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From ,'/, 
 
 • (U'AKTKKrv JorR'.Ai, of the Guot^ootcal Society for 
 Fchninri/ 187'S.j 
 
 c 
 
 y 
 
 7 
 
 On the SuiMiRiTcni, (jiiioLooY of British Columbia. liy Gkorgi: 
 IMkkchk Dawson, Esq., D.Sc, F.G.S., Assoc, U," INf., Assistant. 
 J)iroctor of tlie (Tealo,i>:iral Siirvoy of.(yanada. 
 
 [I'LATK v.] 
 CON'TENTS. 
 
 1. Outline of Pliysiciil Geogrepiiy. 
 
 2. Vancouver T.sLand and tlie Const. 
 
 a. Gliiciiition of Ruck-.surrjices. 
 
 ^K Superfii'iiil Depusits. 
 
 c. Observations n(jrtli\var(l in tlie Strait of Gooriiia &c. 
 
 .'}. Interior of British Columbia. 
 
 a. P "iiition and Roi-k-polishinnf. 
 h. .S cperfieial Deposits;. 
 
 Preglaeinl Gravels, 
 
 Unmodified Drift. 
 
 ModiHtxl J^rift. 
 
 Shore-lines. Tervaoe.* and Benches. 
 
 Moraines. 
 
 4. Mode of Glaciation and Formation ol' the Superficial Deposits. 
 
 TriE following notes give, in a siim'.uariiied form, tlie chief observed 
 facts of tlie (ilacial period in Briiish Columbia, obtained during the 
 season's work in that province on the Ceological (Survey of Canada. 
 Tliey are oftered as an extension to the Pacific coast of the observa- 
 tions carried in a former paper* to the Rocky ]\rountaiu.s. 
 
 ] . Outline of Physical GEOGRArny. 
 
 For the purposes of this paper the eastern boundary of British 
 Columbia may be regarded as coinciding with the Rocky-Mountain 
 range, from which the i)rovince stretches westward to the Pacific, 
 including Vancouver and tlie (^ucen-Charlotte Islands. Houthward, 
 the 4!)th parallel separates it from Wasliington Territory and parts 
 of Idaho and ^lontana. To the north the Province-line is drawn on 
 the 00th parallel. The area of British Columbia is roughjy com- 
 puted at 330,000 square miles, its cxtemc length, fron) corner to 
 corner, being about 900 miles (see Afap, PI. V,). 
 
 The Rocky Mountains, many peaks in which surpass 9000 feet, 
 are defined to the soutli-east by a remarkably deep and straight 
 valley, in which are considerable portions of the courses of several of 
 the largest rivers of the country. (South-westward, beyond this great 
 valley, is a second and broader mountain region, called by various 
 names in different parts of its length, but which may be generally 
 named the Selkirk or Gold range. Many of the summits of these 
 mountains are scarcely less in altitude than those of the Rocky Moun- 
 t ains ; and in many places they ap]>car to be broad and platcau-liko, 
 
 * *^iiiiit. Journ. Geol. Soe., Nov. 187 ">, vol. xxxi, p. (JIK'}. 
 
 a 
 
5)0 
 
 OEOKOE MKllCKU UAV'SON ON TiJE 
 
 with (t(>m])iiriilivcly iiarrov; iiit.tvvc'iiiiig valleys. Nearly parallel to 
 these two ^rcat raii<j:e.s is the Coa>it or Cascade range, in which the 
 average altitude of the hij^'her peaks is hetween (!0U(> and 7U(»U feet, 
 while Honie exceed IHMIO feet. A fourth ranp;e may he traced, in a 
 ])artly submerj^ed condition, in the mountains of Vancouver and the 
 Queen -Charlotte Islands, lietween the Coast range and the Selkirk 
 or (liold range lies the great intei'ior plateau of Ih-itish Coliinihia, 
 ■with an average width of 1(JU miles, and a mean elevation of ahont 
 ti'AH) feet. Its height, on the whole, increases to the south, while 
 northward it falls gradually towards the cluster of great lakes, and 
 the low country of the I'eaee-Uiver valley. This ]dateau region has 
 over a great part of its area been covered by wide-sjiread Hows of 
 basalt and otlier igneous rocks, in the latter Tertiary period. It is 
 now dissected by deep and trough-like river-valleys, into most of 
 which water standing at iiUUO feet above the present sea-levcd would 
 penetrate, dividing its surface into a number of islands. In some 
 jdaces the jdateau is ]iretty level and uniform : but usually it is only 
 when broadly viewed that its eliaracter is a])])arent. The best pub- 
 lished maps of British Columbia but iin])erfectly indicate even its 
 grander physical features ; but I believe, from information received, 
 that the north-western end of the plateau is blocked by high moun- 
 tainous country, formed by a coalescence of the three great ranges 
 in latitude 55° 30'*. Nearly coincident with the litth })arallel is a 
 second transverse mountainous zone, formed in a similar way. which 
 may be C(msidered as ])ounding the plateau to the soutli, though tra- 
 versed by several great river-valleys, of which that of the Okanagan, 
 in longitude lli)° ;i<>', is the dee])est. 
 
 No modern glaciers hav(! been seen in the Rocky ]i[oantains, near 
 the 4!)th paraUel, though much snow lies among the higher jieaks, 
 and northward, about the sources of the Saskatchewan, true glaci( rs 
 ai'o found. It is probable that S(mie glaciers may also exist in ])arts 
 of the Selkirk range. In the Coast range glaciers alxmnd from the 
 4!)th parallel north-westward. To the south they are summit - 
 glaciers, but northward, about latitude 51°, filHong valleys, and still 
 further north are reported as coming down nearly to the sea-levol in 
 some places. 
 
 Three main structurc-directioufi serve to account for the greater ])art 
 of the depressions of the surface now occu])ied by rivers, lakes, and 
 the fjords of the coast: — J , a north-Avesterly and south-easterly series 
 of hoUows, de|»endent on the general direction of folding of the rocks 
 of the country ; 2, a north and soutii, or meridional series, due, where 
 I have had the opportunity of examinnig it, to systems of parallel 
 cracking ; 3, an east and west, or transverse series, occui)ied by many 
 lakes and rivers, but the cause of which has not yet been determined. 
 There are also traces, indicated by valleys in some ])arts of the map, of 
 structure transverse to the main direction of folding. It is, of course, 
 not int^'iided to ultirm that the causes mentioned jn'odiu'cd lh(>se 
 features directly. l)ut merely that certain struct urallines of weakness 
 
 * t':il!i'(l (111' Peak Munut.iin>^ nii old iniips. 
 
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 I 
 
SUl'iiUKICl.U, OKOLOOY ()!• UKITISU COLUMBIA. 
 
 91 
 
 tlius iiulicatcd were those on which crodiug agencies afterwards 
 -sliujied the country. 
 
 The arriingcment of the lakes in British Columbia, and their long 
 I'ivcr-like forms, arc very reu-.arkublo, suggesting at least the action 
 of glacier ice, which, tliougli it may i)ossibly have formed rock-basins 
 in some ])laces, has generally, I believe, been instrumvutal in causing 
 Inkes ))} the arrangement of the drift-material in preexisting hollows. 
 To the mode of formation of lakes in British Columbia 1 ho])e, how- 
 ever, on a future occasion to return, when more information may 
 have been collected. 
 
 The fjords jmkI passages of the coast, while <|uite analogous to 
 those of Scotland, Norway, and Greenland, probaldy surpass those of 
 any part of the workl (unless it be the last-named country) in 
 dimensions and complexity. They also ap])ear lo differ from those of 
 Scotland and Norway in their narrower and Tuore parallel-sided forms, 
 and in tlie height of the walls which bound them. They are, no 
 doubt, the valleys of rivers worn out when the coast stood at a 
 greater elevation, and are all continued inland by dee]) gorges, in 
 which streams still tlow. The iipper end of each inlet usually shows 
 a sm.all area of low swampy land, formed of material brought down 
 by the river, it is continued seaward by a shallow Hat for a short 
 distance, and tiien dips steeply down, like the front of a terrace, into 
 deep water. The arrangement of the material shows that the waters 
 of the s(>a have long maintained nearly tho^'" ])resent level. In fol- 
 lowing the inlets down they are found t be very deep, often as 
 much ivs loO fathoms, and sometimes over 200, though in most cases 
 they arc marked on thi? charts as 50 or lOO fathoms and no bottom. 
 t)n arriving at the mouth of the fjord the water shoals — ^just as de- 
 scri1)ed in Scotland by Mr. Cieikie. This 1 believe to be caused by 
 the banking-up of sediment by the tidal currcMi^^s, which run with 
 great fury up and down the coast, but tlow with decreased power 
 into the sheltered tjoi'ds. There may be instances of true rock- 
 basins ; but the exact evidence required to put this (luestion beyond 
 doubt has not been obtained. In view of the deep and narrow 
 .;hasms or canons, in which many of the western rivei'S now run, 
 and the difficulty, even if the whole outlet of a fjord is seen to be 
 over rock, of proving the non-existence of drift-blocked channels in 
 other directions, it is well to be cautious in the assumption of deep 
 rock-basins when other causes quite competent to the explanation 
 of the facts are at hand. 
 
 An elevation of the coast of British Columbia to a heigl't of 150 
 feet above its present level, would now convert the inlets of the 
 western part of Vancouver Island into a number of dec]) lakes, lying 
 among the mountains, with their lower ends stretching out on a level, 
 as a gently sloping ]»lain of detrital material, over which their rivers 
 woidd seek the ocean. The analogy of this state of aflairs t;0 that 
 now obtaining with the strings of lakes foUowing the slopes of sonu^ 
 of tlui mountain-chains of tlu- inierior, will be evident from a glance 
 at the map. 
 
 The highest mountaiu at VanooU'cr Island (Victoria Peak) attains 
 
02 (iVAtH*'V Mi;n( i;i< daw son hn ihk 
 
 ail I'luvalioii of 74^4 feet, while theic is it considerable niountiiiiioiKs 
 ai'ca ill the CLMitrc'iit' llic ishiiul, wliicli .surpasses lJ< MM t feet in avera^M- 
 iihitutle. 
 
 1'. ^'A^•« iir\ r,i{ Isi.anh \n'ii tiik Cdast. 
 
 (1. (i'IiicIkU'i'ii. of Riivh'-tiiirfdCiH. 
 
 Tlie glaciatiuii of tlie rocks in the vieiiiity of Victoria. Vancouver 
 island, is so well marked, and ])rese!its it s(4f so iniinediately to any 
 one arriving- in llie locality, tliat it has lieeii lueiitioiied by most 
 writers on the country, and has heen made (he subject of remark 
 by several ficoloyists*. The rocks ]protru(lini!; from the soil, and 
 ]irojectinji' ahjiij;' the shores, are generally conqiact, coarser or tine- 
 ^••raiued diorites and I'elsites, bedded or intrusive, which, while oiler- 
 iii^' throat resistance to abrasion, arc well suiti-d to jireservc i'ornis 
 impressed on them. 'I'he direction of the ice-markiiifis here has been 
 variously jfiveii — a circumstance arisiii*;', 1 believe, chiefly from a 
 want of attention to the maji'iietic variation, and the isolated 
 character of the observations made. I am now. however, in a 
 position to state, as the result (»f several hundred observations oftlie 
 course of the striatiou, that lint one g-eneral direction of movement is 
 indicated in the whohi soiith-ea<terii peninsula of N'aiicoJiver Island, 
 the averujie beai'iiifi' of which is about S. 11° W.f. and from whicli. 
 except under certain special local circumstances menti(>iicd below, 
 there is schh)m a departure of more than a few deii,rees on either 
 ^^ide. At Sooke lliver, fifteen miles west of Victoria, the only dis- 
 tinct <;n)Oves seen have a course S. 1^ W'.. which aurecs closely 
 with the above avera'i;o direction, but is also parallel with that of 
 the hills lioundiii^!; the river valley, (jiroovinir and striation are 
 e(]ually apparent at all idevations in the neiuhbourbood of Victoria, 
 from low-water mark upward. The summit of Blount Douglas, or 
 Cedar Hill, a rocky eminence (IDC) feet hii;h. is quite distinctly 
 jflaciated, the direction beinji'. as nearly as can be ascertained, due 
 south. On lo(diin<ij northward from this hill on the wide expanse of 
 the Strait of (/eorgia. no hii;her land a]»pear.-. for about fifteen miles, 
 and then only as summits on scattered islands. Suitable hicalities 
 for observation at greater altitudes are wanting' in the vicinity ; or 
 ice-AVork could no doubt be traced to a yet higher level. 
 
