r»>ason «>f
their greater specific gravity. The fact that in places the whole thick-
ness of gravels is suthcientlj' auriferous to re[tay working shows that
the gold can not have accumulated in any special period in the «le|x»-
sition of the gravtds; while other localities, in which the pay gravel.*
become thinner and thinner and are always at the very bottom of tlie
deposit, show various stages in the concentration, until in manyca.-*-*
most of the gold is found at the extreme bottom of the gravels, restinir
on the underlying material. The fact that the pay streak when thin
is usually so ricli as to make it as well worth working as the thicker
18 GEOL, PT 3 liJ:
370 fiKOLOOY OK THE VIKOV (iOI.U KISTKirT. ALASKA.
Iiiit iHxitT irravclr*, also points to this coiKciiiiatiii;.' action. Since
iK-arly <-v<Tvwln'n"tlu' iM-d-rocks wliioli niulnlir the ;;ia\fl.s aisocariy
piM.xinii'tinics in i:r<'at<r i|Uantit.\ tliaii tlii' uiav«'lstluMns»'lves, some
have iMM-n Icil to tin- liclicf that tin' u'olil was oriirinally picsciit in tlip
r<M'k: lint that tliis is nut true is siiown In (he fart that wln-n tin- ImmI
pM-k is overlain hy day, as on llaiTisou ( nik, ilic ;,'i)lil has Ix'cn cun-
•••■ntrai<-<l in tin- sticky ami inipcrnicahlc lilankct ami the heil-rock is
• larren. Moreover, in cases « licic the heil flick cai'iics ^old, theoccnr-
r»-nee of nietal is eontineil to those jiarts which have heen i-enilere<l
niiK-li joint! •] an<l i.orous liy siirfi Iisintej:i'at ion, ami the schi>t a
.•'liorl .le^tanee Ik'Iow the surface is liarren. It is thnseviilent that
tlie<|eeoiii]H»4-il schist ha> acted n Iiatiically to eati'li tlie particles of
;:old .vhidi li.ne wrrkcd down fi tl \ei'lyili^' Lcravcls and which
have full nil a jHTnianent safe lod;:inent in the cracks and Joints of
the nx-k. and that the schist in this operat ion has |)layed the saini'
I«irt a-» tin' clay al>o\e noted, or as would any other material snlli-
••ieutly jM-ni'lralile to arrest the y:old lint not so niiicli so as to perr
its Working; <lown ihi'oii;.'h it any ureal distance.
Ilavinjr i'stalili.shfd the fact that irold is derivecl from uraM-
n-niains to Im- shou i that it comes from the I'ocks which make up tiie
liiilkof the irravels — that is, schist and i|uarlz--and that it is not from
material intr<Hlnced into iht' ;,'ravels at the same time with these rocks.
In many of the •rulches (piartz veins which carry free trold have heen
found in place on the hillsides, ami in nearly all the <ridches hloeks
of \ein ipiai't/. an- found in tlu' irravels, which, from their a|ipearance.
ci.n lianlly have liecn traiisjiorti'd far. and which are also found to
lie froUI-l»earinv'. In the jiay irravels, moi'eo\er, amon-r the smaller
frav'nients and nuL';reis, ai'c found ;rold and i|u;irt/. in the same frair-
nient- ami in all relative |ir(ipoi'licuis; so that a series iui;rht he
hnui^hi to;reiher lH-;:inuin.ir with frajrmeiits of i|uarl/ eontiiinin^
M-anis and flakes of jrolil and cndiiiLT with nuirirets carryini: irrains or
x-anis of ijuartz. Nearly all the lai'ire lumps of irold contain eon-
si<leratile <|n;iitz. and even the vei'v small pieces often show under
the nilcro>4-ope fi-airmeiits of <|uart/. clinirinir to them.
When the pay {travels are washed by water in tin- sluice l»o.\es or
other <-ontrivanees the liea\iesl minerals are se])arated from the liirht-
est, which are cari-ied away liy the water. In the concentraie left
Ixdiind there is a variety of minerals besides jjold. ami these mitiei-als
.•.how e^ ifleiit derivation from and dependeiu'e upon the roeks whi<-li
eonstitute the larjre fratrments in the firavel. Thus, in the gulches
under considenition, the heavier miiu'i-als are almost entirely those
found aliundantiy in the liirch Creek schist — ehielly hornlilende.
niajrnetiie, and linmnite. When jraiin-tsare found in the schist these
are al.so present in the concentrates, ami in about the same relative
abundance. Fn ijueiitly <:alena is found, and in m-arly every irnh-h
where this is the ease, as, for e.xamiile, on .Miller, (ilaeier, and llog"em
t-rei'k.s, veins of iraleiia have been found in the bed-rock.
eri'iiii]
OKIGIN or TlIK I'l.ACKli (iu|.|)
371
lill.c 1IK> IN hiiUTVMll.K IMi K*.
A iilliiilM'r of ;.Mlli'licM wliicli liiivr yiddnl ir..l<| In p.-iyiii;; iniaiilitii's
flow entirely tliroii;,'!! Ilie rueks >.f Ihc Fcilymile series. Aiiicm;:
these Franklin (inlcli in the Fortyiiiiie (lifiiiei ha> pn.haldy I n
the richest, anil may serve as an example I'nr all. 'I'liis is ni-arly a
strike fiiileh. llnwinjr alc.iiy:lhe nptnriieil ed^fesof niica-ainl liiirnldeiiile-
sehifsts interbedded with niarhie. 'I'hese schists are iiil by l'rei|uenl,
dikes. At the extreme head ot' the i;nlcli, I'Inse to liie divide, is a
jrreat dike or intrusive mass of j;raiiile or iria liorite. 'I'h,. u'ravids
in the creek bottom are composed of tin- same iii/ttcri.ils as the walls
of the valley, and contain besides these materials freipuMit tniLrmciiis,
often rouniled and of lar;:e size, of oli vine-basalt, a i k which ll,•l^^
not been found in place here, allliouch it occurs abundantly Just to
the south, in the country drained by Chicken (reek, (iold has be(>ii
found the whole lenirlh of the ci. „ ,is far as prospected, and occurs
in the very bottom of the u'favels oi' In the irrcy:ularit ies of I he under-
lyinjr )>ed-roek. The thickness of pay ,i;ravels varies up to aboiii i'
I'eet, and above this, as in other jiuh-hes described, lie barren ^i avcls.
which, liowever, do not dilTcr in f,'eneral ai)pear,iiice from those which
contain ;rol<l. Kvery indication shows that here, as elsewhere, ^old Is
derived from the j;ravels which now lie In Ilic bottom of the uulch.
(illAHKS IN ItAMl'Alll Hoi KS.
On Little Alyiiook and Hunter creeks the l>ed-rocks are of diabase,
til lis. imi>u re shales, and (piart/.itcs, and in the bottom of the .'{ulclies
tliesc ro(d<s aro overlain by from io id jo feet of i:ravcl. In part the
gravels are large, angular fragments of rock like that forming the
■walls of the gulches. Thi.s material shows little wearing by wati'r
action antl little assortment, being essentially a slightly arranged
talus. Jicsides this, however, there is a great deal of waterworn
mati'iial, consisting of well-roundeil jjebbles of rocks which <lo not
occur, so far as kno«n. in the drainage basin of the gulches, .\moiig
tlie.se fragments arc conspicuous the roundcil pelibles of liirch Creek
schist, of schistose granite, and other rocks. The roundeil fragments
are mingled with the angular material of local origin throughout the
whole tliicdiuess of the gravels, liciieath thedetrital accumuljition
the bed rock is softened and decomposed for about a foot below the
surface, and in this altered rock nearly ail the gold is found. Ilelow
this the fresh rock is barren, while above it tlie lower part of the
gravels sometimes contains sutlieient gold to rei)ay working. It is
evident in this ease, as befoi'e, that the gold has been deiiveil from
tho material wliieh now constitutes the gravels, but here the material
has a twofold origin. Tlic rocks through which tin" valley cuts :\vr
traversed by numerous shear zones, along which sulphides containing
at least traces of gold ami silver have been deposited; and there are
also frequent quartz veins, sonic of tliem of large size, which are
87:
(iKol.OGY OK TIIK Yl'KON GOLD DISTRICT, .ALASKA.
■jl:
V. i I icp cMiTv ii'ilil. Sinc-c llii'si' ripcl.N iiijikc u)i ilic most <tf ;;ravel,
it is proljiildc tliiit tlii'^'iiM I'limul coiicfMlrali'il in tlic lifd-rnck Ih-Iuw
is jiarlly, a I least, ilcrixcd fimii I lie in. On I lie ullicr liami. tin' nniiKlcil
gravels (if more rermite (ni^rii ar'e ot' liiri'ii C'rcelc rocks and oilier
schists wliicli arc known to he iiold-liearirivr: it is tlierefon- |(rol)al>le
tliat these also liave cont rilnitecl soniewlial.
On tile upper pari of American (I'ci'k wliere jrold occurs the rocks
wore, so far as examined, massive serpentine- and cidorito-t nil's,
impure lirie-irrai.'ied (piartzil.-. and sandy limi-sloncs. At the only
claim .vl'icli was Ipein;,^ uni'l^ed t lie ;;ra\t'ls in the Itottoni of the ,i,'idcli
wore exceedinj^iy liariiiw, often not more than liiorl"i fed wide. 'I'he
delrilal aceimuilalion at Ihisiilacc is only about :} or \ feel thick, and
is entirely made up of anj^ular fraLcments of the rocks which overhang
the St ream jirecipilously, ami of the <|uartz veins which these rocks
often contain. This fiati'iiieiital deposit is nearly liarrcn. all the ;,'o;d
bein^' found on tup (jf the lpe(l-r<ick beneath. Here iIm' f,'r;!vels havt>
ftppaieiilly yielded the jrold, wliicli has been collcctctl alonj; schis-
tose /oi:e- (if ilie umicrlv inj,' r.iek, aiicl these i,'ra\cls seem to have a
inirely loi'al source. Associated with the ;rold, in the \cry bottom of
the {Travels, are freiiueiit rounded or .suiiaiiirular pebbles of ina;r-
netite and oarile, wliicli scom to be derive(l from the veins which fol-
low the shear voiics in the neiiihboriiiir rocks.