 Kocks which, from their prominence, have been exposed to the 
 full force of the ice, are generally grooved and fluted in the most 
 remarkable numner (fig. I ), have been worn into boat-bottomed 
 shapes, marked w ith parallel hollows often a foot or more in depth 
 
 *' Ttic gLiciMtion of till' sdiitlioni |>;irl of Vancouver Island lias Iiccti rcfcn'od 
 til In tiio t'dlliiwiii!:; gi'iitleiiicti :- If. ['ancniiau, "(Mi the ficuldgy ol' tlicSoulli- 
 eastern part of X'ancmiver l.slan<],'' (Jiiart. ilourii. (ieol. Soc. vol. xvi. ]). I'.IS. ('. 
 FortiL'si, M.D., ', Prize I'^ssiiy on Vancouver f.slaiid.' 18il:2. R. lirown. "On Siip- 
 })uswl ulisence of J)i-irt on tlio Pacilic iSlope," Am. Journ. Hci. and Arts, 1870. 
 (leorge {iihh.-*, " On I'liy.sical Gcogra])liy of llic Xorlli-westerii l]oinidary >»!' the 
 I'nited States," Journ. Am. (iccig Soc. \Xi\. A. K. ('. iSelwx ii. "Report ol 
 I'rogre.s", fieol. Survey (>f Canada." |s7l-7-*, p. .")li. 
 
 I Tliis and other bearings given are with reference \k> liie true meridian. 
 
SII'IMU'KIAI. (ii;oU»(iV Ob' lIHITlsll (((M'-MltlV. 
 
 !»;5 
 
 iiiid width, mikI >1io\v i:i all respects Iraees of having' lieeu subjected 
 to tiie action of ii ^'reat glacier. Where rocky hill> are reiiiarkahly 
 ahnipt. their northern slopes only have received the lull force of the 
 
 l''i'^'. 1.- /cr (iri)iirii) Jiocla 1(1 Flnhn/sdn I'iiIdI, f'iifurid. VdiiCDid'cr 
 
 ice, whicli, home uj) to some extent l»y their summits, has marked 
 the soufhern slojjcs Hli<:,htly and irrciinlaily. A com])aralively sliiyht 
 decrease in steejniess of descent has, hoM cvei'. been stillicient in 
 other cases, to eiialilo the ice-mass to follow the contour of the roek, 
 impressinii,' the southei'u slo])eswitli f;roovin<j; almost as well marked 
 a?! that of the nnrthern. This is <;enerally the case -with the rocks 
 forminii' the southern shore of the iieninsula, where the furr)ws may 
 be traced runninu:reii;ularly down beneath the sea. Here there is evi- 
 dencoof urcat lateral as well as downward pressure, vertical and nearly 
 vertical suri'aces beinii' fre(|uenlly as Avell i)olishe(l as horizontal ones. 
 Instances where rocks have actually bei'ii lluted and undercut at the 
 sides are not \nu'(nnmon (H.n'. 2). Another circu.mstance noticed in 
 unmy places, de)»endent, no doubt, on combined vertical and izreat 
 lateral pressure, and (Mnscipicnt "plasticity " of the ice, is the manner 
 
04 
 
 iii:nl!(l|: MIItCKI! liAWsON OX IllK 
 
 ill which it. lias bcoii made to tit to tho rock-siirlaces. W'iiore h 
 Huddoii drop of a finv tVet occurs to tho soutli, a dftachod toii^'uo of 
 ico has iTKJVod obliciuoly bouoath tho jj,'eiioral shoot on the lower side 
 
 Fig. 2.—i<cctlons tnmsi'crse to Direction of (j/lacintion of Hods 
 xuulcrcnt and Jhited. (Scale ') livt to I inch.) 
 
 a. Coiist -section bt'twocii A'icturia aurt Esijuim;ilt. 
 
 /'. West (jf Ogdi'ii Ptiiiit, Vietoriii. 
 
 c. ICt^qiiiiiiiilt, face of cliff, 40 i'eet above sea-level. 
 
 |'t'iK'j<e and tlic Ibllowiiig figures arc i'at'siiiiile.s of the author's draw 
 
 uigs. 
 
 of the stop, for some distance, till attain carried onwards by the nniin 
 How. In one case, at FinlaAson Point, diverivence from the chief 
 direction amonnts to forty degrees. This point is on the west side 
 of a largo bay, contiiined northward by low ground, which must 
 liavo formed the channel for i<. great mass of ice. The obli(|ne grooves 
 are so well worn as to be (juite semicircular in the outlino of their 
 transverse sections. Here is also noticeable a very general tendency 
 to sliglit divergence of furrows at the northern ends of rock-masses, 
 and convergence round points to the south. In a few cases well- 
 worn furrows showing this convergence arc seen to be crossed at a 
 small angle by comparatively light scratches, showhig a " falling- 
 off " of a few degrees from the normal course, due to the motion of 
 the last portion of Wic retreating edge of the ice-uniss, when, though 
 forward movement still continued, lateral pressure had almost ceased. 
 Selective erosion is a well marked feature; and quartz sand being 
 
sri'KKKKiAI. (ii;ul,tM;v iH' l)l(!lls|| CoMJIDIA. )!.'» 
 
 the hardest cutliii;!:-! i;it<'riiil aviiil.ilili' to the iro. portions of rook 
 coiitiiiiiiii;; ([iiiirlz in tlicir composition show jiront powers of t'lidu- 
 ranco coni]>!ir('(l with those consistiiifj; of tclspiir iind lioriddcndc only, 
 Ihou^h tiic hittcrinay boquite as coinjiact. Instances where (jnartz- 
 ose intrusions jiroteet lonjj; southward-poiutinjj; ribs or pencils of 
 diorito are not rare. 
 
 'J'hero ii])pi'ars to bo no escape from the cunelusion that a glacier 
 Hwept over the wl-.olo south-eastern peninsula of Vancouver Island 
 at some tinu' durini; the (ilaeial ])eriod ; and on consideration of the 
 pliysical features of the country it becomes ai)parcnt that the entire 
 Strait of (ieoriria between the island and the mainlaiul must have 
 been tilled with a jfreat }j;lacier, with a width, in some jdacea, uf over 
 fifty miles, and a thickness near Victoria of at leant considerably over 
 (too feet. With all this, however, tijere has been very little <j;eneral 
 wearinj'-dowu of the rock-surface ot the country; all its main 
 features, and, in many cases, even the most minute, are clearly of 
 ])reji;lacial orif^in. Tlie valleys i^enerally follow bands of limestone 
 and softer schistose and shaly beds, and run as often transverse to, 
 as parallel \.ith, the direction of glaciation ; and besides tlie j^eneial 
 forms of the smaller hills, little rocky knoUs and projecting; points 
 of rock, while "worn and rounded to the north. ])reserve rouf^h un- 
 polished southern faces. This feature is more mai'ked than 1 have 
 elsewhere observed, and Mould seem to indicate, even alio winjj; that 
 glaciers do not very rai)idly abrade solid rocks, tbat the ice did not 
 long ras]) over this portion of the country, and possibly tbat it never 
 extended much beyond this point. 
 
 Mr. (ieorge (Jibbs mentions the occurrence of glacial grooving 
 running from north-east to south-west, on Snu-Juan Island, in the 
 southern ])art of the 8trait of (Jeorgia, which would appear to show 
 that the glacier must have pushed southwards towards the low country 
 of Puget Sound, while a part may also have discharged westward 
 into or through Fuca's Strait, Glacial stiiation is also reported on 
 the mainland shore of the southern part of the Strait of (ileorgia. 
 
 b. Superficial Deposits. 
 
 The dctrital dei)osits overlying these glaciated rocks arc of a com- 
 paratively sim])le character. In the immediate neighbourhood of 
 Victoria, near the sea-level, a material which 1 believe to represent 
 moraine profonde occurs in a few localities, as a hard mass of sandy 
 clay and stones, wedged into crevic(^s in the rock, or protected by 
 its overhanging ledges. Further inhmd, in the valleys of the (lold- 
 stream, Leech, and Sooke rivers, and snuiU brooks tributary to them, 
 a very similar material forms the greater part of the drift, and rests 
 on rock-surfaces which, though generally smoothed, have only been 
 observed to show direction of movement in the single locality already 
 mentioned. Those valleys are dcep,V-shnped in cross section, gene- 
 rally surrounded by rocky hills, and often transverse to the course 
 of the ice ; and they must have formed rece])tacles which, in course 
 (){ time, were more or less completely tilk>d with bottom-moraine, 
 the remnants of which 1 believe the material abovi; mentioned to 
 
Ofl 
 
 (JKOUdr, MT'.IU 111! KAWSON oN |ll|; 
 
 rc])ros(>iit, tliuiiirli possihly in sonio ciiscs with the iulditinii of pvi'- 
 j^liiciitl riv('r-;i'!';iv('I.s nnd alliiviinii. It is ii vci'V liiiid i^rt'yisli-ycllnw 
 sandy (diiy, crowded with s\il)!uiniilav ii.nrs of varied orii^in, Imt 
 goncrally ([iiitc s'linll. 
 
 The ordinary (h'posits of th(> low soiith-oastoni pciiiiisuhi diH'cr 
 from those in ]mn<j; loss consolidated and finer, and frecpiently show 
 evident sijxns of stratitioation. Tlie material most lari^ely ro])re- 
 sented may he described as a hard, y<dlowish or palo yellowish-<^rey 
 sandy clay, often having weather-stained cracks traversin,;;; it in all 
 directions. This is frcMpiently quite massive, and contains scattered 
 stones and houldei's, wliich are iicniM'ally more or loss rounded, and 
 comparatively seldom show sij^ns of ohipiatioii, lait occasionally do 
 so very distinctly. In other ])lacof^ the deposit is more sandy and 
 j^ravclly, and the heddiii;;', which is often inclined, (piite distinct. 
 A very tiiu' blue elay, whicii rests immediately, or with tlu' inter- 
 vention of a thin layer of fjravel. on the rock-surface in sheltered 
 hollows, is only a finer form of the same deposit, it l)ein!jj imjiossihlo 
 to draw any line lietweun this and the other cli'sscs of material. 
 Tile de])osits are occasionally very irrei^nlar, as though they had been 
 stirred up by the frvounditij;' of lloatiug ice. or some such cause ; 
 while false-beddin*; and ap])earance of watcr-distui'bance arc more 
 fre(iuent on points and the localities which must have been most ex- 
 posed (tig. 'A). 
 
 Fig', 'i.- Drfx^nlts oi'Ci-lii'irig (lJachit<<l Jtorls, Vhttn-'ui, Vnvcninwr 
 
 I'" 
 
 
 
 
 "frrrf"' 
 
 I 
 
 a. Soil. 
 
 h. Yellowiftli-grey sandy clny. 
 
 r. Hard bliiisli clay, rusty cracks, 
 (1. SmiuI and gravelly clay. 
 
 The drift-deposits frccpicntly form cliffs or steep banks 30 or 40 
 t'ect in height, along the sliore. I^arge boulders are found through- 
 out, but are most abundant towards the to]) of the deposit, the clayey 
 
SL'PKRKICI.Vr, (iKDLOGV 01' llUITlsill COLUAIUIA. 0" 
 
 portion oi' wliich j^oncniUy tcTiiiiiiiitos riilhcr iihniptly above, and in 
 often snrnioiiiitod by a few leet <tf sand, gravel, iiii'l boulders much 
 coarser than the rest, and pro)iably, in part at ieast, duo to rear- 
 ranjj;enient of the lower material iilotij; a coast-line durin{jf emergeuf 
 The mounds t'orminfj; Keaeon Hill, and those heaped on the uor's 
 east side of S))rinfj; l{i(l};e behind the town of Victoria, are probably 
 thicker masses of this surface-layer, though it is ])ossible that portions 
 of these, and similar mounds elsewhere, may repiesent remnants of 
 moraines, terminal or lateral, loft at different stages in the retreat of 
 the glacier. They rescml)le much more closely, however, the deposits 
 of stranding ice, considerably modified by currents. The materials 
 in sections at Spring llidge are coarse sands and gravels, with many 
 boulders of all sizes. The largest boulders aro nearest the surface, 
 with thoir interstices filled with liner material, which also often forms 
 the supertieiallaycr of the deposit, as though, submergence still con- 
 tinuing, the supply of ice capable of transporting large blocks had 
 failed. 
 
 Extensive banks of coarse sand and gravel have accumulated on 
 the southern or lee side of ilouut l.Viuglas, before referred to, giving 
 it a crag-and-tail form. At the head of Cadbury ]*ay, about 10(3 
 feet above the sea-level, a road-side cutting shows stratified false- 
 bedded sands and gravels, the inclination of the bods, which is very 
 regular, indicating nortli and south currents like those of the tides 
 still running in the Strait of (Jeorgia, the southwnrd or ebl) current 
 being the stronger, and having most frecjuently left traces of its 
 action. The boulders near Victoria are very frecpiently of diorites 
 and granitic re -ks, derived probably from the Cascado Mountains of 
 tlie mainland t. the north and east. Large masses of the Cretaceous 
 coal-beari'ig rocks, and especially of the conglomerates, of Nanaimo 
 are also vot unfre(iuently met with. The boulders, as well as the 
 finer materials, are occasionally found forming accumulations behind 
 rocky ndgcs. The largest erratic mass observed lies near Cedar- 
 Hill c. lurch, and measures 17 foot long, I) feet 11 inches wide, and 
 7 feet ia thickness, though partially imbedded in the soil. 
 
 Mr. 15anermau mentions the occurrence >f casts of Cardinm and 
 Mija in these deposits, an observation which for a long time I was 
 unable to confii'm ; but evcntuall) several localities were discovered 
 where molluscous remains are tolerably abundant. These shells 
 were not noted in the lowest portions of the drift. They are gene- 
 rally contained in hard fawn-coloured sandy clay, almost without 
 stratification, and are frequently (piite decayed and crumbling, though 
 found Avitb the valves united in tj position of life. Granitic frag- 
 ments included in the clay are also very frequently more or less 
 decomposed, and sometimes compL .cly rotten, showing that car- 
 bonated surface-waters Tiere long acted on the mass since its eleva- 
 tion. This action may probably account for the comparative scarcity 
 of the shells, while its continuance for a period somewhat more pro- 
 longed would without doubt have resulted in their total removal. 
 The beds so affected are at a height of only a few feet above the sea ; 
 and this, couidod with their resemblance in texture to many inland 
 
 b 
 
UH UKOUGK .MKKCKIt DA\V«()N ON TIU; 
 
 diitV.-dL'po.sits, suggests uiu' means of uct;oiinting for tho apparently 
 complote ii1)sent'o of marine? remains over areas whicli on other evi- 
 dence appear undoubtedly to have been at one time submarine, but 
 vhieh from their elevation must have been much longer exposed to 
 the pereolatifm of surface-waters. 
 
 The following species have been recognized among the fossils 
 hitherto found : — 
 
 Ciircliimi isliiudiciitii. 
 
 Leda t'oss;i. 
 
 Saxiciva riiii;().s:i. 
 
 Natica elaiisa (i)rol)al)lv). 
 
 Balanus cronatiis (prob.bl.v). 
 
 In localities where tho upper sandy and gravelly layer of the drift 
 is not develojjed, the change from dee]) water to littoral conditions 
 appears to be marked by the rather sudden Introduction of carbona- 
 ceous matter, changing the clayey deposits from their usual pale 
 lints to dark brown. In some places marine shells, and especially 
 the Cdrdium above named, appear s])arsely in the highest layers of 
 the pale clays ; while in other localities, near the j)resent shore-lino, 
 the lowest layers of the shell-heaps, and burnt stones used by the 
 Indians in cooking, coincide with those of the brown earth, showing 
 apparently that tin; last movement of elevation by which the land 
 attained about its present level was rath<>r sudden, and that habi- 
 tation by a race resembling the present natives followed closely on 
 the termination of the glacial conditions. 
 
 The general ai)pearance of the dejjosits of this part of Vancouver 
 Island, resting, as they do, on plaTied and ])olished rocks perfect in 
 every detail and necessitating glacier- action for their ex])lanation, 
 and yet consisting of water-bedded and often cui'rent-driven mate- 
 rials mingled in places with sea-shells, leads to the belief that they 
 were formed along the retreating foot of a glacier which had ex- 
 tended some distance beyond the margin of the land. T>io with- 
 dravval of the ice nuiy have been caused or ac(!om])anied by subsi- 
 dence ; and some species of shells must have followed its front, 
 pretty closely in its retreat. The somewhat irregularly terraced 
 form of the deposit is probably due to action during emergence ; and 
 the general tendency of many facts is to show that a slight sinking 
 of the coast is at present in progress or has lately occurred. 
 
 Occasional artificial sections at New Westminster, at the mouth 
 of the F"aser river, on the opposite side of the 8trait of Georgia, 
 show deposits quite similar in general features to those seen near 
 Victoria ; hut no molluscous remains iiave been found. These beds 
 pass under tho modern flat and wide delta of the river, which ex- 
 tends many miles seaward. Some of the higher parts of the irre- 
 gular terraces about Victoria may be correlated in a rough way 
 with the edge of the sloping ground on which New Westmijister is 
 built ; and several islands in the southern part of the Strait show 
 cliffs of similar materials and about the same height. St. -James 
 Island may be siK-cially mentioned, its wliite cliffs, probably eighty 
 feet high, forming a prominent landmark. Vancouver Island has 
 
HUlMvKFIClAI, (ilv)I,(K,Y or miiriSIl COIX'MIUA. !>i> 
 
 probably been united at ouo timo to tbese smaller islands and the 
 mainland by a floor of deposits at about this l(5vel, thou'^h there 
 is nothing to show that it has ever formed an actual land con- 
 nexion. 
 
 r. Of.'sei'vatio)i,ii northtvard in the Strait of Geot'j/ia and at Bute Inlet. 
 
 One hundred miles northward in the Strait, deposits similar to 
 those last deserib^d form scarped banks along the shores of Savory, 
 Hernando, ^lary, the southern portion of Valdez Island and the 
 low eastern shore of Vancouver. Fragments of a terrace, estimated 
 from a distance to be from sixty to eighty feet in height, are seen on 
 the inner side of Stuart fsland in the entrance of Bute Inlet, and at 
 one other place some miles up the inlet on the west side. No higher 
 terraces or accumulations of detrital matter were seen on this part 
 of the coast ; but Mr. Richardson mentions terrace -deposits at 
 heights between 100 and 2(»(» feet in Kitemat Inlet, further north. 
 The remarkable rarity of terraces, however, and absence of drift- 
 material on the western slope of the coast-range, are among its 
 most stiiking featuri's, contrasting stroiigly with the coiulition of 
 its iidand nuirgin. 
 
 My opportunities for examining the I'cmarkable fjords by which 
 the coast of the mainland is indented have becMi limited, tlio 
 only one ascended to the head being Bute Inlet. This chasm, 
 forty miles in length, and running into the centre of the coast- 
 range, is surrounded by mountains which, in some ])laces, rise from 
 its borders in cliffs and rocky slopes to a height of from 6000 to 8000 
 feet. It must have been one of the many triliutaries of the 
 great glacier of the St'-ait of Georgia, and accordingly shows 
 evidence of powerful ice-action. The islands about its mouth are 
 roclu's woiitonnees, polished and ground wherever the original sxir- 
 facc has been preserved. In Sutil Passage, near its enti'ance, 
 groo\'ing appears to nin about S. 30° W. A precipitous mountain 
 on Yaldez Island, opposite Stuart Island, and directly blocking the 
 mouth of the inlet, though ;i013 feet high, has been smoothed to 
 its summit on the north side, while rough towards the south. 
 The mountain-side above Arran Passage, shows smooth and glisteii- 
 ing surfaces at least 2000 feet up its face ; and in general all the 
 mountains surrounding the fjord present the appearance of having 
 been heavily glaciated, with the exception of from 1000 to 2000 feet 
 of the highest peaks. The high summits are rugged and pointed, 
 I and may either never have been covered by glacier- ice, or owe their 
 
 ' different appearance to more prolonged weathering since its dis- 
 
 appearance. In some places ])arallel flutings high up the mountain- 
 sides evidence the action of the glacier : while in others it is only 
 attested by the general form of the slopes, or detected under certain 
 effects of light and shade. The mountain sides are wonderfully 
 I bare, and even when wooded have a very scanty covering of soil : 
 
 80 that after the natural forest has been destroyed by fire the 
 naked rock everywhere appears. vVt the mouth of the Kowathoo 
 river discharging into the head of Bute Inlet, striation shows u 
 
 2 
 
100 liKOKciK M KKCI'.l: DAWSoN (iN IIIK 
 
 direction of inoveiiiciil S. 22' K. ; hut in cvory case tlie motion 
 ii})pears to liiivo ])ccn directly down tlie valley, ant; to have con- 
 t'ormed to its chanp:es in course. (Jlacier-ice may still be seen 
 shininp: bluely from some of the higher valleys at the head of the 
 inlet, and further up the Howathco river there are many glaciers 
 in lateral valleys, some of Avhich descend almost to the river- 
 level. 
 
 Mr. James Richardson, who has had an opportunity of examin- 
 ing many of the inlets north of Vancouver Island, writes as follows* 
 — "Throughout the whole of the iidets and channels which wore 
 examined, wherever the surface of the rock is exposed, the ice- 
 grooving aiul scratching is very cons])icuous, from mere scratches 
 to chanuels often several feet in widtli, and from a few inches to 
 as much as two or three feet in depth. Often they can be distinctly 
 seen with the naked eye, from the surface of the wr.ter to upwards 
 of youO feet above it on the sides of the mountains. They run in 
 more or less parallel lines, and are not always horizontal, but 
 deviate slightly up or down." 
 
 ;j, IXTEIUOK 01' Humsil CoLUMIlIA. 
 
 The region lying between the Cascade or Coast Mountains on the 
 west, and the Selkirk or (Jold range and Kooky ^lountains to the 
 east, though it may be regarded in a general way as a great 
 plateau sloping gradually to the north, from its brf»ken and diver- 
 sified character offers a i)roblem with many additional elements 
 of coin]>lication. The phencnnena may be divided as l)efore, under 
 the hcfids of rock-marking or striation, and overlung detrital de- 
 posits. The striation, however, admits of subdivision into many 
 different systems; and the superficial deposits may be classed as 
 unmodified and modified drift and moraines, betwevji which lines 
 can be drawn in a manner which, though even here not always 
 absolutely definite, could not l)e attempted with the drift covering 
 the southern ])art of Vancouver Island. 
 
 a. Sfriatlon and lloclc-poUshhui. 
 
 In several eases I have observed grooving at such heights and 
 with such bearings as to preclude the possibility of its being attri- 
 buted to glaciers moving from any of the present mountain-systems, 
 and seeming to require for its ex])lanation ice-action on a very 
 much greater scale. As few localities offer, howcvei", where traces 
 of this character can be observed under qiiite unequivocal circum- 
 stances, it may be proper, in view of their interest, to treat of the 
 more important in some detail. 
 
 Tsa-whuz Mountain (lat. 53° 40'), on the direct tnul from 
 Jilackwater Bridge to Fort George, is an isolated basaltic outlier, 
 rising about 8U0 feet above the higher parts of the surrounditig 
 hilly plateau, about midway between the valleys of the I'raser and 
 Chillacco rivers, which lie east and west of it. Its ai)proximate 
 
 * Report (i| Progress Cieul, Survey of Can. 187 1-75 p- 8. 
 
aui'KKi'iciAi, «i:oi,0(iV ok muiisii ('(ti,f.\inu. KM 
 
 <!lcation nbovo the sea is ',i'240 foct ; and standing on the summit, 
 one commands a very cxtcnsivo view in all directions. Westward, 
 at a distance of about fifteen miles, across the deep Eraser valley, 
 hills surpassing this in altitude are scon. Southward no part of 
 the surface of the country is so high till beyond the valley of the 
 liluckwater river, at a distani-c of over thirty miles. Westward 
 und south-westward, with the exception of one hill of al)out e(iual 
 height, the plateau stretches for from fifteen to twenty miles ; 
 while through more than a (juadrant of arc to the north, the whole 
 country a])pears to slope gradually away from the foot ot r.sa-whiiz, 
 towi'.nis tlie low region about McLeod Lake and the Parsnip river, 
 and forms a level sea-like horizon. Xo high mountains appear in 
 any bearing. The rocks of the summit of Tsa-whuz are for the 
 most part roughened by the weather ; but in several jdacos iutlistinct 
 striation is seen ; and in one spot, within a few feet of the highest 
 point, a slightly overhanging surface of basalt was observed to bo 
 distinctly shaped and ])()lishcd ])y ice, the direction indicated being 
 a few degrees west of south. The surface of the northern ridgo 
 of the ni'^untain shows miniature rock-basins, with their longer 
 axes parallel to the same direction, and some of them holding 
 Hmall pools. The ridges which diversify tlu; surface of tlu; plateau 
 below are seen to conforjn very generally t(? north-and-soulh bear- 
 ings; and this is especially observable immediately to the south of 
 Tsa-whiiz, whero a succession of small ridges are closely i)acked 
 together, with their longer axes running S. 2'i° W. Some of these 
 hillocks probably owe their form to that of the underlying rock, 
 while others aie no doubt com])osed of gravel ; and the general form 
 of these and of Tsa-Avhitz is as though the glaciating ag(>nt had moved 
 from nortii to south. 
 
 Traces of glaciation were also noticed in several ])laces at high 
 levels on the basaltic plateau in the vicinity of the Eraser valley. 
 in ])ositions not allowing their Iteiiig referred to local action. In two 
 cases very distinct grooving was observed, in one of these localities, 
 about twenty miles nortli of the ("hilcotiii river, and several miles 
 distant from the trough of the Eraser, the direction is nearly true 
 north and south, the approximate elevation being 'A'Xyi) feet. In a 
 second instance, also on the summit of the plateau, on the nortiici'ii 
 brink of the Chilcotin valley (Lit. 52 ), at an elevation of about 
 i^()50 feet, with a direction oiS. 'Li"^ \V., or N. 2;i'^ E., being transverse 
 to the present great gorge of the Chilccjtin rivt-r, the surface of 
 the narrow basaltic plateau foi'ming the summit between the south- 
 western tributaries of the Xechacco and some of the north-western 
 branches of the Blackwater, at an elevation of '.i~'AO feet, is ice- 
 smoothed, but the direction of motion is undeterminable. 
 