I
m
S(MH( K dl' rill-. IiKTIMTAI. At ( f M 1 I.A 1 li >NS IN <.l|.( IIKS.
It has be<Mi shown thai the jroM found in iheirulches is (jerived by
concent rat ion from the e;i'j(vels, which are iiia<le iqi -^f rocks in \."hicli
pilcl occurs disseminated; and that these j;ol<l-beariii;j; rocks are
cliiedy those of the Birch (reek and Fortymilo series, and to a less
extent those of the Uampart series. It maybe ailvantaj,'eous, how-
ever, to coiis'der lirielly the mei'.ods by which tlu' fra;rmeiits have
been broi!;rhL to their iiresent position, since a kn(iwled<,'e of this i«
essential for liiiding those parts (jf the solid rock that are richest
in pild.
Till- oriirin of the most of the detritus in the ;,'ulclies isclearly shown
by its nature. The aceuniulalions in the richest- disi 'iels consist
almost entirely of ilat and often ra;r;red frajfineiils of schist, witii
larije, irrey;iilar bowMers of (piariz and eonsiderable line soil, all i>iled
tutrelher with little assert meiit. The male/ials are ;:eneral!ythe same
from top to bottom. As a rule, the frai;meiits eoiisist almost entirely
of rocks identical with those ii; the walls of the ;:ulch. and often slic^v
chaii}re.s in dilTerent parts of the {^ravels eorrespondin^ to chaiure:, in
the wjill rocks. Apart from this evident relation, it is clear that those
larf,' ', Ilat fraj,nneiils of frajrili- schist can not li,i\e been carried far
froi their original source; and (he same is true of the large bowlders
of (|uart7. and associated rocks. Any great amount of water ai-tion,
moreover, such as would be necessary for liaiisjiuitatioii, would Luvu
w
•^
8Pt Rli
ORIGIN OF TIIK I'l.ACr.l! liOI.U.
roimdod and assort o< I ili,- t'latiiiu'iils. 'I'li.Ti'lur.- tli.> man-rial is.'ss.Mi-
tiallya talus \vliic]i li,,s Ih-cu sliuditly arraii^'i-d ;lii.u-Ii iidt ;.'rt'atlv
niiMlificd.
.Morcovor, those iiortioiis of the jrravcls wltiili ar.- most liitrhlv
auriferous sometimes hear a relation tocertain parts. if th.- asMH-iateil
bed rock. For example, on Fraiikliu (Juli-Ii ,->oarse ;:ol.l is found
.nhundantly just helow a w iile (piaii/. vein in tin- tied of the «uleli,
while ahove the vein the irold isliuerand scarcer un n,i;.'"eiii Creek,
in the gravels which overlie tin- broad jrranite dike, the ;:..ld i-. tine
and comparatively scarce, hut coarse ^rold is found intlieschi>i imme-
diately above the f,'ranito contact and from there enuiiuM.iuslv
upstream. It is possible, however, that in this cjim- the ^'leater
conc'i iitration of the j;old on top of "the schist as <ompared with that
on thc.srranile may bo duo i)artly to meclianical aeiiun, tlie rid^"-s of
scldst operatin^f as natural rillles. On Napoleon (reek l'oM occui-s in
notable junouut <udy wiiere the licfl-i-ock js a ceTtain ciiai>e cumrlom-
erate, derived chietly from the old .^'old-bearin,' ro.-ks, while the
frravels which lio in the rest of the creek are ])raeti<-ally barren.
Cross sections of the jrulclies have nearly ;d ways a ^.'eni-ral V-shajie.
The smallest streams run in veritable iiolches, while the laru'er ones
widen their liood-plain s(( that Hie bottom of the V Iwi-onies broadened
.indllattene<1. From the sleep walls of tlie^ridches fra;:mentslo<.-iened
h\ frost are continually slidiiiir down by foi-ce of ;rra\ it v or are uru'ed
down by freshets or heavy >nows. ^■( i-y fre((iiently a c-i,n-iderable
accumulatiou of these fi'ajrnienis comi's clonii sucldenly in the form of
landslides. At the bottom of liie u'uicl, tin- ileirini- i-- >mootliei| and
sliirhtly arranged by the waters.
It is sometimessupixised by minersthat the L,'i-avels may Ite due to a
jrencral j:lai'ial action, which has bi-ou;,'hl i he auriferous material fiom
some unknown distant souri'c. It i-. ho\\r\i-r. (piiie elear that y:laeial
action has been [(rail ically absent in the lii>iiir\ of the eonniry. Not
only was there no general ice .sheet <'o\i'i-im: hill and \ alley, but e\en
local glaciers, lillinii; t!ie \alleys while lea\inLr ihe ridue-. free, were
absent That this is triie is shown by the total laekof all iilacial phe-
nomena and by the ])reseni f pinnacles of roek whieh have bii'U
left by dilVerentiai erosion ami which nould invariably ha\e l)een
broken diwn by a glacier. Kxam|)les of ids are the l>ea<lwoiMl I'.uties
on l)e,'ii|\v I or It.ig'em (Julch. \vh 'ii are tall pinnacles of granite
siandingon ihesiileof the \ alley i-.t far from the bottom. In the
formation of t he ])r( sent \ alleys, however, the action of ice and sno,\-
has hail <'onsiderable elTeel. In iln' ni'ire ele\ ated gulches coiisider-
abk; snow accumu'ates in the winter', and in spring soon beeomes
ice, wldch moses slowly <li)wn o\ei' the steep ..icles ami head of ihe
valley. This action is especially marked in \allevs wldch hea<l in
high hills, and in these valleys the aceumidations of iee and snow
persist at the head of the gulches after they have disap|M'ared from
p^
R;.'
374 GHOI.OUV OF TIIK VUhOX GOLD DISTRICT, ALASK \.
tlic main part. IxMiiy- \f<\ from Ili<^ liills. 'riie (•..iisolidalion of tlioso
.snows by allcniatf Irccziiif; and tliawinj,' iirodiiccs a iiia.ss of Ico
wliicli. Iliniii;!) tcmiMirary. has all llic cliaractci-islics of ii true glacier;
and by 111.- .lisniptivc action of lliis ice and tlio olTccts of the water.s
derived from its iiieltin;r. Hie head of the valley is l.roa<lly and vif,'-
on.usly eroded, so that, it heconies wider and Halter than the rest.
In tills way. in >rnlelies which have an almndaid supply of snow, the
hea<l is converted into a typical cir(iue or ami)iiithealer, such us '.hose
in whic-h ;rlacial material usually acciimulat<'s. The porfection of
this foi-ni is seen cv .'rywln'rc to he in direct de|)endence u|)on the
amount of snow; ;in<l \vhere it is most perfect, eousiderahle patches
of ice often last throu,i:hont the sum r, while in other cases tli(> ice-
is eiitirelv melted. The saiiiecrosivi' action sometimes tends to widen
the valley by more rai)id wearinj: away of the side slopes. Where
this viiroroiis erosion tal<es place the heads of the valleys are free
from iletrital a<'cnmulations. while farther down the .yravels are con-
tinually snpplied with new material; and this material, miniilin.',
with the tains derived directly from the sid(-s. is can'ieil downward,
esjiecially during spring freshets, so that the accumulations are tliiii-
uesl at the head and thickest at the month of the valley.
In many cases, liowcver. tlu're are found, nu\ed with the largo
aiiirular or siibangnlar fragmi'Tits which are so <'vidently derived
from the rocks of the vicinity, small ■well-rounded |)ebbles, wliose
form indicates considerable transportation; and on some creeks, as,
for cNamiile, on Hunter ami l-ittle Mynook, the ])ebbles are of ro.d^s
which are not found, so far as known, in the drainage area. These
well-worn gravels oecnr not only in the g'llches but also in the
uplands; thus Ih-'y cover the whole of the plateau through which
llnnteraml I.ittle Mynook creeks cut. The .source of these gravels
has alreatly been discussed, and it hns been suggested that ])art, at
least, have a mariiM' origin, or have been arranged in their present
fashion by marine action. Since they are couipo.sed in large part of
materials from the gold-bearing IJirch Creek and Fortymile rock.s,
and sini'c on high terraces above the present rivers and on uidand
benches they have been fomnl lobe auriferous, it is probable that
from them some of tliegohl in the gidches where they ur is derived.
(•v.ing to supi)ly of this nuiterial from .sources outside lhedraii\age
l)asiii, the gravels on some of the gulches, such as I.ittle Alynook,
Hunter, and Franklin, are as deep at the head as at the nu)u1h, or may
hi' even ileepiM-, since the gulch gravels with increasing elevation may
reach nit and blend with the thicker accumulations of the uitlantl.
OKU. IN OK THE \'\..\<y.li ..oi.I).
■M')
IIA-VNKK I IF ckNI KNTKATIo.V <tF (,<il,I».
>K MKt llAM. Al.
•N' FNTI!AT1"N.