 On the sunnnit of a hill which we may lall Sinter Knoll, rising 
 about 2n0 feet above tin; general level of the country, or ;{'>')(} feet 
 above the sea, noith of (Jatcho Lake, near the south-eastern sources 
 of the Nechacco river, glaciation occurs with a Itearing about S. 
 H° K. The rock of thr> hill is it romarkably brei-i-iated siliccouH 
 material - hard, but much iointcfl. 'I'h(> striatinn was oulv found 
 
102 
 
 GKuuciK mi;i(ci:k Dawson on tiik 
 
 on ono spot, ])rotectt'(l by a foreign b(»iil(lof, whicli had to bo over- 
 turned l)ot'oro it could be observed. The glaciated surface is con- 
 siderably inclined and beautifully polislied, with faint scratches 
 crossing each other at small angles. The abrupt southern face, and 
 the more gentlo northward 8lo|)e of the hill, appear to .show that the 
 ice must have moved southward. From N. J<0°E., round to N. 1H°W. ; 
 and beyond, the highest country within many miles is a ridge with 
 an elevation from loo to lioU feet greater than that of the Sinter 
 Knoll ; and beyond this only low blue hills are seen at a distance 
 estimated at from fifteen to twenty miles. 
 
 One « ' the most rcmar' able localities in which g! station referable 
 to this system was found, is a rocky hill south of the Salmon or 
 Dean river, isolated from the higher parts of Tsi-tsutl Mountain, 
 of which it forms an outlier, by a shallow valley about a mile wide. 
 The altitude of this point is 3700 feet. Westward the view is 
 across the lower broken country of the Tahyesco river to the snow- 
 clad eastern parts of the Coast range at a distance of from twelve 
 to fifteen miles. A lino drawn south-westward would cross 
 obli<iuely this wide valley for many miles before higher country 
 would be reached. To the north, the lower region and minor 
 elevations, mentioned in connexion with the last locality, are over- 
 looked. The rocky surface of this hill Inia been smoothed and 
 striated by ice moving S. 137 W., forced ap])areiiily somewhat out of 
 its usual course by the Hank of Tsi-tsutl Mountain, and passing 
 between it and the Coast range. 
 
 Near Hatty Lake, nearly 1000 feet lower 'on the last locality, 
 and sixteen miles north-east of it, in a narrow ])ass between cliffs 
 of hard Mesozoic rocks, ice has left unmistakable traces of its 
 passage south-westward, glaciating not only horizontal, but nearly 
 vertical rock-surfaces. It has eonfoimed in its direction to the 
 tributary valley of Salmon river, in which it is seen, the valley 
 being nearly parallel to the main direction of that of the Salmon 
 river, which runs towards the Coast range, and through it to the 
 sea. 
 
 Claciation clearly referable to ice spreading from the Cascade or 
 Coast Mountains, and other ranges, is mc' with in many places; and 
 generally speaking, wherever circumstances admit of their observa- 
 tion, grooving and striation jiarallel to the main couri^es of the valleys, 
 and depressions radiating from or ])assing through all the higher 
 mountains, may be found. These facts, however, possessing only a 
 local ii'terest, need not be detailed here. Other features of local 
 glaciatiou will be again referred to. 
 
 h. Superficial Deposits. 
 
 Pi'e(/laci(tl Gravels. — It is (piite probable that in many localities 
 deposits of I'reglacial date, but newer than the basalt-Hows which 
 app ar to have closed the Miocene period, may occur, esi)eeially in 
 deep and steep-sided valleys. A hasty examinati<m of the Cariboo 
 gold-mining district apiiears to show that while in some valleys, 
 especially those facing northward (c. ;/. Mosfjuito Creek), Boulder- 
 
 ' 
 
SUFEKFICIAL OKOLoCiV 01' UKITISH COl.UMUIA. lOJi 
 
 fluy Hea directly on the rock siiithce, in others th<i rich gold-bearing 
 gravels are (luite distinct from and below this deposit. In Lightning 
 Creek, the material hiling the bottom of the old stream-courso, 
 often from 50 to Ino feet l>elow the j)resent brook, is a water- wasted 
 gravel, with little clay and no cementing matter, but much com- 
 pacted by pressure. This is richly auriferous, and has been 
 followed by extensive mining-o])erations. Above it, in the valley- 
 bottom and clothing the sides of the surrcnuiding hills, is Jjoulder- 
 clay, which yields little gold ; and on this again are recent moditied 
 deposits of gravel, over which the stream of to-day linds its course. 
 These last are generally also more or less auriferous, forming 
 " shallow diggings." 
 
 Uamodijied Drift. — The whole interior of British Columbia, up to 
 elevations of over r)(MX) feet, may be said to be more or less thickly 
 mantleu with unmodified or scarcely stratified deposits, which 1 
 shall refer to as Bimlder-clay. Over considerable areas this material 
 is concealed beneath later accumulations, which form terraces and 
 low-level flats, in relation to i)rescut and furiner lake- and river- 
 valleys. There is a renuirkable uniformity about these Houlder-clays 
 in every locality in which I have examined them. In many places 
 they form low rolling and broken hills, between the river-troughs, 
 above the level of the higher terraces. ]n this case they a])pcar 
 sometimes to be spread in a comparatively thin liiyer over a rocky 
 substratum ; while in others they are of gri'at dei)th, and, by the 
 irregularity of their arrangement, themselvtis prodtue many of the 
 minor features of the surface. They frequently show a ti'ndeney to 
 form more or less well-defined high-level plateaux, and are spread 
 almost universally over the elevated basaltic regiim of the interior, 
 in most places so uniibrmly, notwithstanding minor irregularities, 
 as to allow the underlying rock to be veiy seldom seen. 'J'he 
 Boulder-clay is (piitc typiciilly developed on the basaltic plateau 
 crossed by the main waggon-road between Clinton and Bridge Creek. 
 This plain, isolated by deep river-valleys, is traversed by the road 
 for a distance of about thirty-five miles, and has an elevation of 
 from J3i}(»0 to 42<K) feet. The Boulder- day may be described as 
 consisting of a paste of hard clay, always more or less arenaceous, 
 and generally with a very considerable pr(j])ortion of fine sandy 
 material, through which stones of all sizes are irregularly scatteitd. 
 Its usual colour varies from light-brown to pah^ greyish-' rown and 
 fawn colour, but in freshly ex])osed sections is sometimes biuish-gi'ey. 
 It very often, over extensive regions, forms the soil in which the trees 
 are rooted, without the intervention of any modified material, and 
 is frequently so arranged as to surround larger or smaller depressions 
 which hold lakes and swamps. The greater part of the stones and 
 boulders contained in ilie clay or scattered over its surface, are 
 almost invariably rounded and waterworn, and sometimes very 
 perfectly so; yet a projxntion showing distinct glacial striation, and 
 some glaciated fragments worn flat on one or nu)re sides, may always 
 be IVamd. The (juantity oi distinctly glaciated material varies 
 much with locality, and, no doubt, d»>])ends in part tn the nature of 
 
104 
 
 uKoitiiK mi;k«'1-;u dawsox on tih", 
 
 the rocks themselves. The pebbles and boulders very genera) ly 
 show a clear relation to tlie rocks of the country ovct which they lie, 
 being composed in great part of these rocks, but mingled always 
 with some proportitm of foreign material. The surh <•(> of the l)asaltic 
 plateau above described shows, for instance, not only basalt of varied 
 texture in great nlmndance, but a considerable ([uaiitity of fragments 
 from the Lower Cache Creek SeriesoftheCJeological-Survey Reports ; 
 some, pretty certainly derived from the Cascade Crystalline Series ; 
 and others, of \\ hich it is not always possible to trace the source, 
 but which certainly do not occur on the plateau. \\ here those 
 varieties of basalt which easily break on weathering into polygonal 
 fragments occur, the overlying Jionlder-clay is filled with tln.'m, so 
 that in many places, after prolonged subaerial weathering, the s\ir- 
 fae(! appears to be absolutely composed of blocks of stone. 
 
 'i'lie general direction of movement of the travelled constituents 
 of the lioulder-elay appeals to have been southward, though the 
 diversity of the rock fornuitions, and our present ignorance; of the 
 details of their distribution, preclude, to a great extent, the use of 
 erratics in this in(iuiry. 
 
 Houlder-day has been noted in the Cariboo country up to over 
 4r)()(> feet, though the stony materials appear near this elevatioti to 
 be becoming more angular. The state of the weather during my 
 visit to the region prevented the examination of higher levels. Be- 
 tween Quesnel and JUackwater I'ridge it forms nn undulating 
 plateau, of which many portions surpass JiuOu feet, levelling up the 
 irregularly hilly surface of the hard old rocks b>^loAv. Jietween 
 Elackwater Bridge and Fort Ceorge it appears at 1 11 heights up to 
 over 34t»(» feet. Waterworn trans])orted pebbles aie found on the 
 sumn)it of Tsa-Avhuz nu)untain, above mentioned, -while on its nor- 
 thern slope a great collection of larger erratics ajipears. North of 
 the BlackM-atcr, in longitude 124° 3U', several broad ridges with ele- 
 vations of from 40(l() to 4;i(i0 feet are entirely covered with drift- 
 material, with the addition of great nimibers of boidders larger than 
 are elsewhere seen. Two high hills passed over by the trail from 
 Eraser to Stuart ].ake, with elevations of 37!>2 and 45)10 feet, aro 
 covered to the summit with Boulder-day of the usual appearance, 
 but holding more well-glaciated stones than usual, some of whidi 
 have evidently been derived from the north. In the Chilcotin country 
 similar deposits overlie the basaltic plateau at elevations above 3(100 
 feet. These instances may servo to illustrate the distribution of the 
 Boulder-clay without cnteriiig further into details or attempting to 
 describe the numerous localities in which it has been examined. 
 
 In one place only have I found what I believe to be the u])ward 
 limit of these dejxjsits. This is on the northern slope of the Il-ga- 
 chuz Mountain, at an elevation of 5270 feet, whei'c it coincides with 
 the highest known shore-line. 
 
 In the mixed character of the stones of the Boiiider-clay and their 
 very generally rounded and waterworn aspect, though cm^losed in 
 nuiterial with little or no stratification, the action of water-borne 
 ice, whether iceberg, line, or shore-ice, seems to be indicated. 
 
 I 
 
SUPEKKICIAL fiKOLOOY OK URITlsri COIXMUI.V. 
 
 1(!') 
 
 Modijhtl Drift. — As already montionod, extonsivo areas uf tho 
 bouldiT-clays are entirely coiiceuled l)y uewor overlyins; deposits. 
 It may be almost stated as a vul<^ that, in rcf^iojis )yiii{? lower than 
 ;UH)0 feet, tho supcrtiiial materials are entirely of this more j-ecent 
 date. These are cVteii cleiirly traiiealile to ancient lakes, of which 
 th<^v yet. d"fiiie the oiitlincs, but in other cases are due mereh to the 
 successive rearraiigcmeiit of material by rivers slowly cutting down 
 their \ alleys. The extent of surface below the above-mentioned 
 limit in the southern part of Ikitish Columbia is comparatively 
 small ; and the more or less isolated later deposits present varying 
 local characters. To the north, however, the general lower elevation 
 of the country has allowed the formation of beds more wide-spread 
 and important. I have examined the southern ])ortion only of this 
 lower area, tho northern extension of which passes in a wide belt 
 along the Parsnip and through the Peace river-depressions in the 
 Rocky ^lountains to the great Mackenzie river-basin*. 
 
 The l)est sections of the deposits of this northern area arc found 
 in the Lower Nechacco basin, between lat. Oii°;3<»' and 54° !(»', and 
 long. 1 2;i'' and 1 1'4° 4( >'. They reach a height of about 24U0 feet at the 
 edges of their basin, and where seen lowest (near Eort (ieorgiO have 
 tin elevation of liiOd feet. Their known area is about KM III s(juare 
 miles ; biit they may extend far northward. They seem to represent 
 an interesting epoch of the Glacial period, and are compose*! of nearly 
 white, greyish or pale chocolate-grey arenaceous clay, divided by 
 distinct stratiticatioji-phuies into layers an inch or two in thickness, 
 and very uniform in this res])cct. When dry the material is hard, 
 but not sufficiently homogeneous to break regardless of bedding- 
 planes. Under the microscope it is seen to be made up of very tine 
 angular quartzose particles, mingled with a little formless argillaceous 
 material. Jt is usually calcareous, and is tilled in many sections 
 with calcareous nodules, generally lenticular, but often contiaent, 
 forming grotes(iue aggregations. These arc esix^cially abundant on 
 the shore of Stuart Lake near Fort St. James, and in some of the 
 Nechacco-River sections. 1 have called these deposits the White 
 Silts. 
 
 The beds arc sometimes seen to be disturbed, and even more or less 
 contorted — an appearance which has, L think, often been produced 
 by " slides " in the banks of the river of comparatively recent date. 
 Contortion, however, sometimes seems to have been caused by the 
 contcmi)oraneous action of Hoating ice, the in'csence of which is 
 proved l>y the occasional occurrence of large subangular boulders, 
 which generally lie in groujis, and are often as much as two feet in 
 diameter. The portions of the formation holding many boulders 
 seldom show distinct bedding, though comi)osed of material similar 
 to the rest, and not mixed with much gravel or beds of coaise de- 
 tritus intermediate in character between the fine matrix and the 
 erratics. In some cases the White Sills are fonnd to have been de- 
 posited in gently inclined beds on preexisting sloping surfaces. They 
 
 Selwvn, Rpport ol ProprciB Gcol. Surv. "f Cnnadfi, 187r)-76. 
 
100 
 
 GliOROE MKHCKR PAWSO.V ON THE 
 
 are occasionally soon on the Nochacco below Fiuser Lake to rest on 
 falso-bcdded sauds and clayey f^nivels (whicli may liere probably re- 
 present a part of the Houbler-clay), and were observed to overlie in 
 one section a hard yellowish .sandy clay with lew stones. The V/hite 
 Silts arc also found to rest directly on denuded Tertii ry beds and 
 other oIult rocks, Jn one section on the Lowe/ Xechaoco. their 
 relation to well-marked Boulder-clay is very di.^tinctly seen (Hg. 4). 
 
 Fiii. 4. — Sxtion on Lower Nechxcco River. 
 
 ■"jste^ 
 
 'M 
 
 'm'\'^^^^:^l^ 
 
 .B 
 
 X t^- 
 
 ".^^ :^= 
 
 • -_ e. 
 
 « ♦ » _, 
 
 >lu'" , ' o ";•"' •11,1, Ml ■', o .',■ 
 
 rt.i'i 
 
 ^''0 
 
 o'\o „ 
 
 
 f. * 
 
 |g. o''i^;:^ ''k;''Hi;'^''& ■^m 
 
 a. Soil. f). White Silt. 
 
 c. Hard, grey, sandy clay, with rounded and siibangular stones, some 
 
 glaciated. 
 
 d. Bluish aaiidy clay, with boulders and pebbles generally somewhat water- 
 
 rounded, but nearly all glaciated more or less distinctly. 
 
 The lowest bed exposed here is a hard bluish arenacoous clay, with 
 email boulders, and pebbles of all vv'es, mostly more or less water- 
 worn, but nearly all showing traces oi glaciation. There is little or 
 no appearance of stratification. This is separated by a distinct 
 horizontal line .'.om the next layer, which is paler in colour, harder, 
 and somewhat more arenaceous, and (iharged with smaller pebbles 
 less evidently glaciated. The stratification is obscure. A second 
 sharp horizontal line separates this bed from the overlying White 
 Silts — hard pale arenaceous clays of the usual character, which be- 
 come disintregated above to form the soil. 
 
 The thickness of the White Silts must be over 100 feet in some 
 sections and might very probably, if fully exposed, be found in 
 many parts to exceed 2<>0 feet. The deposit shows a close general 
 resemblance to the thick argillo- arenaceous or locss-liko material of 
 the plains of the lied lliver in Manitoba ; and very similar conditions 
 may probably have led to the formation of these beds in the two 
 localities. In "ooth Afiniitoba and the Nechacco basin the material 
 is generally calcareous, and in both places it forms a most fertile 
 soil. In the Nechacco country it seems piobable that the silts were 
 laid down in the bottom of a great lake, at a time when all the pre- 
 
 « 
 
Sl'I'KI'.FICIAL UEOtOGY OF BRITISH COl.UMUIA. 
 
 eent "mar^r basins wt e united, which may pus^ihly have allowed 
 the access of tlio sea to some extent. They liavo tlio apjM-arani'u v( 
 bcinf^ the deposit from water c]iar},'ed with tine-. 1; cicr-mud, or tlour 
 of rock ; while tho prosenco of f^laciatcd boulders pro cs either that 
 Hoinc of tho f^lacicrs yet extended far enoufijh from their sources to 
 reach tho waters of the like, or that heavy coast-ice existed. 
 
 In ap]troachin<? the mouth of tho Xcchacco, <>ravelly deposits of 
 ,n;reat thickness arc found, forming? exposures in some banks over 
 2(H> feet in licij^ht. The gravels alternate irre;j;ularly with sands ; 
 and tlio whole is (juito freipiently false-bedded on such a scalo as to 
 imply very strong current-action. Tho material of the gravels hero 
 too ceases to bear so closo a relation to the country rock, becoming 
 mixed with a considerable proportion of (juartzitc shingle, the origin 
 of which will be referred to heroaftcr. These sandv and gravelly beds 
 apjieai in the main to intervene between tho Houldcr-day and tho 
 VVliite Siitii, but are most closely related to the latter. They may indi- 
 cate the course of stronger currents coming from the north with much 
 shingle-laden coast-ice, the upper part of tiie Nechacco basin being 
 at this time a great sheltered bay in whii'li the more typically deve- 
 loped White Silts wero being formed. With the cxce]ttion of tho 
 Fraser valley, which may have been tilled with the earlier drift c.c- 
 posits, the lowest gap in the southern rim of the White-Silt busin is 
 found near the southern sources of the Chilyco, at an elevation of 
 2('>(jU feet ; and here a wide belt of country shows coarse and fine 
 su])erficial sandy deposits, with little gravel, forming low mounds 
 and ridges, which evidently owe their forms to mi»dcrately powerful 
 current-action, and may show tho southern continuation of tho 
 current above indicated. 
 
 Shore-lines, Terraces and Benches. — The interior of British 
 Columbia shows water-marks in different stages of ])reservation, from 
 a height of 5270 feet down to the i)rescnt sea-level. Some xacts 
 bearing on this division of tho subject have already been given in 
 connexion with other matters ; it will bo necessary here to give 
 only a brief review of the more important features, mentioning u 
 little more fully a few of the most remarkable. It is necessary, 
 though sometimes difficult, to distinguish as far as possible between 
 shore-lines of the sea or former great lakes, and terraces which are 
 duo to the gradual lowering by erosion of river-beds in tlieir valleys, 
 which bear a (piite different sigiiificanco. 
 
 Tho highest observed beach is that of which the elevation (5270 
 feet*) has already been given as probably the upward limit of tho 
 Boulder-clay •.. it was found on the northern slope of 11-ga-chuz 
 Mountain. The undulating and more or less broken plateau stretch- 
 ing eastward from this mountain, wath a general elevation of about 
 4500 feet, appears to owe the form of its surface in great part to the 
 arrangement of drift ui)on it, and shows much foreign material. On 
 
 • This lit'ijilit may be npardi'd as fixed with some aeciiraey, the figures 
 beiiifi tlie inean i)htaincd iVnin t^^o baroTiieti'if observations made on the ferraee 
 and simultaneously nt a neighbouring station, of which tfie elevation had been 
 iiiPlrintientallv fixed. 
 
108 OKonoi: MioRrtu dawson on thk 
 
 July 22nd wo camped on tho north-oiustnlopcof the mountain, in the 
 valley of a little »tivarii svhicli, after runiiin}; between high sloping 
 hanks for about a quarter of a mil«\ opens widely north-eastward, 
 in which direction the whole .surface at the .same time slopes away. 
 Here distinct though somewhat worn terrace-inark.s occur in tho 
 sides of the little valley ; and in travelling a .short distanci; westward 
 along the mountain-side, these may be observed to spri'ad quite be- 
 yond tho valley of the brook, and fonn an extensive, nearly level or 
 only gently undulating, tiat on its northern slope. The material of 
 the Hat is evidently rolled and water-rounded, like beach -shingle, and, 
 though in great part derived from the volcanic rocks or tho moun- 
 tain itself, has a considerable percentage' of travelled stones, some of 
 which are as much as a foot in diameter. At higher levels on the 
 mountain-side this rounded material does not appear, and, as far as 
 observed, no fragments not referable to tho rocks of tho mountain 
 occur. Northward, with th»^ po.ssible exception of oiu) peak forty 
 miles off, no land equal in height to this terrace is in sight. The 
 average elevation of the country is probably 2000 feet less. I have 
 not had tho opportunity of examining other parts of this moi.ntain 
 or the ranges cast and west of it with care ; l)ut from a distance the 
 Houth-ea.st side of this one shows a well-marked line, sci)arating tho 
 higher peaks from the low sloping base. This was noted and sketched 
 as a marked feature before the existence of the shore-line above dc- 
 Hcribed was known (fig. ')), In height the two must nearly if not 
 exactly agree ; and it is more than probable that the different appear- 
 ance of tho lower and njiper parts of the mountain is largely owing 
 to the distribution of the drift upon it. 
 
 The general evidence of the submergence of the interior during the 
 formation of the iioulder-day to an extent of from 4000 to 5000 feet, 
 depending on tho composition aud appearance of that deposit, has 
 already been given. The tendency of the lionlder-day toform elevated 
 undnlating plateaux, even when unsupported by the basaltic plateau 
 and resting on an uneven surface, has also been referred to. When 
 terraces occur in seres upwards from river- or lake-valleys to the 
 summit of the plateau, the highest generally consist not of water- 
 washed sands and gravels, but of lioulder-clay, little or not at all 
 modified — a circumstance seeming to prove the formation of the 
 Iioulder-day to have been still in progress while the Avater passed 
 through the first stages of its retreat. In ascending from the lilack- 
 water, these Bouldcr-clay terraces ai>pear at about 3150 feet. 
 
 The north-eastern or upper end of Tatlayoco Lake touches the 
 plateau-country, while its south-western stretches into the Coast 
 Mountains, through which its waters eventually pass to the sea. Its 
 elevation is 2747 feet ; and terraces quite well marked api)ear on its 
 south-eastern side to a height estimated at 1500 feet above its waters, 
 or 4250 feet above the sea. Fraser and Francois liakes arc bor- 
 dered by terraces, the best-marked being estimated at 100 and 200 
 feet above the lakes respectively, which, allowing for their diffe- 
 rence in height, no doubt represent the same water-line, the a]»prox- 
 imale elevation of which above the son is 2M5o feet. The hill's 
 

 SlM'KKIflCIAL (IKor.'iOY (H' IIKITIHII COM'MIIU. 
 
 109 
 
 en 
 
 I- 
 
 ^ 
 
 M 
 
 
 t;. ,\^ \jO ^ 
 
 
 :..4- 
 
1 lU UKOUiil; MKUl'Kll KOVKiiN i)N IIIK 
 
 between KraHcriuid Stiuirt l/ikos, iilrcaily inciitiouod, show ii siioccs- 
 sioii of wiitor-miirks in .s(»in(' i>l;ircs to an ('lt'vatii)ri (tf ''t least MSiMI 
 feet. They .stand in a low I'ountry as spurs or outliers in the liasin 
 of the White Silts. Mr. Smith, of the Canadian I'aoitic- Rail way 
 Survey, ;iives the j^eneral hei;;ht of the hiu:hest well-niarke(l Ix'uehos 
 of the Kramer and its trilnitaries, which lie has observed in dilferont 
 localities more than 1'>I> mile:* apart, at from 2in() to 2.')(»0 feet. 
 To this H.aj^e the Fra.sci' and Franeoi.s Lake-(eri'aee.s no doubt belouj;. 
 
 Sonii^ beacliLS, remarkable from the natu'e of the nuiterial eom- 
 posinjj; them, r.ccur on the direct trail to Ft.'ft (Jeorj^e, betw<H'n Tsa- 
 whuz Mountain and that place. The aspect of the country from 
 Tsa-whu/, and its j;eneral n )rthern Hlo])e, have already been described. 
 In f^Tiidually descending the slojie, towards the basin of the White 
 Silts, Jioulder-elay, previously forminj;; the siirr'ace, nearly (lisap])ears, 
 and is replaeed or covered by shinii;ly deposits composed of well- 
 rounded stones, which are t'or the nu.st part very compact (piartzites 
 of various ])ale tints, almost precisely rosemblinp; the (piartzite 
 drift formerly described as oc.-urrinjr on the hijj;her levels of th<> 
 plains ea:st of the Jfocky Mountains *, atid would appear probably 
 to have been derived from tlu* .smne series of rocks. The shingle 
 beaches or mounds have no very uniform general direction, but form 
 low gently-swelling undulations which bear forests of scrub-pine, 
 separated by swampy hollows densely tilled with bhu'k spruce. Tho 
 shingle-beds may, I think, bo pretty safely correlated with the thick 
 grav(>lly deposits seen at a lower level near Fort (Jeorge, and, if so, 
 l)robably represent the margin of the White-Silt sea at one stage. 
 Their approximate average elevation may bo stated as 210(1 feet. 
 An "uteresting (juestion occurs with regard to the origin of their 
 mai..i'ials. Xo rocks similar in cluiracter to their quartzites have 
 been found in this part ;)t' JJritish Columbia. It is ])robablo that 
 they have been far transported across the northern low country, 
 or derived from exposures on the northern spurs of tho Cariboo 
 range. 
 