My previous <lfrs<'iipiiiiiis it i> .^.-i-ri iliiit iln- \sii\i\ <iiiL'iiiall.v disst'iiii-
iialcd ill tlu' j;rav('ls wnrks ilownuani in oIhmIjimu'i- to 1)1, • I'oi-cc n(
jrravily, tlins clVi'diiii: a cuiH-i-iitraiiMii variiiii-l\ pi-il'iMi in <iiiViTciit
pluft's, anil that in liiis jirocos tin- |»a!»iti.'i- oi' the ;;iili| particles is
moehanieal. 'I'liis ernH'einratiim would liar<ll;- 'm- pi.>-ilil.. iiiili'^s the
iTl'avels \vefi> t'fe(|iientl\ s!i'_'iit!y iimveil or iJiM iirlwil, m> a> tci permit
iniiveilielll ailliillU' 'lie [lai't iele-.. It i> iliiiliiiiliteilly true that a la lire
l)ai'1. (if »lie lii-aina^'e water |H-ri-i>late> tlir<Mit:li ilie iriaveN. uiii<h
are eoaise and puioiis. ami the pa»;i::e of this water iiiav In iiiir almiii
enon^jh tiinvemeut to permit a eoiiiiniial H'paiatioii iieenrdln;: to
speeil'c u'l'avity. The alti-rtiate fri-eziii;: and '.iiawiii;r <>( the ;,'ra\el>
wliicl. lakes plaee in this letrion in the warmer pail of thi' year. \\ hen
the ;, ravels are tiiawed l>y day and frozen liyniiiht. must al-u prinluee,
hy all e mate expansicui ami eontrai-lion. mn<-li iiio\iMiii-nt which would
I'aeililate the downward pas^ai:"- of the u"'ld |iariieles. Wlieii condi-
lions are so favoraltle that nior>t of ilie jiold thus works Ik was to
the bottom ot the irravels. its retention :in<] <-oneeiiiration dc|ieiids con-
sidcrahly upon the ehai'aeter of the ln-<l-n"-k. If this is a schist, and
especially if it is disinteirfated. the ;:old '-comes lo<ly:ed and can not
he earried farther. Also, if the lM-«l-nN-k :^ lull of eraek~ and irrey^u-
larities. smdi as a iiineh-.joiiit*-*! — L ■■• a eoaR^e eoiiL'lomerate like
that of N'ai)oleon Creek, tin- irol. .■••1 in tlie s.ime manner as in
the seiiist. If. on the other liai, '--d r<"-V ■- comparatively
smooth and hard, the trold may ]»»• cjirin- 1 nioic favor-
alile plaee for retention. Thus, at he I j., ,,.,.,1, on Anierjeaii
Creek, the fiold is praetieall.v all foiin<l in tie- iipiiermosi pari of a
narrow zone of schistose, iniimre i|iiartzite. vhile .ilpn\. .md Kcow
this zone are massise seriM-ntine r«H-ks. ]iiesentiiiir a ^iiiooili. h.iid
sit^'face. and these portioii> of the creek lioiiom were almost entirely
barren, since the rock otTered no irreirulariiieN to arrest tie _'ild par-
ticles.
The ed'eet of schists and other nx-ks of nneipial hardness in the
eoiieenlration of <;o!d ma.v Im- eom|iare<l to th; 1 of the arlilieial ritlles
in (he sluice box ami other contrivances iis4-<l liy miners. These rifles
are slats introduced in the l»o\ ortroimh. and ari- ^'etierally |i' n-etl
pari>i!i 1 with the current, althiiii;;h often at <litTerent anirles wi the
water plnniifin}^ over the»«' slats vortoxcs are pr<Mlticed. by which the
gold pai't i(des are carried info still wat«-r in the shelter of t he slats and
Ihero lodj:e(l until the- i-iirrent is turned oiT. In a sticaiii the same cur-
rents and vortexes are pnMlin-e*! by projei-tiii;; ledjres of rock, and
roit};h waters or lapids result, which are by the niiners also called
rillles. These iirojeetinj; led;ies do not e.visi in homo^'eiieous, tnassivo
1^
37G
(;k<)I.o(jv oi' the ylkox cold KI.-TRICT, ALASKA.
m
rucks, wliilc in sdiistdsi' rm-ks ilicy arf ••vi-rvwlicrc well iiiiirkcd.
llciico in till' Fmlyinilf aticl liin-li ('r»—k <li>lri<'t> ••vcii tin- iii|;;cs
diviclin;,' tlio jj;iilclics Iiavi- I n ^"^ iTiHlf<l ihat tln-ir suiiiiiiils iiicscnt
a sciics of stops, j^iviii;,' a sa\v-liMiili<'il apiM-aniiicp. (Sec fij;. :.'."i.) In
tliis case the sf('])s or li'clli an larirt'. ill'" <listain-<- vertically from the
crest to the ti'oii;,'li of the steps heiiiu' ■'>'< feel or iiion^. In tlie sti'cani
\alleys there is lh(> same strin'tiire, only the t<-<'th are smaller and
more iiumei'oiis; thus nil l'"<irtymile (reek at low wafer there is ji
roiitiniial succession of rillli's or rapids. In the smaller streams };old
\vlii<'li is carried by the current may 1m ilrojipo*! on eneountei-inu; these
\ orle.xes, and may lind its way into >lieltere<l places or cracks of the
Bcliist, from which it. can not he dishnlitetl. This concentration lias
actually been observecl in the |)resent streams, and considerable gold
is sometimes taken from such natural rittles.
In the case of art ilicial litlles in sluice Imixcs the slats may o]»erate
to catch the j,'okl otiually well when lyin;: at ililTerent an^'les to the
direction of the current. In the same way the .strike of the scliistosity
of the bed-rock with reference to direction of the overlying: stream
seems not to be of y real importance iii deterniiniiiir the concent lal ion
'i*-
Flu. Uo— Uiai;raui ahuwiih' siiw-likc form iirn.ln'^ bjr erosion in onj^iualiyKrc-MoiiiHMl sihist
rlilgra.
of IT" lid. 'I'lllls. when We eoli-i(le|- the rich gulches which ha\e been
examined, wc lind that (Jlacier and .Miller, in the Koriymiie disi lict,
tlowwiih the dip at riirlil an;,des to the s<-liisi<isity : iliat .Mastoijon,
Jliller. and Uoiiaii/a. in I he ISiicli (reek district, run across the ijip
at rii;hl angles lo the scliistosii\. whili- I'oker. Franklin, and the
hliiliesl part of Harrison .ire para 1 I, and llou'eni Crei-k obli<|Ue |o it.
(lold which is now beiii;; accumulated in the Iwd of the present
stream may be co\ ered by -gravels by a sli;:lit swin;: in the current.
In this case I iiis pori ion nl' the valley will 1m- richer than neiirhborint;
imilions. Ill otiier parts of the i,'ravids ii which the "old was oi'iu'i-
naliv iinifiu'iiily disseminaleil, the metal vill Im- Im-sI concentrated
where the water has iiercolaled most, for this iinderjirround watei-
must lia\e deliniie channels, althouirh not so i<arr<iwancl well defined
as those of surface waters. It thus happens that <-ert,un p.irts of the
jrra\els and of the underlyin^r bed-rcH-k are mon- jirolitable than others,
and these are often called " pay streaks." <»ii ^liller Creek, in the
Kortymile. a pay streak is reported which was ;! ^-et wide and i'> feel
deep, I'siialiy. Iiowexcr. it is much wider th.i'- det-p, and oftiMi the
gravels in the whole bottom of the yiildi pay f<'i wi.irkin|j:. Since the
OKinix OF THE ri.ACKK r.or.D.
,'577
und«'r,rr«juncl water, wliich soems to In- larizdy iiisi num-iital in liiiiii:-
ing alKiut tlie (•<inceiitrati(ni of }j;o)il. must Ik- most al>uiulaiil in tin'
Ijoltoni of th<' Iwil-rook valley beneath llie irravels, it is liei'e that the
rich«.-st i»ay streak slioulil be expeeled. 'riiereldic, when the stream
is fviil«-ntly uii^rratiiij: lalei-ally and is eoutinnaily eiittiuLr into the
limits of its old valley on one side and leavinir behind it an old
floo<J-i»!aiii <in the other, the pay ^'ravels will be mostly founil in
tlio fl<i<jtl-i»laiii. In other eases, where the stream is more symmet-
rical in r<-frard to its valley, the jiay streak often wndiM-lies the jnes-
ent ohaiiiiel or is found on eitln-r side of it alternatelv.
I-<ISSII1I-K 1 HK.Mlc AI, INILIKNCK IN ( uNcr.NTUATH iN.
It is now known that gold, formerly eonsidered insoluble exee|)t in
tlie most i«»werfiil aeids, is in reality attaeked by nn'^iy eorfimon salts,
e>i»c<-Mally those of the alkalies.' Many of these salts are found
almost universally in snrfaci^ waters, having Imm-ii derived from the
8<iil with wiiieh these waters eome in eontael. SonsladI- has shown
that gold is present in sea water in a j)roi)oiiion of about 1 grain to i lie
ton. It has, moreover, been found by expeiimeni that y:old eonlained
in alkaline solutions may be i)reeii)itate(l by certain agents which are
everywhere abundant in nature. From such solutions of irold a pre-
cipitation may be ea used by the introduetion of a jiiece of tliesoijcl
nietal: an<l other metallic minerals, such as iron. c,i;... •, an<l arseii-
it-al pyrites, galena, blende, molybdenite, ami other minerals also form
fa' orjilile niielei.* 'i'his |)recii)ilation takes place especially wi-ll in
t?i<- jireseuce of organic matter, but also iti its absence;' and it lias
l>«-«-n shown that organi<' matter alone is sulliciirit.'
That these facts which have been obser\ed in the labor-atorv are
imiiorlant in eonsideiiny; the ordinary i)i'ocesses of nature is proved
liv many well-authenticated observations, in drifts through aurifer-
ous gravels jiyrite often forms, and this pyrile almost invariably con-
tains metallic ;:old.'' In p.ieces of wood found in thi' Australian
jfTiivels pyrite has been deposited, sometimes entiri'ly rcplaeing the
orgsinie s'rueture, an<l this pyrilecontainsgold ihroui;liout.' Accoiil-
ing to Mr. T. Kgleston." sonn- of the copper ores of Texas, which con-
tain Ixith g'lld and silver, oc<'ur in the form of trees. It has bei'u
Holed in the Transvaal'' and in .Australia'' that gold-bearing rocks
■ Fremy: En<y<lo|i.:-ilH' i'himii|uc. Tome III; lIK' ciiliiiT. p. *i.
>Am. ti^-iiii-t. V..1 HI. !■ -MS.
' H. A. Til iij]~.ii iJ.ilil Fi.hl'* aii'l Miin'i-iii Di^irl'i^ ■■f Vi.fi-iii. Mi>ll»mrnf, Isiiii, p. -.i;-.
• U«1UT Luul-. Milfnil. Matf-. Nmv , 1M':|. p, Jit. K v.m Knuil/: -Viii, iMnjluiti-t. Auk' . I"'."!.
p i-e
■•t-*! neM» »n'i Minvnil I'l-tri.-t-, ..f Vic-i..i-«i. ]>.-K, T. Kgii-ntmi: Truiis. Aui. hi»l .Mm.
Eivf - V.i IX. Ji, tlfi
•G-W Firkl.amlMluiTal Uistri'-I« .if Vi.t..iiii. p :.'lii.
'<'»}». ot . pj. 'S**.y>\.