 The materials of the lower terraces of the river-valleys, though 
 sometimes interesting, are more local in their character, and not 
 signitieant in tracing the origin of the drift-deposits as a whole. Tho 
 terraces in the bottoms of the valleys, and nearest the bed of the 
 stream, usually show the coarsest gravels. The rivers being in 
 almost all cases rapid streams, subject to great Hoods in the early 
 summer, constant transport of material is still going on in their 
 Ciiannels ; and in Cvjnsc(pienco the river-gravels do not bear nearly 
 so closo a relation to the local formations as those higher up the slopes 
 of the valleys and on the plateau. In passing in a canoe down those 
 parts of the Frascr which are considered navigable, one is constantly 
 struck by the peculiar sharp hissing noise caused by the grinding 
 and onward movement of the gravel in the river-bottom. This may 
 be heard in all the " riffles," or little rapids, even at low water, and 
 evidences the extensive transport and consequent corrosion in pro- 
 
 * Quart. Jouni. Grol. Soc. ^'ov. 187r>, vol. xxxi. p. (>10, and ' Geology and 
 Kesuurcea of the t'.tth Parallel,' p. '2'M. 
 
Sfl'KllFIClAL ()KOt.()(JY OK IiniriSlt ('oI.UMIIIA. I 11 
 
 f,'ri'SH. As a result of thin action in tho Fnisor, the (pi irtzito drlf* 
 (Itvi !,.;»(.'(1 in tlic vicinity of Kort (Jcorjj;*- liiis Ixn-n (Ira^Lrcd down 
 strtfun ill ;,'roiit ([uantity, imd cmi still, 1 Ixdiovc, be n-cognizod us 
 an important constitncnt of tho gravel banks to near tido-watcr. 
 
 The dis[)lay of t(!rraoos or" Im'McIu's " o?i the Frascr andTlionipson 
 rivors and Homo of thi'ir tributary streams is prol»al)ly as imposiii<» 
 OH can be seen ttnywhore. hi soino cases lb«'y may show nierelj 
 stages in llie descent of tbe rivers to their jjrescnt levels through the 
 wide-si)rea(l deposits of tlie (ilacial period; but as many of them, 
 and especially those of he higher levels, are seen to leave the im- 
 mediate valley.', of the i.f rs, attach themselves to the bases of the 
 hills, at'd fringe! at siirnla elevations all trie ramifications of the 
 streams into the plateau, it would seem that some at least must owe 
 their origin to the general inundation of the country, and its subae- 
 (picnt gradual drainage. Such an overflow may have been the result 
 of a, general de])ression of the land, or of the stoppage of the southern 
 outlets, more especially of the Fraser valley, and, for the higlior 
 terraces, those also of the streams runtiing southward across the 
 4!ith parallel. I'artial movements of upheaval and de2)ression 
 might also account for the damming-back of water in valleys pre- 
 viously formed ; l)ul of this no ovidencc has yet been found *. 
 
 In travelling up the Fraser valley through the Coast-range, ono 
 has the widest opening anywhere existing through these mountains 
 at one's back ; yet, step by step, the terraces can be followed from 
 near the sea-level to tht highest water-marks observed. At Yale, 
 on the outer border of the range, lOO feet above the sea, are ter- 
 races with mirrow treads, composed ehielly of angular debris, but 
 forming well-marked horizontal lines on the mountain-slopes. One 
 of these, barometrically measured by my friend Mr. A. Bowman, 
 was found to have an elevation of !S00 feet above Yale. The highest 
 perfectly distinct line was estimated to reach 1500 feet. It may be 
 open to (juestion whether these bonchcs may not be remnantsof lateral 
 moraines of an old gr(>at glacier which has tilled the valley. They 
 look, however, like shore-lines, caused by the accumulation and hor ;- 
 zontal arrangement below the water-line of debris from the moun- 
 tain-slopes. 
 
 Following the gorge or caiion of the river through the Coast-range, 
 besides lower terraces from lOO to 200 feet above the stream, every- 
 where visible, occasional fragments of benches bearing a close resem- 
 blance to those at Yale, may be seen perched far uj) on the mountain- 
 sides. About a mile above the Stoyoma lliver of the Admiralty Map 
 (25 miles above Yale) some of these were estimated to be as much 
 as 2000 feet above the water, or about 2450 feet above the sea. At 
 Eoston Ear terraces estimated at about the same height were seen. 
 Near Lytton the Thompson river joins the Fraser, the valleys be- 
 come wider and the terraces well-defined and bioad. One, baro- 
 
 » Mr. Selwyn discusses some of these points in the Report of Progress Qeol. 
 Siirv. of Canada, 1871-72 (p. 55). Sir Matthew Begbie has also pujlished 
 some account of the terraces of tbe Fraser; but I have not been able to refer to 
 his paper. 
 
 i 
 
112 OKOUGR MK.RCKR D.VWSON ON THE 
 
 metrically measured, is KiSi) t'eetiibovo the scii ; others stand at esti- 
 mated heiglits of from 1 T-'^U to 1880 feet. Further up the Thompson 
 a terrace, again barometrically mcjisured, was found at 1 (IDO feet, and 
 u second, well defined, estimjited at IIJOO feet. These are no doubt 
 the same as the two last mentioned. On the Honaparto river (tri- 
 butary to the Thompson), four miles north of Cache Creek, a terrace 
 estimated at 2820 feet occurs, and furtlier on, at Maiden Creek, one 
 l)arornetrically measured at 2()80 feet. On luscending the plateau 
 beyond Clinton (already mentioned) ill-defined " Eoulder-clay ter- 
 races" are seen, in some places, above !300ii feet*. On entering the 
 Thomj)son Valley the material of tlie terraces becomes much finer 
 and more argillaceous than on the lower Fraser. In sonui places 
 several hundred feet of nearly horizontal clay beds are exposed in 
 transverse ravines, and seem to form the material of the terraces 
 running along the sides of the valley. The lower terraces, wliicli 
 are always the best-preserved, are seen in many places to S]>read 
 quite widely, and their deposits (shown in sections both parallel and 
 transverse to the valley) to lie in beds nearly horizontal, or with a 
 slight sag towards the centre. Individual gravel beds civn some- 
 times 1)0 traced in the banks for a mile or more. 
 
 Carefully noting the aspec> of the terraces in ascending the Fraser 
 and Thom})Son rivers, which flow in the main-drainage valley of the 
 great interior of British Columbia, tracing them from ])oint to point 
 with scarcely any break, and ui)ward to the higher streams and most 
 secluded nooks among the mountains, where denudation has been 
 least eifective, the conclusion is forced on the mind, that, while many 
 of the higher are accmnulations along the 8ti>re of a great sheet of 
 \\ater, most of the lower have been carved out of deposits which at 
 one time filled the valleys from rim to rim, and more or less com- 
 pletely levelled np the broken surface of the country, by the gradu- 
 ally receding waters of a lake or of the sci, and eventually by the 
 rivers themselves deepening their channels to their old Preglacial 
 levels. 
 
 Moraines. — In some cases it is not easy to distinguish between 
 certain fragments (jf high-level terraces and old, lateral moraines. 
 Much doubt may also obtain with regard to the ori!;in of moraine- 
 like forms when m the last stages of degradation 'a-om subse(pu?nt 
 water-action and subaerial decay. A further difficulty is fre(]uently 
 found in British Columbia in ridges simulating moraines, formed 
 where successive slides have taken place in great beds of drift- 
 deposits surrounding rivers and lakes. Disregarding, hovrever, all 
 cases in which there can be the least doubt, there still remains 
 abundant evidence of the great extension of glaciers from the pre- 
 sent mountain-centres, and their sporadic appearance in many parts 
 of the highlands and hills of the plateau. These appear to be the 
 
 # The tei-nicps above eminierntecl occur in the vicinity of the main waggon- 
 road. Tlie nieasiirenienta lay no claim to accuracy, being in many cases merely 
 eye estimates aided by the known elevations of certjiin localities and the baro- 
 meter. They may serve, liowovor, to show llio succession met with in travel- 
 ling inland. 
 
SUPIIHFICI AI, (.V.i>H)0\ OF IIIUTISII (.'OI.UMDI A . 11 ij 
 
 last iiidicalions of glacial action on a largo scale, and to have l)cen 
 t'ollowod by the rotrcut of the ice to its present limits. 
 
 There are, however, a few cases where some traces seem to remain 
 of older moraine-like accumulation, which, whether due to glaciers 
 proper or to pack-ice, are probably of the date of the north-to-son th 
 ice-mcveiiieiit which the rock-striation proves to have occurred. The 
 most marked instance of this 1 have seen is in the broad depression 
 between tlie 11-ga-chuz and Tsi-tsutl volcanic ranges, through which 
 the iii)pc'r part of the Salmon river Hows northward. These ranges, 
 as before mentioned, lie transverse to the general direction of the 
 plateau-country of the interior. The depression between them is 
 about lifteen miles in width, and is thickly heaped with material 
 not nnlike the general IJoulder-clay covering, but arranged, with 
 greater or less regularity, in mounds and ridges with general east- 
 and-west bearings, separated from each other by intervening swamps, 
 in the lowest part of the depression the Salmon river cuts through 
 a steep gravelly ridge which, though tortuous, has a general course 
 about N. 70° E., and runs for a mile and a half or more. This 
 may be of the nature of au esker ; but, from its association with the 
 morainic ridges above, in which the size of the- boulders quite pre- 
 cludes this explanation, this does not seem probable. If water-borne 
 ice, Avhcther iceberg or pack-ice, be supposed sufRcient to account 
 for the north-and-south glaciation of rocks, these and other moraine- 
 like accummulations may represent localities Avhere heavy ic« 
 stranded and forced up l)ottom-n-iaterial ; while in places more ex- 
 posed to open Avater and loss to great accumulations of ico, shingle- 
 deposits, like those described on Fort-Oeorge trail, may have been 
 in process of formation. 
 
 Of the later outfloAv of ice from the prcsunt mountain-systems, I 
 have had most opportunity of stuuying the traces of that whicn 
 moved eastward from the Coast or Cascade range. It is evident- 
 hoAvever, that a similar movement must have occurred from the 
 Selkirk and Gold ranges and lioeky Mountains, though perliaps 
 not to 80 great an extent, as the precipitation of moisture in these 
 regions is much less. 
 
 The glaciers moving eastward from the Coast range appear in 
 all cases to have folloAved the pret-ent river-valley^' pretty closely : 
 i/ud though they must have overlai)])ed the higher country in some 
 pljces, it is in the immediate vicinity of the great transverse de- 
 pressions noAV occupied by the rivers that their traces are most 
 evident. Naming these valleys in succession from south to north, 
 but Avithout entering into particulars, the main facts m.iy be stated 
 as follows : — 
 
 JS'icola Valleij. — The river flows westward ; but the driJt-material, 
 consisting of boulders and gravel, is largely, in some cases chiefly, 
 composed of granitic and syenitic rocks derived from the coast- 
 mountains, Avhich have been carried eastward, and now oA'erlie 
 Nolcanic rocks (piite different lithologically. This is the case to 
 the lower end of Nicola Lake, Avlure the drift assumes a more local 
 character. No distinct moraines were observed. 
 
1 14 GKOHGK >IKIU I)!! 1)A\VH(,X 0\ THE 
 
 Thompson Valhy. — The rivor Howd sontli-westward to its junction 
 with tho Fraacr at Lytton. Fragments of tho rocks oi' the Cascade 
 mountain-series, in the form of large and small boulders, produce 
 a rather irregiilar but evident moraine overlying rocks of a diff'erout 
 character, twenty-four miles above Lytton. 
 
 Tho glacier, in both tho above case" must have crossed the deep 
 valley of tho Fraser ; but the localities to which it has here reached 
 can scarcely be said to be beyond the eastern flanking mountains of 
 the Coast range. 
 