•Tran» Am. liiKt Mm F.iii.'-^ . Vol IX, ji il4.V
• Ant <i«4.jBiM. Au(t . !■<!•>. p. lit-
:' T. A Ri'-kani. (.Vrtain lUmiimilur i)i'imiiti.'1i<-v3 uf i.'.ilil-lH':iriiiK 'l"i"''2- Pri«-. ('ulnnulo Sci.
.'578 CiEOLOfiV OF THE YfKON GOLD DISTRICT, ALASKA.
m
Ml
i;
hov.omo eHpocially ricli in tlioso layers m- beds wliicli oontiiiii iiuich
orpiiiic iiiatlcr. In placer (•(iiiiitries jtlates of irold are sometimes
foiiiid ill the trrass roots, heintj probalily prveipiialed tlieic by tiic
or;;anic iiiateriai.'
It is iiiipossii)le todoiiht. therefore, that solution anil redeposition
of .u'oid take place eontinnally In nalure under the inlluenee of onli-
nary draina;rc' waters; and in auriferous {.'I'avels. wliieh are porous
and thus opon t<( the circulation of watiM', jiroeesses of this nature
must ii<) on continually. Indeed, proofs of this are not wantintr.
Aniouir the most con\ incinjr of these is a si)ecimen shown the writer
by Mr. II. W. Tui-ner. of the (;eolo;,'ical Sui'vey. This s|)eeMiien ci'U-
sisted of placer }rold and black sand from the auriferous ffravels of
Providence IIIIl, I'luiiias t'ouiity. California, the black sand consist-
ing; mainly of ma^rneiite. with some hematite an<l possibly somo
ilmenite. .Most of these miiier'als liave a nearly perfect cr'ystallino
form, althoui;!) the edp's are sll.L'htly worn. Tnder the niici-oscope
several .small octahedra of maunetite are seen to be paitially coated
with a thin crust of irold, which was e\ldenlly deposit eil \-erv recently,
since It has been laid down upon the broken edires of the crystals.
This case is evitlently analopms to the laboratory expei'lmeiits which
have been mentioned whero {.'old has been precipltateii fi'om solution
by metallic minerals.
liul althou;rli this solution and deposition of jrold by sui'face \ialers
undoubtedly takes place in auriferous {travels, yet it must be reniei;i-
bored that the solvents act with jircat slowne.ss, and would reiiuirean
immense ])eriod of tiin«> to accomplish tlie transference of any jrieat
amount of iridd as com])ared with the time re(piired for such ti'ansfer-
eiiee by the active processes of nieclianical abrasion and concentra-
tion. The actual value of chemical inlluenee, of cour.se, will vary In
difTi'fenl count r'ies, belnv' doi)endent upon the nature of the percolat-
injt waters, the iiresence of materials capable of brln^inj; about a jire-
clpitatlon of irold hehl in solution by such waters, and the lenjrth of
time durinj^ which those proces-ses havi' had o[)portunity to ,i;o on. It
is, however, probable that, as a rule, mechanical ellocts have been
vastly more important.''
It has been asserted by some writei's that the larj^e nujjuets some-
times found in jrra\<'ls can not be derived from veins. In Califor-
nia, iiccord I njr to J. I). \Vhitney,' the larfrest nuj^iret found weijrhcd
about -•") pounds, but I'l-ofessor Wliitin-y points out that hirfje uua-
ttets were rare in thes*- ^'rjivels, and that larire masses of j;old were
found in some of the i|uarl/ veins. In Australia the lai'jiest nuf;y:et
found (the "Welcome" nuj,';ret) weijxlied over 1^4 pounds. From a
([uai't/, vi'in in New South Wales a block of ;,'old encased in <|uartz
' Trans. Am. Inst. Min. Eng., Vol. IX, p. Ui.
• F. l'iA..i)n\', Oi^nesix i>f on- ili'|K«it«: Trans. Am. lu.ft. Mln. Ens . IWfl. \>. Vil
• AurifLTous Wmvi'Ls ot tlii' Sierra Xovudu. \i. .W.
I
fi'tnii.]
ORIiilX OK THK ri.ACKI! Gdl.D.
»i "* t\
was takon from tlic sml'acc fiunipin;! ni' a vein whicli \v.'i^l,f.l 7.".
pounds, (Hit of wliicli iin pounds Well- iiuic Lfuld; t'mni aiinlliiT i|uai't/,
vein a mass of ;;old \vci!.'liin,i; ovor 4o puuiids was taken, and with it,
other smaller jiieces, weiifliinjr in tlie aLri:i'»"-iile ovi'r :!:! i>ounds more.
Ill till' I'ral .Mountains a famous nuir^'el was found at Miask. wliieli
was free from quart/, and weiirlied over S7 jioinpls.' It will thus tie
seen tlial masses of u'ol'l in quartz veins have approached \eiy nearlv
tlie si/e of llie hiriresl nuir^'els. .md tli. in .\uslra!ia sueli masses
have heeii found weiirliin;,' several time is much as the l,ii;:es.| nug-
gets in tlie (alifornian j;iavels. It is evident, thefefiiii'. thai it is nut
necessary to appeal to chemieal ael ion in the gravels tciaiiuiini I'm-
the forimition of nu^TLrets. In the Alaskan irravels a stud\ of the
nature of the ^fold shows that ehemieal processes have had very little
to do willi its eoneent ratio:'. 'l"he metal oceuis in irreLTulai'. Hal
scales, like those which are founil tillinir the erai'ks in thi' quart/,
veins, and a tuammillary form, su^'^cstinu' deposiiidu from sdliilion,
has not been notetl. 'I'he Hat forms are best seen in ihi' smalli'st.
grains, the larger nuisses having been generally snincwh.ii loundi'd by
eontael with liarder bodies. .Moreover, the gohl. fnim the smallest to
the largest fragments, is often mixed with vein quart/, in all ]iiiipiii-
tions, in such a maniu'r as to leave no doubt as to the det lital origin
of both. \o large nuirgels have 1 ii found in the .Maskaii gravels.
the largest being the (Uie found on I'lauklin (Julch, which vveighe<l :;i)
ounces. These nuggets have usually a higher percentage of quart/,
intorinixetl than does the finer gold.
* Uuld Ficlil.s auii MiULTttl Distnct-s ui" Victoria. i>. Xto.
I
r
i) \
CirAPTK R VTT.
COAIj IX TIIK XKIOIIIJOIMIOOW W TIIK GOT.T) HF,Tyr.
OCCURRENCES.
Tlio thick bods of tho Konai sorios are characforizod pvorywhcn:' by
nbuiidant plant ii'inains and by more or less eoaly layers, ami lliere
frcqueiitly ocieiir seams .)f pure eoal. Tho underlying :>[ission Creek
series is also highly earbonaeeoiis in some parts, and also inelndes
beds of coal, but, so far as ol)served, these beds were impure and
slaty.
On Lowoa River, a few miles above Rink Rapids, thcrv^ is on the
right-hand side a blulf where several .seams of eoal are expose(i. The
htwest is about :i feel tliiek, of wliieh probably about IS or I'l) Inches is
elear coal. Thi.s eoal is rather slaty and lignltie, and probably eon-
tains much ash." The seam is underhiin l)yu gritor feldspathie sand-
stone carrying plant remains. I'nder the niicrosco[)e the fragments
of this rock are seen to eou-sist ])artly of (piartz and jdagioclase, but
ehielly of a mierofelsitic material which carries many small needles
of plagioela.se, and is evidently, the groundmass of some andcsitie
lava. 'rh(> cement is generally a cryptocrystalline paste, although in
parts it ccmsisis largely of calcile. Above the coal seam come (; feet
of clay, with sandstone and grit layers, and over this lie about 10
inches of coal like that mentioned above, but probably more argilla-
ceous. Xe.xtcomc t feet of lava, having line amygdules at the bottom
which grow ])rogressively coarser toward the top; it is thei'eforo
a surface flow. Tho rock is light-brown, with light feldsjiar plieiio-
crysts, aiui under tho jnicroscope soonis to bo probably an andesite.
'J"he phenocrysts are a clear and glassy phigioclase, altering along
cracks to calcito. The gnuindnmss is holocrystalline, with a llow-
structuro, and consists abnost wholly of small, hith-shaped plagioclaso
crystals. Over this lava como about 18 inches of coal as before, and
then clay, sandstone, grit, .shale, etc. A tunnel has been run on the
principal coal .seam for a short distance."
Coal Creek runs into the Yukon from the east side about 8 or 10
miles north of Fortymile Crook. The writer has boon informed by
J[r. W. Ogilvio, of the Canadian Survey, that about 12 miles or more
up this crook there aro two 4-foot .seams of coal, separated by a bod
of clay containing leaf impressions; the country rock is sandstone.
' O. M. Dawson : Ann. Kept. Ouol. Nat Hiat. Survey Canada, Vol. Ill, pt. 1, p. HHB.
3S0
w
PlTKIt.]
f.'OAI, IN Till" NKIi;ill!i)HIH)OI).
;5si
SiK'cinuMis of tills ciial wiiicli witc .sccii liail a ln'iillaiil lii^liT. m ili
(■onclioidal rractiiri', ami wcrcDl' not iccalil.N liu'li' wcii;lil, 'I'lu-y I'cm-
taiiifil tiny specks of jiyrili' and grains ul' aniliiT nr aiiilH'i--lik<' ri'sin.
Tliis coal is said to Inirri w illi at)oul '< per ccnl of asli.
t »n llic small creek a lew miles hduw Coal Creek, on Ilie same side
of the Yukon, coal of llie same iinalilx oi'cnrs.
( >n American Ci-cek, and on Napoleon ( reek near llie head of T'orty-
inilc Creek, iniinin al seams were fo\ind in I lie Mission Creek seiics,
bnt no \i(»»\ coal.
All tin- localities w liicli lia\ e been mentioned aliove aie In ( anailian
territory, yet are in a rej;ion so situated jreoijrapliically llial il-de\el-
o])nient anil tlial <if the retrion on the American side of llie inierna-
tional boundary must idways ^:o hand in hand.
^\nicrican Creek, as the name indicates, is in .Vl.iskan leriilory.
Here the .Mission Creek .series contains nnmy seams of impur al,
and lai'fie fratinients of pure, iilossy coal with conchoidal frai'ture
were ])ieked uj) in the stream bed. This coal burns quite readily.
As a rule, however, the coal found in the seams of the bed-rock con-
tains pyrito and much suljiliur.
On the l.iij; lilack Hiver coal is relented by prospectors.
On the rii^ht-hand side of tln> Yukon, Just below the niouih of
\Vliyniper River — or Hess Creek — there are exjjosed fre<iueiit seams
of I'ather impure, lijrnitic coal which occurs in the shales of the Kenai
series. These shales alternate with confilomeralcs, firits, and imimie
linicstones. On thi.s blull' three distinct seams have been oiieneil by
Oliver sillier, a noted Alaskan prospector. One of these seams is ■_'
foet tliick, witli two or three clay jxirtinys; another, in which a tun-
nel m feet in lenjrth ims been driven, shows Ji or 4 feet of mixed
coal and coaly shale, and then a scam (»f clear coal b^ inches thick.
This coal is fjenorally brittle, and contains amber like that of Coal
Creek and vicinity. Next it is a l>e<l of yellow and red chiy, and
then comes airain carbonaceous shale, passinj; into jrreen sandstone
and con5;:lomcrates. All these beds are nearly vcrtli-al, and are even
slisihtly overturned, the folding beinj; well shown in the steep bluff.
Dr. Dall' mentions a small coal seiun belov Nulato, which, however,
had been squeezed out above and below by folding', so that (udy a
mere pocket remained. Ho also ment ions coal at various points alouj.'
tho coast, chiefly in the Kenai series.-
CH.XH.^CTEK OK C'O.VLS.
I'.elow are given two partial analyses of coals by Dr. H. X. Stokes.
The lirst is from the small creek which empties into tho Y'ukou below
Coal Creek, and the second from :\Iiller"s coal mine, nearly opposite
the mouth of Hess Creek. Tlio lirst is a picked specimen, and the last,
an average sample of a seam IS inches thii'k.
' Bull. V. S. Goot. Survey No. i<l. Correlation Papers, Xeweiie, ii. H'.
«Op. cit.,p. aff.
382
il
.(•i!
OEOl.OGV OF Tin; YUKON GOLD IiISTRICT, ALASKA.
Analyiux iif viiiitH fiiiiii Ihr Yiikoii irijian.
1.
Per cent,
Mnistnro 0.24
Volatile liydrocarbons.. 13.94
Fixeil fiirlxjii I 17. 7 1
Ash I a.0«
100
From Ihi'Sf analy.scs it will lii' .xocii lliat the per fciif of volatilo
liydrocai'lMin.s in l)otli casf.s i.s nearly (MHial to that of tin- (i.\i,'<l carlxni.
'J'he coal, moreover, eontain.s probably even more moi.sliire lliaii is
sliown in the analyses, for when taken from the seam if. is hard and
Instions, bill after exposure to the air its luster becomes dimmed and
it shows a tendency to crack and fall into small frafrments. These
samples, Iherefore, which are typical of all those examined and
described, may l)e called hard iiirnitic coals.
KCONO^lIC VAi,i'i:s.
Coal lias lieen found in many localities in the Kenai scries and also
to a less extent in the Mission Creek series. With fnrthcr explora-
tion of the country, it jiroliably will be found to be comparatively
abunilant. As shown by the analyses, however, those coals are of \-ci'y
low {jrade, niid <lo not jiossess hij,di heatinjr jiower. Dr. Dail' notes
that tlte coal of Kachcmak Hay. which is evidently of the .same
(piality as that from the localities described, lias been used for sleani-
inj; purposes and also for bui'ninjj; in an open j;rate, and has been pro-
nounced satisfactory. 'J'he coal from Coal Creek, near Fortymile
Creek, Wiis tried in a bljicksmitli's forj;e an<l was said to burn well.
Wherever these coal .seams were examined in the interior, however,
the rocks in which tliey occur are invai-iabiy stcei)ly incline<l, jiud are
often hijrhly foldeil and even contorted. This condition renders the
veins ditlicult and expensive to follow, and, taken in conjunction with
tlie low 1,'rade, nuikes it appear |)rob;ible that, althouj;h the coal may
in some eases be found convenient, for domestic u.se, it will not 2>!>.v
for exjwrtation.
It is |)(issilile, however, that in some of the older rocks coal of bet-
tor ipiality m:iy be found. Dr. Dall^ notes that at Cape Ueauforl
coal of a \ery ditVcreiil ipiality from the lignites of the southern part
of -\laska was found, in probably Carboniferous strata. Fossils col-
lected on the Yukon in the nei}rhl)orliood of the gohl belt show that
Carboniferous rocksare present in this rei;ion, but, so faras obser\ ed,
thev here contain no coal.
' Bull. IJ. S. Gfol. Survey Xo. 84, Correlation Papers, Xeoveue, p. 237.
»Oi). cit., p -'41t.
Wr
ClIAl'TKl! VIII.
ST'MMAItV AM> IMtACTK Al. A ri'MCAIH »NS.
siMMAKV III- i;i;i'iii;t.
'I'hf iidtcs wliicli liiivc l)ccii ina<l(' ii|)iiii llic iri'ulit^ry nt' iht- Yuk'>n
gold ))('lt iiKlicatc thai tlie i^colujiical ciilimiii in this if^'iini l>«-;:iii-
witli a fuiKlaiiKMital granite, wliicli is uvcriaiii by liiick i[iiart2itt->:
anil that tliis iniarl/ili' si'rics is nvci-iaiii liy inliTln'(|(lcil s..ilitiifiitar>-
rocks wliicli \vcr<; oiij;inally samlstoiu's, liiiifsloiics, ami >iiaU's. All
these rocks have Itcen siil).jccli'il to ri'j;ioiial prossurf, ami all \ut\v
b(!Oii rcinlcri'il schistose toiicthcr. Tlic ctTccts ot" the >!icaritiir. h'>w-
ovor, arc much more niai'kcil in the seilinientaiy locks than in tht-
inoi'(> massive ^'I'anilc. A\ aliotil the same time as the ilcvflopiiu-ni
of schistosity, probahly near the be^iiniiini; of this pinccss. .lik-"* u«?r»»
intruded into (ho sedimentary rocks ami iniail/ veins w.-rc t'>>riiii-<l.
'J"he series of igneous injeclions thus be;,'uii coniiniied for a hmg
jjeriod of ueolojiical time, and did not cease until after the end of tli«»
nioveinonts in the roeks wliicli fjave rise to the schistose striictiinf.
The first dikes, which were al'terwarils rendered sr-histos»' by >iil.— •-
(|Ueiit rejriiinal movements, were frraniticor dioritic, while later dik«->.
as a I'lile, were more basic and moi'e acid, and the linal in.jc-rions. *«•
far as observed, were of extremely acid dikes associated with •|iuir1z
veins. Previous to the intrusion of these xcry latest dike>. but at a
licriod when the development of schisli)sit> was nearly at an •-ml.
theio occnrred vast oiit[)oiirinj;s of basaltic and diaba>ic lava ovi-r
larj;e areas, and these if^neons rocks, with lull's and impure >;»nd>tr>ni^
hifijely derived fi i them, consliliite a vei'y thick scries. This •■••!-
canic activity seems lo have been very nearly the end of the i>«Ti«>"l
of disturbance which had been inaiiifesled by the shearinir. foldin^r.
and in.ieclioiis of i^nieoiis material. Sultseinicnl to the ontiH.iiriii-.: •>(
the lavas, however, dikes were still intruded, as is provtil by ilif
occurrence of these bodies ciiltinu the cIViisiNe rocks. l!ut tl»-s4>
dikes seem lo ^' loii;; chielly to the extreme types which chaiact.-ri/«-
the close of the .-eries of intrusions.
The i|uart/. veins which occur in the district seem to U- t-lux-ly
connected with the dikes, and were probably formed at siiot-sstie
periods. correspoiidinir with the repeated iii.jcclions of iiineoiis iiiat«-
rial. Therefore the oldest veins have been sheared toirdher with the
ohlest dikes and the inelosinjr rocks, and have been fault*-.! aud
3K4
r.Kol.MCV or TIIK VIKON OOI.U msTRICT, ALASKA.
»lr»-I<-h<-«l »> that llicyan- <liarm-t<'iisticfill\ narrow jiikI ii.iii|Mrsist-
eiil iiii<i difli'-iilt to follow. rill- lalf'st veins. Iiowivt'i', wliirli arconi-
|>aiii<-<l iIh- lal4->t granitic an-l aplilic intrusions, aii'. liki- tlii>f dikes,
iin«li«-ar«-<l an>l iiraeiicaliy nnliiiiileij. ami tlii-rcrorf may he in jiljices
«i<l<-aiii| jM-T>.i>ient. All tlie>e veins seem lo eai'i'y ;,'olil in v;tr>in;;
Mlliolints, Jlllil llieV proliallly are llie ellieC soliree of the JTolil now
Ih-Iiii.' taken from plainer ili;.'i:in^'s,
Followiii;; the ]M-rioil of ),rreat la\a ••niplions, litjiestones ami other
s«-<liiiifnl!» Were l.iid down, sueeeedeil liy more shaly'and eon^rlomer-
ali<- InhI:*. These .sedimi-nts are lar;;ely niariiH'. Iiiii have oeeasional
leaf bf«l.«i. iiidieatiii^ fresh-w.iier eonditions, and seattercd fos.sils
.••liow a ran;:-' iirol>al>ly from I >evoniali to Crela us. Altove tlieso
^«^•^liIllellts »a> laid down a very thiek serii's of fresh-water Ix-ds,
wLk-h an- largely confrlorucrates. coiitaininf: abundant plant remains
fciiid seams of li;:nitic eoal. This sei-ies, on the eviilenee of its flora,
ha> iMM-n referred to the Koeene. Siihsecpient to the formation of this
c<iii;.'loiii< . ,kti< >eries, violent movements took jilai-e in the earth's
«TUM. tir»-at folds were formed, amonu them thai wliieh has lieen
iiaiiieii tin- ••Yukon jjeaiitieline," which lias a northwest and south-
«-a."'l in-iid. The Ix-ds were upturned, I'.nd the developmi'iit of the
Alaska of tlie present day liej;an. I '.y erosion of the Yukon .ireanti-
clinf thi- difTerent formations were c.xposeil in northwest aiul soutli-
eaM trcMidinir zones. 'I'his is i-spi-eially llie ea.se in tin' lowor schistose
};oM-lM-arin:r formations. I'arallt.d with tho a.\is of the fjeantieline
the chief <lrainai;e was esialdished, and alonjj this line of draina;.'e,
whieli lias nii;:ratcd somewhat down the j^eiuM'al di|) to the north-
east, the Yukon Kiver now flows. I'.y the erosion of this and other
streams, tin- jiresent hills, mountains, and valle.vs l)e},'an to he e;irved
out. Since the pi^rioil of this revolution the interior of ,Maska has
Iindiiihly never Im-cu Ion;,' heneath the waters of the ocean, ami there-
f^n- the only suhse<nient deposits are scattered and are of fresh-water
<irij.rin: ahhou<;h nearer tlu' shore nuiriiie ileposits are found, sliowinir
that during >Ii<K-ene time the land areji was smaller than at present.