 Chileotia Valiey (lat. '}2°). — Moraines can bo traced here with 
 cert'inty as far as the lower end of Tatla Lake, and with great 
 probability to the outflow of Puntzee Lake. The former locality is 
 situated twonty-tive miles from the eastern base of the Coast range, 
 and tifty miles from its central region; the latter forty miles from 
 the eastern base. There is considerable reason to believe that tlie 
 moraines of these places have been formed by a glacier pushing out 
 into water, and sonjewhat modified by water-action, either con- 
 temporaneously or immediately after their formation. A congeries 
 of small ponds, lakes, and swam])s, called tho Buckhorn Lakes, 
 owes its existence to the steep-sided holloAvs, cup-shaped, trench- 
 like, or crescentic, enclosed between moraine ridges, ifany of these 
 ])onds have no visible outlets. A sheet of water six miles in length, 
 called Eoglo Lake, is dammed at its eastern end by moraino- 
 material, in which very large angular blocks, evidently derived 
 from low rocky hills at the sides of the valley, form a prominent 
 ingredient. The watershed between the Ilomathco river, flowing 
 directly through the Coast range to the sea, and branches of Mie 
 Chilcotin, flowing eastward to the Fraser, lies just within the 
 eastern foot-hills of the Coast range, is low, and apparently 
 composed altogether of drift-material, more or less evidently 
 morainic. It is probable that before the Glacial period the waters 
 of a great extent of country now draining towards the Fraser, flowed 
 by the gorge of the Homathco through the Coast range. Lakes 
 and pools without outlet, irregular morainic hummocks and ridges, 
 projecting to a greater or less height through flat or gently undu- 
 lating deposits formed from their waste, characterize eijually the 
 sources of the east and west branches of tho Homathco. A general 
 movement eastward from the valleys of tho mountains can be proved 
 from the composition of the drift. 
 
 Blackivater and Sahnon-JHver Vallci/n (approximate latitude 55^). 
 — The tributaries of these rivers interlock about the 125th meridian, 
 tho former flowing eastward to the Fraser, the latter westward, 
 chrough the Coast range. Moraines which appear, without doubt, 
 to belong to tho Coast-Moantain gluciers, occur beyond the low 
 watershed on the tributaries of the lilackwator, at a distance of 
 forty-five miles from the eastern b; so and sixty-five from the central 
 peaks of the range. These are seen in the neighbourhood of Tsi- 
 toe, Klootch-oot-a, and otiier smsill lakes of the same group. Six- 
 teen miles further westward, at I'hl-ghak Lake, glaciation with a 
 course of N. 8U° E.. evidently referable to this period, occurs. In 
 
SUPKRFU'IAI, GKOLOGV OK ItlUTlSU roMJMltlA. 1 I ") 
 
 the valley of the Salmon rivor, and in the nearly parallel one occui)io(l 
 by Tanyabunkut Lake (before referred to), moraines, in some cases 
 nearly parallel to the sides of tlie valleys, in others more or less 
 com])lctely transverse to them, occnr, with constant evidence of the 
 carriafjo eastward in (piantity, but not to a very }?rc,it distance, of 
 rock-fraj?ments — <;:ranitic rocks, for instance, havinjij bee)i moved 
 sonio miles eastward and left scattered on the glaciated surfaces of 
 basalt-tlows. The evidence of a previous movement of ice westward 
 down tho Tanyabunkut valley and towards the coast through tho 
 Salmon-river gap, owing to its sheltered position, has not been 
 obliterated by tho subsequent eastward flow, which all the evidence 
 tends to show must have been of short duration. 
 
 iSouth-ivest('r)i or Main Branch vf the Nechacco liiocr (lat. ~hi° 25', 
 long. 125° 10'). — The river here issues from a large lake called 
 Na-tal-kuz l)y the Indians. Tho lake lies transversely iti a range 
 of hills which luus a general north-west and south-east course, 
 parallel to the Coast range and other main features of tho country, 
 but rising in the centre of a plateau region. To the south-cast 
 these hills become mountains about 2fM»0 feet in height above the 
 plateau in 8(>'"" instances. The lake is damn: j J by morahio-raaterial 
 with rocks ? ring in its sides ; and the surface of a small isolat;od 
 rocky hill n<. its lower or eastern end shows heavy glaciation from 
 west to east, parallel to the general course of the valley. Eaat of 
 the end of the lake the Nechacco cuts through a mass of moraines 
 which covers a stretch of country probabl.- at least five miles square. 
 The moraines are very little modified, a'.iJ wonderful in size and 
 state of preservation (fig. (>). The most prominent form ridges miles in 
 length, which, though wavering a little in direction and of variable 
 height, sweep round to the north-ctvstward in broad curves, to the 
 direction of which the rivor conforms for some time. The ridges 
 are steep-sided, sloping fro(]uently at an angle of 3U" to the Iwttoms 
 of the narrow sinuous valleys which soarate them, and are from 
 100 to 2U0 feet in height. The best-marked ridges are evidently 
 the successive lateral moraines of a glacier-tongue gradually de- 
 creasing in width. Besides those, however, there are occasional 
 fragments of transverse ridges, blunter and broader, apparently 
 remnants of terminal moraines formed when tho glacier nearly 
 equalled the valley in width. 
 
 It cannot be certainly atHrmcd thai the glacier causing this dis- 
 play of moraines did not owe its origin to the low range above 
 mentioned. Taking, however, all tho local circumstances into 
 account, and especially the small gathering-ground afforded by this 
 range, it a])])ears more probaldc that the Coast-Range glaciers must 
 at one period have pushed a short distance through the gap in which 
 the lake lies. 
 
 Still further north, on the 54th parallel, the valley contiiining, 
 from west to east, Franijois and Frascr Lakes and tho lower portion 
 of tho Nechacco river, runs from near tlie eastern base of the Coast 
 range (o the Frascr in a reniarkal»ly direct lino, Fr^itK^ois Lake, 
 further west, is, bv mv track-survev, fiflv- seven mile-; and three- 
 
11(5 OKOKOK SlKUrER DAWSON ON mi: 
 
 quarters in Iciijith, with a widtli of from one to two iiiid a half or 
 three miles. It is slightly ^iuuous, tlic opposite sides generally 
 rcmaiiiing jjarallel, deep, and in ])art surrounded by Htcoj) hills, 
 especially toward the lower end. The stream dischar<rin^ Francois 
 Lake runs eastward to Fraser Lake, eleven miles in length ; and this, 
 again, sends its waters by a very short stream to tlie Nechacco at its 
 (ireat Bend. There is a remarkablo absence of traces of ite-action 
 in the valley of Franeois Lake ; and though both shores were care- 
 fully examined, no more certain sign of glaciation than the general 
 form of some rock-masses was seen The nature of the rocks may 
 to some extent explain this ; but the material of the lake-sliorc is 
 remarkably local in character, being composed almost invariably of 
 the immediately underlying rock. Following the valley eastward, 
 however, at the lower end of Fraser lake, on hard dioritic rocks, 
 marks of very forcible glaciation are found. Ice has hero evidently 
 been pushing up out of tlie lake-bed, over a rock-surface, under great 
 pressure, and has been forced in some instances through little rocky 
 viilleys at a considerable angle to its mean direeti(»n, which is 
 remarkably cojistant at S. >S8° E. to S. DJi" E. On nearly vertical 
 rock-faces on the ni^rthern side of the lake i)arallel grooving may be 
 seen to run castwanl, and slope upward at a considerable angle to 
 the water-line. ().i Hat surfaces near the shore, many instances of 
 prcglacial rock-hollows, with rougli western and rounded cfiatern 
 margins, were found. The glaciation continues ap])arent for some 
 miles beyond the eastern end of tlie lake ; and its direction is also 
 shown by the fact that blocks of the diorites have been carried 
 eastward until they overlie the newer basalts. 
 
 I do not think any of the hills bordering Eraser Lake reach an 
 elevation of lOUO feet above it ; and its western half is surrcuinded 
 by low country. It is difhcult. if not impossible, to account for the 
 glaciation, uidoss it be supposed that a glacier stretched thus far 
 from the Coast range, nearly one hundred miles distant. The 
 absence of boulders from the mountains in the immedijite vicinity of 
 Frani^'ois Lake is singular ; 1)ut that of the ordinary erratics, so plen- 
 tifully distributed over all this region, is ecpudly excejjtional. These 
 facts may perhajis bo explained by supposing that ttie glacier swept 
 the valley completely clear of the debris due to Ihe earlier drift, 
 while for some reason the material moving with the glacier itself 
 was very small in amount. 
 
 This case and that of the Ui)per Xcchucco do not give such in- 
 dubitable proof of the action of ice from the Coast range as those 
 before descrilted in the region further south ; yet, taking into ac- 
 comit the circumstances in both instances, they scarcely seem ex])li- 
 eabl(5 otherwise. From many other localities, however, in wdiich 
 moraines of greater or less ini])ortancc are ])reserved, it Wf)uld ap- 
 pear i)robable that at one time accumulations of ice sufttcient to 
 produce moraines by their movement lay as well on the more ele- 
 vated portions of the interior plateau. 
 
 In all the moraines observed, tin* normal material differs little 
 from that of the Boulder chn ; or when a difl'crence obtains, it is in 
 
SUrEIlKXCIAl, (iKoLOUY 01'' HKIllsn (:»Lf.\l HI A. 1 17 
 
 the direction of f»reater wator-agciicy in its [)roi)aratioii. The stones 
 are rounded and waterworn as a rule, heavily ^l^iciatod in a few 
 iustances, and mixed with hirj:;e anjj^ular ira>,'nients only when those 
 have been abundantly produced by some hill or cliff near at hand. 
 There is also much evidence, especially about Tatla hake, the ^fazco 
 watershed, and on the Necliacco, tendiuj;: to prove that the {gra- 
 dually retrcatiiif? jjlaciers piled up some, at least, of those gravelly 
 moraines in water, which was decreasing in dejjth at the same time 
 with the diminution of the supply of ice. This evidence is chieily 
 derived from series of flat- topped or water-wasted moraines in 
 such localities and so arranged as entirely to preclude their being re- 
 ferred to esker ridges. 
 
 4. Mode of Olaciation and Formation of xhe ScrrEUFiciAL Deposits. 
 
 In the foregoing I have endeavoured to give a short accoxint 
 of the glacial ])henomena and superficial deposits of Ih'itish Coliiinbia, 
 80 far as I have examined them, entering into some detail in a few 
 important and typical eases only, with the view of bringing the 
 facts as they occur, in this hitherto little-known region, to the 
 notice of geologists. Some unceitainty has been ex])ressed as to 
 the action on a large scale of glacial ice on the north-west coast 
 of America, which may n(jw, I hope, bo removed, at least so far 
 as regards Uritisli Columbia. 
 
 Professor Whitney, in the ' Proceedings of the Academy of 
 Natural Sciences of California,' 1808, says that there is no evidence 
 in California of a general glacial c])och, such as that which att'ected 
 the Eastern States. He extends this conclusion to Nevada and 
 Oregon, and, following information received fioni Messrs. Ash- 
 burner and Ball, further remarks that no evidence of northern 
 drift has l)een detected even so far north as 15ritish Colum1)ia and 
 Alaska. Professor Dana, in the last edition of his ' Manual,' (piotes 
 Whitney's statement of the absence of northern drift, at least as 
 far north as Oregon, but alludes to the grooving on Vancouver 
 Island as possibly indicating general glaciation there. IVofcssor 
 Le Conte, however, speaks o^' noiihern drift near the Columl)ia 
 river, east of the Cascade range*; while ti!ibl)s writes of the 
 country in the vicinity of Puget Sound, somewhat further north, 
 that it is "one vast maws of moditicd driif't, which he further 
 asserts to have, at least in part, a northern origin, on account of the 
 nature of the erratics. These must havo been dejiosited in con- 
 nexion with the southward extension of the Strait-of-Georgia 
 glacier, or by floating ice after its retreat. 
 
 T)r. 11. lirown, in a paper " Oti the sui)posed Absence of Drift on 
 the Pacific S]o])e"'J, combats the statements of Whitney aiul others, 
 »]uoting especially Mr. Eauerman's observations on the coast- and 
 
 * AiikJomiti. 8fi. itiid Art.-<, ^hl^(•ll mikI Auril, l*»7t. 
 
 I .loiM'ii. .Am. (ipul. Stic. 1*^71. 
 
 ; Am. J'liuMi. I?ci. niicl Ails. l^iT'"*, p. ol>^. 
 
118 (iKOKUIC MDRCEU DAWSdN (iN THE 
 
 gliiciiil pheiKimc'iia which came uudor liis own notice on Vancouver 
 and as far north ns the (iuccn-C'harhjttt! Irthinds. 
 
 In rofjard to Alaska, Dull writes*, aftei" describinpf his route 
 across the breadth of that territory ; — "• 1 lia\'e carefully examined 
 the country over which I have passed for }i;laeial indications, and 
 have not found any efleets attributable to sueh aj^encies; " and 
 aj;;aint, "Three years' exploration, with a stron<; disposition to 
 develop the facts of the case, foiled to obtain on the shores of Norton 
 Sound, or in the valley of the Yonkon, any evidence whatever of 
 such action." If Alaska has indeed escajtcd glacialion, while 
 British Columbia and the adjacent re<;ions have been so shajied by it, 
 tho fact is an extremely remarkable one. It must ^*o observed, 
 however, that Mr. Dall lias failed to notice (be evid^ of glacial 
 action in the inlets of tlie coast, uiul, indeed, affirms that no traces 
 of sueh opiiear^:; Avhilo my own observations, confirmed and 
 extended to a wider area by those of Mr. Hichardson, show that 
 fjlacier-work on a gigantic scale has occurred in them. In endea- 
 vouring to exjdain by any satisfactory scheme the sequence and 
 cause of tlie phenomena, one meets with many elements of uncer- 
 tainty and complication, arising not only from the very pronounced 
 and varied physical features of the country, but from our as yet 
 very imperfect knowledge of great regions of the interior. It may, 
 however, be well to give such conclusions bearing on these points as 
 a study of the region has enabled me to form. 
 