In later jre<>lojrieal times, however, the land has l)een suh.jeet<'d lo
repeate<l «»s4*ilIations, which luive involved {rreat chan-^cs of elevation
but havelK-t-n without aii.v^'i'cat amount of attendant foldinir. Thus.
after atmospheric a^'encies stihseciuent to the posI-Kenai revolution
had fa.shioned the topo;;raphy after tho same {jreneral pattern as that
at prt-sent existing, an elevation cau.se(l an acceleration of llie streams.
and deep can.von-Iike valleys were cut. The.se are still [ironiinent
features in the topo;rrapli.v. Durinj; this period also, which was proh-
ably mainly in the Pliocene, ei'uptions of olivinc-hasalt took place
from sepanite vents at various localities.
Suljs4'<juent to the erosion of tlie <'any()ii-liko valleys tho whole land
mass sunk iK-neath the sea, as shown by terraces which represent
proliable shore-Hues. The scattered gravels found ou mountains and
i
SUMMAKV AXD PHA( TICAL AI'IM.I< ATIONS.
88ft
ill Milli'vs all liver the c.iiih'ry sfciii to !>«• uik' «i|' llic cITi'cts of iiiiiriiic
Hclioii ill llils period; oilier llijiii llii>. lio\\e\er, no iiiarliie ile|)o>ils
lllive lieeli round, iilld 1 lie siibniefgence iiiilsl liii\elieeii briel. ills
prolialile that llie niaxiiiiuin Mitinier^rence may lia\e lieeii more or less
closely eonleniporaneous with the maximum evieiisioii ol' the irreat
cordllleraii ^'iK'h'r, and this may ex|)iaiii the alisence of ulaeiatioii
and also of ilo-ayed ;iek over so laru'e a portion of AhiNka. The eor-
(lilleraii ({lacier soon retreated, howexer. ami ihe laml al-o Ixiraii to
rise. On the retVeal of the sea. the eoiinlry lieiiiir si ill low , the valleys
of tilt," old si reams were ill part occupied hy numerous lakes, ihi' water
HC'i'limillatilif; ill coiiseiilleiice of the slii^'yisli draina;;e. or ha^in-. were
formed l»y local de[)rcssion or irre;;iilarit ies of tdevalioii. In ilioo
lakcH mud or silt rapidly acciimiilaled. Willi inere.isin;: elevation
some of the lakes became drained and others were rediieecl in e\ieiit.
The slreains became more rapid, and the \alleys bi'^riin to be exca-
vated a^'aiii. This is the condition of lliiii;;s at present, and it is
probable that the elevation is still jroiiii: on in a general way.
Auriferous (|iiartz veins were formed in the ojijcr rocks at dill'ercnl
intervals, and tlieir formation was accomitanicd. in a j;ciieral wa.\, by
tlic devclo[)inent of schislosity, so lliat the veins may bedivideil into
an older sheared and ayoiinjjcr iinsheared .set. These \cinsarc found
chiefly ill the lii},dily schisto.sc sedimentaries whii^li have been called
the iiircli Creek and the Kortyinile series. They are occasionally
found in tlie fuiKlainental finuiito, and tlic yoiintier .set is sometimes
found in the i<;tieousand ])yrocIastic rocksof the |{aiiiparl scries. In
many places it has been noticed that the yoiin;rcr set of ipiart/. veins,
which, on account, of their unaltered condition, can be iiiori' easily
studied than fhe older set, grade into acid dike rocks, such as aplitc.
From this and other considerations, a theory of the formation of thu
auriferous veins has been forinulaled, namely, that they re|)rcseiit,
the linal stage of a gradual process of rock consolidation, the rocks
representing the other stages being found in the same districts. 'I'lie
gold is supposed to bo a nearly universal const it iieni of rocks, and to
lia\'e been a ])artr of the general magma; ami its abiindaiice in some
<iuartz veins is supposed to be due chii-fly to the free circulation
attending deposition, and perhaps partly to some special adaiitability
whicli gold may possess for solution in the siliceous and alkaline
fluids which are conceived to be the final residue of rock <'oiisoli<lation.
In mail}' places the rocks have been sheared, especially tilong cer-
tain definite portions, and thus slie^ir zones are produced. In some
of the formations, notably the Hanijiart scries, there has been no
regional scliistosily, and therefore these local shear /ones traverse an
otherwise nearly massive rock. The zones have naturally been
selected as channels by cireulating waters, and along them a con-
centration of metallic minerals has often been elTected by the deposi-
tion in crevices and interstices of materials held in solution. Thc.so
18 GEOL, PT 3 US
',)y(] (il'.OI.OtiV or THE VIKON O'lI.Ii IMSTRrCT, Al..» KN
(•((iii'i'fil iiiliiiiis -ir iiii|iiri.'iijil icni^ may in soim- i'aM'> I'lniiiiin l'"!'1 .iihI
.sil\ (T aliiML wilh iillicf iiiitals.
'I'lii- iiii-l>> 111' III)' Karii|iarl m lir,-. have hi'i'ii i'\|mi^"mI t>> aiiii<>-i|i|i<'Vic
crusinii >iiicf till' I iiiic 111' ilic riirnni inn 111' tin- .Mi^^illll <'r<'vk sciics,
.-'III! pnilialily lii'l'iirc. a>- sIkiwm liy i-iiiii.'liiini'i'aIcN. 'I"hi> MTii-h, liiiw-
fvt'i'. ami I III' iiMi'i' i'iirU> wcri' lirst i'\!icim"I Id arlivi- iTiisimi siiIim*-
i|iii'iii In 111!' iMisi-Ki'iiai ii'\ iiliiiiiiii. .\i 1 lii?» |iiTiiiil 1 III- wcariiiir away
III" till' ^ iikmi ;;«•»;. lii'liiif rxposcd liivnlil rocks in a ^H'litTai limail
Ik'M, wliii-li cxii'mls in a mirili\M-sl ami sinilliwist 'dii linn I'ur at
least a lliiiiisaml niili-s. SiiliMMiiicnt crosiiin lias ii|MM'at<-i| unly ti>
liiiiaili'li tills /mil', vvliich al picseiil i-inslilnti-s ilii-^olii licit ><( l' .■
\'iikiin ilisti'ici III' Alaska ami llri sli ('iii',::it>ia. Kvcv since ilie
liei:iiiniiiLr <>l" llie pcrind nf active irnsiiiii '.lie ^'iiiil-liearintr ijiiaitz
\cliis ami iillier metallic acciiiiiiilaliniis lia\e beeii I'nkeii up ami c ir-
I'leij away liy watei's with nilier im-k dftriliis. lunl from tliis lieicio-
:,'eiieuii> mass the Hold, lieiim lieiivicsl, has always l:ad a lemloiicy to
cuni'eiit rate incclianicallv al llie hiittom ul' any deposit. 'I'liiis at the
picseiit day it N t'oniid In tin- I'olloiiis of the j^iiiches and on the hats
of ri\ers. Tlie olilcr acciiiiiiilatioiis of detritus also ciuiiain coiiceii-
tialed ;rolil. ami these |iriilialily riirriish some sU|i;ilies to the luore
it'ceut acciiiiiiilat ions.
I'UM ri( .\:. AI'IM.Il ATlo.NS OK ( ilCOI.i io!( .\ I. I'ISUVI IIM.ES.
'i'lie i;oli| 111' the \'iikini district is < liiclly derived Iroiii nwn'.z veins
whitdi arc I'oiind iiuisl aliiiniianlly in t lie schists of t hi' l''oi'tymile and
the jiireli ('reek series, alllmu^di not iiirreijueiitly in t Ik ii:iieiiii> and
pyroclastlc rocks of the |{aiii|iarl sories. It is also derived, althouuli
to .'t far less ( \."'it, from i-'ipretrnated shear zones, which occur
cspcciallv III the Katiii)ai't .scries. Of the ijuart/, veins om >et is
sheared ;; ! one iiiishcared. 'I'lie lirst is 4lilVK:iill to follow . i.ir the
veins arc liinkell ami liolipersistclit. The \ ciiis of the secoii •set ar<'
often persistent ami wide, and in .some cases may lie mined p 'iiitaliiy.
1 mpieyiral.ioiis alonir slic-ir .-.oiics aiay a'sii In Mime cases lie siillieieiitly
rich In illelallie iiiliici;ils lo I'orm ores under favoralilc ciiiditioiis;
and the rock in the rei;ioii of these shear zones is oft"ii iinlaiilted, so
t liat I lievi- (lie liiidies may lie expected to Ik' <'owipavai i ve'y persistent.
'I'lie i|ii.irl;'. veins at !• reeled with i!i!::'^, chiefly- I i;;li: -colored
cr\ N!;;lllnc rocks, Mich as granite an ' .iplitc This should 1m' kept in
mind in ;irospectin^. and aurli'eroii.-^ \ciiis nuiy lie luoked for in the
schi--ts near .lie '''kes. In some ca.scs, a'tlioiii.di not so comiiiouly,
I lic\ iii.'iy also lice 111' at some oislaiicc from a dike
Thcsi icold liearinii' rocks form ,i detiniic hell, extemlliic tti a p-noral
way from the !,oN\er {{amp.nls of the ^■|lk!lll and liclow in |)easc Lake
and oilier iiiiniiii: dist rid s In liritish ( oliimliia. .• distance In a straiu'ht
line nf aiioiii a ilioiisand iiiiies. of this disiaiicc. Iiio nr .'i<mi iiiiles j.s
in .Viiiciiciii icrrlini \ . 'I'ijc width of the licit \aries chiellv «itli tiie
SIMMAKV AMI I'liVcri. Al. AIMI.ICA I I< .Ns.
;wi
1
liiiih.r foldiiif: wliidi 1,,,^ ;i<-.niii|i;,iiii-.| the L'Kjiirr jili.-ali-.n-.. In iIhh
Ik'Ii !I(.I (.Illy Ui.' .;,'ol<! iH.jiiiii-: v.mii> hut i1m- li.l,. ..i i.1;i,-.-i> iir.- Imih,.!.
Tlii> i> iialiirally llic .ms.. since ih.- u''>l<l in ili.s.- pla.-.-i-x i.s w,,im .mt.
iif lli.'s.iliil nx'ks. ll is<'s|(c.ially Iiut- thai tli.- ii.-|, :r,i!,.|, ._r|-a\,.i> n,.,.
in Iliis licit, an.l also the must paying' l.ar ^'ravels. ,iltli..ii(;|i jm.- -..I«l
in some cases may 1 arrieil snmcv. hat iiiilsiii«. ,,| )l„. 1h.|i. ami rnav
lie siil1i('ieiitl>- <-ciiicciitiatcil in l'a\ maiilc sitiia! ii.ns to |iay I'-.r wasliinir.
Till' Hirch ( leek. thf l'oii\ mile, and the K ioudikt- (listriCH are all
in this hclt. ami are all in the schistose rucks, an.l in \U,-^.- r,„.k^ new
<lc|iusits .^^ value may lie looked tor. >uiim> plac.r .li!.').'iii-s ,,f vuIum
nia.v alsu lie found in tln' rocks o| ih.' Itampart series. I.ul as a riil«
hijrher horizons at.' |.iiihal)ly liarreii. saM- in e\c.-pii,.nal cas.-s < ..n-
jrloin.' rales maili' iipul' the dftrittis rr-..m ilie schistose Uiich ( r.-ekand
Furtymili' roi-ks sliuulil in- ])ruspecteil. ho\M'\.-r. since the\ iiia\ prove
to lie l'(.ssil plai-ers. .ViHMcnl irraM-ls l\iiit: aUiv.^ ,he pr.-seni -.tL-aiii
<'h;»iinels sho.ild also lie kept in iniiirl, i'urthe.\ iiia> in plac- cuniaiu
siiHicii'iit ;,'uli| to lie prulilalily iiiin.'d.
The ([.lesliuii as to wh.'lhera .■ertain di'posit. .'ither pla.-.-i ..i Iw-d-
ioek, contains cnoiiirli i;(.ld or metals to n-niler ii proliintil.- tor work-
ing: is one which can 111' solved liy no universal rule. Aile|M.sit whicli
under crlain circuii'slalices is < vtrem.'ly valiiahh- may umi.'i ..tliei-s
he etitin-ly Worthless. Tile circumstances w hi. -h miisl Iw lak'-n into
euiisi.leraiiun are: Cost of mitiiii;:, ease of separatiit<.' iln> m.Mals
lidiii th.MMi's. faeilityaii.l cost of i ra;ispuitatioii. ami niiint'roii.soth.-rs.
The i|iiesiion as to wh.'ther any ilep.isit ur an.\ in in my: district in ;.'i'ii-
eral will ll III.' prolilalile .-an lie only partly suIm' '. liv iieulu;;v. fur
the l-cst .Icpemis ll[iuli other scienci-s. .1 the pri-si-nt . i'lie ( Is'."'.) lalior
in Alaska is worth «1 an I r, ofiKi a da.\ , and this irjves a fair hlea
of the a verairi ""I of pi-oiliiet iuii of placer irolil, which is two or three
times that in more ac.'issihle countries. In this rei.'iuii. ih.-refure. a
]ilacer di'posit in onler to repa.v workiiifr iiiiisl at pies.-ni I..- ilii..' ur
four times as pruliiahlc as a deposit in must other places. |n iH-d-roi-k
mines the c.\ pen s.'s would he prop.irti.mat.dy iiiiich ^r.'a'er. sin.-.- mure
e\)iclisi\(' i'iiui|)meiits. iiiacliiiiciy. .-tc.. iiiiisl lie pnn i.led fm the piu-
.li'ctioii. an.l pr.ilialily facililii's for t ranspoitat ion of iln' ur.' fur lony
ilistances. ruder exist in;,' c.iii.litiuns. iherei. r<-. lli.' pi. ilialiilitv uf
lie.l-fuik iiiin.'s siillii'ii'iit ly I 'I'h to iepa\ work iiu' is no! i;r.'at. Were
these coiiiliti'itis y^rcatly iinpr d. however. p,i\ iiiy mines in the Im-i1-
i.i.'k iiiiyht lie foiitnl, ami .'oul.l hi- wuike.l in spiti. uf tli.- s.-vere .-li-
tiiatic .'onditioiis. The^iro<liii'tion at pi.'seni i- I'litirelv from pla.'.-r
.l.'|iusits. which are prudtalile in the t'ac.' of the u'f.'al "lis,ii|vantai'"-s.
ami with lictter eondilionsa vast amount of aiiiileruus fiavcK nuw
Useless wuiilil lieculiie \allialile.
Till' mineral resuiirccs must remain for an inihiinite peri.i.| .-.•mpai''
!iliv«'!.\ Useless, iiiili'ss sum.' means 1..- taken fur spe.-dier ami .-heap.'r
cuiiimmiical iun heiween ih.'iiuld n'L'i.iti ami the uiiisid.- w.irl.l As
'AHS
iKoi.oiiV or rnr. yikon (.oi.d uistkict, ai.aska.
I*
ii"!
Ilu> foiiiilry itself pniduccw hfirtlly cnonfjli food to support life, all
pr(«\ isioii> arc now brousrlit from San Kranciseo or Scaftlf, tli>' usual
rouh- licinj: hy sea to llic mouth of tlio Yukon, ami tlicncc up tlio
river to the iriiiiin;,' ilistrict, a ilistanee of over l.ooii niiifs. This
nuikcs supplies so c.vpcn.sivc that unless l)elter- transportation is pm-
vicleil tl ountry will prolialily lie aliaiuloniil as soon as the rii-hest
plaeer WDikinu's have oeen exhausted.
l'"iii' opi-niu},' up more rapiil 4'iiiiimunieation, some route from the
<'oiisl in llie \ieinity of .luneau seems most feasilile 'I'he waters of
the^ukonare na\ivMlile for river steamers of li;,'ht draft up to the
head of Lake Umleman, exeept for twoortliree jilaees where short
rapids exist. Two or three steamers built withdu nsideration as
to the ehaiaeter of that part of the river on whieh they were to ply
wouhl I'orm a complete eonneet ion helweeu the head of Lake IJnde-
man ami tliei,'oJd reirion dui'iuf,' the lo;irorlive months that the river
i> util' I'll/en. 'I'he head of Lake Mnilenmii is only about -j'l miles
from the lutvi^able watei' of the sea. Another measuie whieh wiiuhl
1m' of ,u;reat value would be the building of a waj,'on road from the
eoast in the vicinity of .luneau to the .junction of the Lewes and the
I'elly rivers, whi<'li point is below all obstructions to navifratioii.
This road should be built a<'ross some of the mountain passes other
than iheChilkoot. whieh is nnw used, for the Chilkoot, aIlliou)j;h short,
is hij;lier than its neighbors.
f
< I! A I'T K H IX.
MK'III«H» Of MINING.
ii.vi: li|>.i>lXfiS.
In baiMlisrsin^s fho inatorial wliidi da-, to \>f \va«l)o<l oonsisu larsrclv
ol'cuai'sc, run in I |ii'l>lilcri: ami l»y whait-vcr pnK-i'>> ilii-i:(il(| i-.i'\i laiMfil,
these ](ehl)les ar-e separatfil fip^t: tlii-r<- tlit-ii rciiiains tin- liiiei- male-
rial, wliicli is iiiaije up iif tin- hi-avier •••.ii>iitiieni>. nf the same iipek^.
I5laek saiul, wliicli ei>iisist» <>f iiiairtH-til*-. hematile. ami sdinctimes
(rali'iia. is nearly always almii'lant. aii<l in s«inie ili;;L:inir* tlieie is a
"y;ray sand," cnnsislinir mainly of Iwavv »par: anil when, as in I'lnly
Mile ( 'I'cek, the stream flnws thr<iii::li x-hisis. ^rarnets derived t'l-nm
these form a ver>' imiHirlant part of tlie residue. All iliese. Iii)\\e\er,
arc still lij^hter than ;;i>id. and an- event nallv separatid trom ii liy
menus iif their inferior s|(«H*iti«- ^nivity. through the a;;eii(\ n( walei-
apiiiied in various ways, or linally l»y air applied l>y a liellows.
I K.tbLIMi.
The u'olil |ian. whieli is worke<| liy hand, i- Ilie simplest i-ontrivanee
for separalinir th4' ;rold from the ;rnivel.s. The next eoiitrivaliee ;;i'ii-
prally made use id" is the i-nidl«-. whieli is eonstrneted on essentially
the same patterns as eradles .vhii-li «er«- us«h1 in Califitrnia and .\us-
tralia in the earl.\' days of plaeer mining;. The eradle eonsists essen-
tially of a lonjx. narrow \n>\. witli an np|MTand a lower eomparinienl.
The (liKU- of the u|>per eompartinent i« pn-ferjibly made of metal, and
is riddled with holes of convenient size. Intotliis upper compartment
the i;ra\ els arc sliovided, and the whole <-ontrivanr-e is mo\ ed hai-k and
forth upon the rockers on whicli it stands, and from uhi<'li it <lei'i\cs
its immo. By this shaking! the jrntvel is sift«'<l; the liner material
jiiisscs throunh the hole>, into the lower coiii|tiirt meiit, while the coarser
material, whii'h contains little or nopild. pas-ses out of the box as use-
less ruhltish, or ■" tailinj;." as it i« technically called. The floor of the
lower comifartmeiit is, in its sinipl«.*>t form. an inclined plane, tic sur-
face of which is ronghentMl or corriisfiit*^! in various ways, such as liy
the use of cleats or wo«Klen " riffl***." ••orninatol metal sheet. iii;,.
other devices. A favorite metho<l of olitaiiiin^ this result anon;; tho
miners of Alaska is by thi- ii.h*- of car|MMin^. of coarse, spongy wejive,
such as ordimiry ta|>estrv. r|>oii thi;* rou;:hened surface the line ;;old
lodges, while the lijrhter material is <-arri<H| out of the box by th(>
,".:i(t
(iKOI.OOV OV THE YfKON OOI.O DISTIMCT. ALASKA.
slifiiin <>( water. In llic I'dlcction of tlif fun- tf<>l<l wlii<-li is Iluis
caiiylil iniiali.'aiii,ili(m with <|iiirksilv<T is usually n-sitrl.-d to.
Ill sdiiii' l>ais Ihi'ii- is ruiiNiilciaMf iMiin-fiiiratioii ..f irold. ami wlicii
tiic ii\fr is sutVicii'lillv low tiicsi- ai-i-iiiiiiilalinii- ai<- workol liy llic
iiiiiicis: hut ilic (•(iiiiparativfly small siz»'->f tlif<li-|Hisits. ami ilic fact
that tiny ail' ixiHisfil only an uncertain len^ttli of ti liurinj: low-
water, leaii to tlic necessity of nsiii;: llic Hiinplest appaiat lis. ami so
the era<lle is irenerally ntili/<><l. [n some ca.--> Uie liar ^'ravi-ls are
slniceil in tlic same way as the ;rnieli ;rrj»vels. the water Iteinjr raiseij
to the licail of the sluice ill llie liiK kcts of an iimlerslioi water wliecl.
(ifl.l II DK.iilXl.S.
In till' irnl<'lies the conditions are .-ntin-ly "lifTereni. since the anionnt
of water in I he si ream lied is usually small and can !m- .-asilx di\ cited
if iiecis.sury, and the tiold oecui-s in a small cJiannel in the narrow
gravels. These ^nhdi irravels vary in thickness from alHiut :i or I iVct
to L'li or :;o feet. Their upper parts, however, an- invariably liarreii;
the ■:old is all :' mml I'onccntratcd at the Inittoni. wliatexcr the thick-
ness of the upper ^.navels ma\ 1«". The ;:nivcl w liich contains jjold
ill wdi l^alllc■ '|U""li'.v is tci'hnieally ealle«l •* pay <lirt." It is usually
not more than :i or l feet thick, and from that thickness it runs down
to a few inches or less. Tin lied-r"M-k itsolf.it the junction with the
era\cl iisuall\' contains iroM, and oftcti n-pays working: foi- :.' or :!
feet down. ,iiid sometimes the richest dust is found in thi« p;irlly dis-
intev'riited schist. In the thin layer of [wy dirt which ic-i- upon the
scliisi the ^old occurs ill particle-^ di-.-.cminate*! throiiLdi a i.'r;i\c| con-
luiniii^' many lar>;e and little-worn fra^'iiients of .st-liisl and (piarlz.
SI III INll.
W'lieii the oxerlyiiiLr harreii ;.'r,ivels an- not t<><> thick they aro
stripped olV liy shoveliii;; and the pay dirl is laid luire. Then a loiitf,
sli;:lilly inclined lioiiy:h, c.illed a sluice, which is liuilt in si'ciioiis of
eipial len;rth, so as to lie easily taken d«iwn and tnin^pone-l irom one
plai'e to another, is <'onst riicted of Iwiards. The lM.ard» for this pur-
pose aie cut liy the miners from lo;:s with the aid of the whipsaw.
Tlic ilitTeretif seetiotiH of this troiijrli or -luiei- are <'.illed lM>\es, and
when these sluice ho.ves are ;irraiu.'ed con-ecutividx aiic) in |iositioii
coinenieiit to the deposit of pa> dirt I he water Mow inj; in the bed of
the ^tilch is partly diverted into them. ■»<■ that a <-<>ntinuous stream
Hows Ihroiiirh the sluice and cmptii-H at ii^ lower end. The jiav
V'taNel i>. then sl|o\e!ed into the lMi\es. mostly into the Up|M>r ones, so
that the ;:ra\el will lie carried a^ f.ir a-> |»issihle U-forc Wciiit: ihiown
out. The current is so rc;rnlatc<| that the liner ami li;:hter material
and the sinallor uravelsare itnmeiliately c.irrn-«l out of the trough and
deposited at its end. while tlie larye |Mdil>lcH and the heavier small
imrticlcs sink to the hottoni and advance inoii- slowlj. The lar^iest
METHODS OK MININO.
391
Jrtou*^ an- i<-iniiv('(l by a iniiicr wlio sianils n-ady witli a slmvi'l i-i
••lear lh<' )m<\.-> lit' siH'h inriiinlifainM's. Tlif lii'a\ii'.si nf all tlic niatr-
riab» i» tIi«- ::o1<1, wliirli rniil> iis way tn the Ipniidin nf ilif ^liiici'
To |in-v<-iit lliis fniiii i->caiiinir a scvii'> of slal> an- iiiMMlcil in tin-
but loiii "f <<iic iir inure (if ilif liuxcs al the ciid uf l In- sliiici'. ami llif>.i'
slaU*. or •'riffles," as ihcv arc calh'il. alTonla l(i<liriniMit lnr iln' InaviiT
p«rti<-l«->. The fifllcs art' usually plapod jiaralli-li" ilic >i(ic?. ni' ilu-
box ami fv»iinwl<'<l by cross-cleats, allln)iij,'li various uilicf patterns
art- ••iiijiloyc*!. At statcil inlefvals tlie cui'ieiit ol" wain- i> tuiiied uiT
fmiii the sluice, the slats or lilllcs are taken up. ami the lieaviei-
malTi;*! which has aiMMinuilaied i> caret'idly collecteil Tjie aicmini-
latioii ir. \erv rich in ;rold, and also cinitains inairiielite. Iieiiialile.
liiiionilc, galena, and i>yrile, as well as many t'lairnienis of the laiei-
hfavv iiiiucrals. This material is ticin-i'ally waslicil by liami in a
}ri»l«l {Kill, thus sceutinu a irreatei- concentration nt' tin' i.'"ld. but
tht-n* still n-iiiaiiis some pyrite. iralena. liemaiiii'. and maLrnetite.
whii-li can ih>l well be >eparateil from I ne ii<..>\ b\ wa^liinir. 'I'lie
matriictic iron, which i-. known as "black sand" by the miin'i-.
is i-x1ra<'1c<| with a small hand ma'.'nct. an<l the otln!' niiiicral-
an- -«-|Kirat«-<l from the irold by blowim^ i In' aLririciiatiun with a sinall
haii'l )m-1Io\v-. Tlie pyrite, hematite, and ^'ahna thus blown nut aie
ni;i~i<-<l. uroniid, and ]>anned 1<.\' the more ccunomicd mim'i>, and
Ilifii yichi considerable free i^old.
It i> iiii|Hirtaiit in l he cousin MM ion nf shijce-- l lial the ;.'radc be accu-
ral*dv a<lju-«ie<l to the birce nf t he cnircni «hich llnws I hrouiih it and
fti the leiii.'lh of the bn\. If tin- tirade of the sluice is too siiial!. there
i* a c<in«taii1 tt'ii«h'iic.\ to dojr. and the accumulated iinid will be a-.>o-
a-iatol Willi a very lar^e proportion of valueless diri. uhile if the
;rrai|«- is t<Mi irrcat inin-h vahnilile material may be carried oil" at tin-
••lid of the liovo and cleposited as refuse or " lailintr- " .\> an i-xanrplc
of thi» latt<-r mistake it ma\ lie mentioned iliai the lailini:^ u hieh
liav«« l«f«'ii aaviiiiiiihitcd by one miner arc often >ucc e^viull^ lewaslicd
by another.
Ill ItMNi. AMI IIUIITIM;.
The lalnir of removiii}.' the barren ;;iavel which oveilics the pa\-
ilirt i> vcr\ ;rn-al, but ordinaril.v this is nndeiiakcn when the thick-
iiesj. is not ctiiisidcrable. With im-rcasinu: iliicknessa point i> sonii
r«*ai-li<'<l ulicn* the tusk of removing' it bccoiins so formidable that the
miner will not make the altemjil unless he believes that I here in rich
|ia% <Iirt )M-tieath. In this e\cnt the practice is ado]>led of siiikin;,'
shaft.o throiijrh the barr.-n material tn the pay dirt and extract inji
this !«<« dirt hy means of lunnels or di'ifts alons.' the surface of the
)ie«J-r<M-k. This method of workiiiy; has been adopted only lately,
but proiiiiws to lie \ery inipnitaiit. The ordinary melhoiN of sink-
ing, ilriftiiijf. tiudK-ritiK, stopinu. etc., ha\e bei-n peculiail.\ modilicil
iu the Fortviiiile district on account of the excciitiniial chaiai'ier nf
3!f_»
fiEOLOOY OK THK YUKON GOLD DISTRICT. ALASKA.
tlic cliiiiati', and these iiiiKlitiealioiiH liave spread from this dislriet
over llie rest nt the fjold ilijr^'infrs. Owin^ to the severity and
len;rtli of the wiiitei-s the ^Travels are frozen dnrin;; seven or eifjjlil,
inontlis of llic vear. The miner who desires to sink a siiaft waits
until llie cold season arrives and then sini<s throu^rh the frozen
gravel, wliieli is so firm that the simfts or drifts do not need tiin-
Ix'rin;: foi' the salve of support. In sinkiny: or drifting, instead of
employing powder and piek. as elsewhere, a small tir-e is built at the
bottom of the shaft which l> being sunk, or at the face of the drift,
which is JM-ing run, and thus the gravels are thawed out for some
distance and can be easily shoveled up and taken to the surface. It
takes a surprisingly small amount of wo<Mi to run a <li'ift thi'ough the
frozen gravel fora longdistance. In this way the i)ay <lir1 is extracted
and accumulates on the surface until spring, when it i.s shoveled into
sluices -Md ilic;;old is separated by washing, panning, blowing, and
.■::;algamation, in the mariner previously described. One large cham-
ber or ••slope" thus excavated in the gravels on .Miller Creek, in the
Kor'tyinile di.strict, is said to have ineasnr'ed til by [}•> feet, and 1!»
feet in height, with only S feet of barren gravel iK-tween it and the
surface; and yet this stood lirinly until spring, when the gr^avels
thawed and the slope caved in.
■s.
^t