 There is little doubt that the glaciation from north to south is 
 the earliest fact of tho ice-ago of which any record has yet been 
 found ; and the (juestion arises as to whether this should be attri- 
 buted to glacier-ice as such, or to floating, ice. If to the former, it 
 cannot bo due to local action of any kind, as some of the localities 
 where grooving is observed are elevated above the whole sur- 
 rounding country, and the direction of movement recpiired is con- 
 trary to the ger.eral inclination of the broken central jilateau, and 
 towards a region in the vicinity of the l!»th parallel which is nearly 
 blocked with irregularly traversed mountain-ranges. For reasons 
 stated in a former investigation of tho glacial phenomena of tho 
 Great I'lains, I do not believe the theory of a polar ice-cap to bo 
 applicable to the western jtart, at least, of North America ; but it 
 must bo confessed that the indications noted in some places in British 
 Columbia more nearly answer to the kind of traces which such an 
 ice-cap would bo expected to leave than any thing 1 have elsewhere 
 seen. The ])ortion of the supposed ice-cap entering the C(>ntral 
 plateau must, however, bo imagined to have passed as a ju'elimimiry 
 across the mountainous region to tho north of the iSkecna and about 
 the Findlay river, the I'eace-river gajis lying oblicjuely to its 
 course, and being besides not sufficiently large to admit the requi- 
 site (juantity of glacier-ice, even if the pressure was so applied as to 
 push it directly through the hollow. 
 
 * Am. Joiirn. Sci. niul Ai'(i», vol. xlv. p. 90. 
 
 t " OliMTV.ntions on tlie Oeolofjv .if Aiaslia." pub. in ' Alaska Coast Pilot," 
 ISC.O, p. liM). I ftp. rif. p, lOrr 
 
 1 
 
/ 
 
 SfPrUHriM. (ii:o|,(MiV ok IIKITISH CtiLUMUIA. 11<J 
 
 It is, liowcvor, ])().ssil»K' (l)ut in <iii(> dtlicr mannor n jj;ro:it glacier, 
 moving from north to south, may have filled tho central ])lateau. 
 Owing to the warm water of the great Ja])an current, with the 
 prevailing westerly and south-westerly winds and mountainous 
 character of tlie coast, the annual precipitation of moisture is very 
 groat, especially to the north. At Sitka (southern end of Alaska) 
 (he average annual de])th of rain and melted snow (from sixteen 
 years' o])servations) is SiJ-tlU inches, or within a fraction of seven 
 feet ; while the average number of days on which rain, snow, or 
 hail fell, or heavy fogs prevailed, is two hundred and foi-ty-five, or 
 two days out of three. It may ho suj)})osod that, under certain 
 not improhahle comhinations of conditions, the mountainous country 
 to the north, above referred to, became preeminently the condonscr 
 of the Northern Pat^itic, aTid, from tho mere accumulation of snow 
 and ice, the focus of glacier-action and point of radiation of great 
 glaciers. If the central plateau was ever filled thus by a great 
 glacier-mass, the ice must have ])oured southward through the 
 gaps on the 4!lth ])aridlel, and westward across the Coast range, 
 in a manner similar to that in which the ice su])])osed by I'rofessor 
 (ieikie to have filled tho (julf of liothnia must have crossed the 
 Seandinavian ]teiiinsula*. 
 
 If the first glaciation of tl\e central jdatcau is due to tho action 
 of glaciers as such, we should, however, expect to find remnants at 
 least of deposits like those elsewhere ascribed to sueh gigantic ico- 
 sheets, and not precisely res(>mliling that noticed on a former jiage 
 under the name of Boulder-clay. If these exist, they have not fallen 
 under my observation ; and in any case it appears necessary to call 
 in the action of water with lloatiiig ice to account for the formation 
 of the Boidder-clay, with its rounded pcb])les and irregularly distri- 
 buted erratics. It cannot have been laid down by glacier-ice ; foi 
 it is difficult to imagine the formation of material ■which is found 
 not oidy over plains but on exjjosed hill-slopes and summits, beneath 
 a great glacier which we find in other places engaged in scooping 
 rock-basins in the bottoms of valleys. It rests immediately on tho 
 well preserved glaciated surfaces, and, on tho above su])position8 of 
 an extension of the ice-cap, or great central-plateau glacier, may 
 have been formed during tho gradual retreat northward of the 
 decaying front of tho ico while the country was submerged to a 
 depth of over 5(t00 feet, either by access of the sea, due to general 
 depression, or by the formation of a groat lake covering the ])lateau 
 region, the passes of tho Coast range — those to the south, and those 
 of the Rocky Mountains to the east, being still blocked by local 
 accumulations of glacier ice. Tho movement of icebergs would 
 explain tho irregular distribution of the foreign mixed materials of 
 the deposit. Water-action, sufficient to account for the rounding of 
 the pebbles, may have occurred ; and the gradual diminution of the 
 glaciers in the various mountain-ranges may be su])posed to have 
 allowed the slow drainage of the lake, and given rise to tho great 
 systems of terraces. 
 
 * Oreiit Ice Age, p. 4t»4. 
 
Ii'o uKitn(;i: Mi;iti'i:i( itvwsinN on tiik 
 
 The stoppaj^o of all the gaps to ho great a hciglit, howovcr, in tlu> 
 various raii;,'o.s would imply a coonliualioii sc.ircoly within llio 
 boiiuds of piohal»ility ; and on grounds whicli aro statod in the pre- 
 ceding pages, and others which will shortly l»o referred to, it ajipeiirs 
 to nio :n<»ro probable that it was by depression of the land as a 
 whole, or elevation of the ocean, that the waters attained the level 
 they are known to have reached in the interior. 
 
 To explain tlie facts by the action of floating ice, icebergs or 
 pack-ice must be supjjosed to have entered the central plateau by 
 the low gap throuj;]! the Uocky Mountains in the I'eace-Hiver region, 
 and, reinforced, no doubt, by ice from local glaciers, to have travelled 
 south >i'ard under the inlluence of currents, wliich found exit by the 
 Frascr river-valley and other southern openings. A de])ression of 
 ;iU(.)0 feet would open a wide strait from the Arctic Ocean to the 
 Pacific, by the valleys of the IVace-Kiver country, continued south- 
 ward by that of the Friiser ; while sea-water standing at a height 
 ecpial to th maximum above stated would give dei)th enough for 
 very heavy ice, and would besides open other avenues in the llocky 
 Mountains, and many and wide ones through the Coast range and 
 to the south. If sucli ])alicocrystic ice iis that met with by the late 
 Arctic Exjiedition may bo supposed to have tilled the central biusin, 
 it will not 1)0 necessary to invoke the action of icebergs to account 
 for the simultaneous, or nearly simultaneous, production of the north- 
 and-south grooving, and deposition of the IJoulder-clay. It is 
 worthy of mention that in most phices where striatioii referable to 
 this system occurs, the country to the north is low, suggesting that 
 the localities may have formed islands on the southern margin of a 
 sea in wliich great ice-prossure may have occurred from tiiuo to time. 
 On the supposition of a submergonco of three thousaiul feot or 
 more, very important results might follow with regard to tho distri- 
 bution of oceati-currents. The Kamtschatku branch of the warm 
 Japan current would, no doubt, be greatly augmented in size, and 
 flow north-eastward through a widened liehring's Strait, possibly 
 accounting for the ajjparent absence of ghicial traces in Alaska. Tho 
 outflow of ice-laden polar water would be to the same amount in- 
 creased, causing a wide arctic current to flow southward in the 
 region now forming the Mackenzie river-valley. A part of this 
 would find exit across the great plains and by the lied- River hollow, 
 while a second branch, traversing the llocky Mountains by the Peace- 
 River gap, would flow down the length of tho plateau of British 
 Columbia,, accounting for the great transport of material and heavy 
 glaciation found to have occurred in both these regions. 
 
 On any of tho above theories the second advance of glaciers from 
 tho various mountain-ranges must be supposed to be the last phase 
 of which we have any record. These glaciers appear to have pushed 
 out among the water-rounded materials of some of the lower terraces, 
 after a period of somewhat greater warmth, and before the roeleva- 
 tion was complete, or while a lake, or series of lakes, dammed by 
 glaciers existed. The latter is not an unreasonable supposition when 
 the comparatively smtill height of water required at this period is 
 
SL I-l liKliHI. (ii:iil.niiV Ml liltlllsll (til.lMliU. \'J] 
 
 tiikoii into account. As llieso lute-^t yliii'icra retired, alter their 
 sliort udvuiico, the Wiittirs also appear tu litivc fjilk'H, tlio i»iirtl\ 
 wutor-niodifit'd moraine-mounds remaining as evideiiceH of tliis joint 
 action. 
 
 If glaciation of the nuiinliin<l by a <o'ci\\ northern ice-cap. whetljer 
 of polar orif^in or arisinj^ within the country itself, ever occurred. 
 Vancouver Isljind and the rcjjjion of the Strait ot' (ieorf;;ia must huv<^ 
 hoeu l)uried under u still fi;reater accumulation of ice; but if the 
 glaciation of the continent was effected during a .submergence of 
 40(10 or ')()(J0 feet, very little of the i.shiiul would rcinain above the 
 surface of the sea, and the holhiw between it and the (/oaHt range 
 would be lielow the level and sheltered from the action of the 
 floating ice. In either case, however, the dimensions attained l)y the 
 glaciers during their latest extension, taking into account the 
 favourable position with regard to gatheriug-gi^junds of the Strait of 
 (ieorgia, would appear to be (piite suflicii'nt to explain the forma- 
 tion of the great glacier of the Strait. 
 
 The su])poscd gctu-ral submergence of the region to a maximum 
 depth of ')27<-' feet may at first seem a very startling hypothesis, 
 though it may be softeiu'd by such reference to its iiiNignificanco 
 when compared with the dianu'ti'r of the gUibe as that used by some 
 of the advocates of a grcit northern ice-cap. It may, however, I 
 think, be said to have been shown in the course of a former examina- 
 tion of the facts of glacial ion of tlie (jreat I'lains to be extremely 
 probable, if not absolutely certain, that the whole interior of the 
 continent, from tlie Laurentiaii axis to the llocky -Mountains, was 
 sulmicrged, and that the sea rc'achcd a height of at least -iAW feet 
 on the Hanks of the latter range*. With this terrace, and some of 
 those described ]»y })r. Hector, those of Tatlayoco J.akc, in the Coast 
 range of IJritish ('olumlua. correspond as closely as can be expected, 
 taking into account the di>tan('e apart of the two localities (."iito 
 miles). Is it, then. ;5ur])rlsing that, in a region further north and 
 better suited for their preservation, water-nuirks should be formed 
 at a yet greater elevation of about !l<»() feet? To explain some of 
 the features of the last Glacial period, we are called U])on to repro- 
 duce mentally conditions of which we can scarcely hoi)e to apjireeiate 
 the magnitude : but it does not ap]icar that even .")(i()() feet of water 
 should be considered so vast a conc( ption as the like thickness of 
 glacier ice. In Eastern America few localities ])resent themselves 
 where the effects of subsidence to an amount eqtial to this can ho 
 studied. We find terraces, however, to a height of 142-") feet on the 
 J,auientian axisf ; and it is worthy of remark that a depression of 
 about the (vmount above indicated would serve to account for the 
 glaciation and erratics of the higher UKmntains of the Xew- Kngland 
 stAtes. 
 
 * QiKirt. .Toiini. Oool, Snc. vol. ixxi., 1S7.'). p. <>0:? : • (i('fil<i^\ jind Rpsoiirccs 
 ittlie4ltth Pjinillel,' p. 244. 
 ' Cleology iiiid KcsoiirPcs oi'tlic 49tli PiiriiUel, \>. -'.'>i'i. 
 
iL'H utuKiii: MiiiuLii uawmin U.N riii: 
 
 '). SlM.M.\I!Y. 
 
 1. Tlic lUuracter of the roLk-striiiliou and iliitin<j; on the south- 
 oastcni jicniiisiilii of Vancouver Island shows that at ono time a 
 great i^hicicr .swept ovcm' it Iroiu north to south. Tlio j^laoiiT must 
 have tilled the Strait of (ieorgia, with a hrcadth, in some ])!acc8, of 
 ovor ')(> miles, and a thickness of ice near Victoria of considerably 
 over tino feet. Traces of the s^lacior arc also found on San-Jnan 
 Island and tlio coast of the mainland. 
 
 2. The deposits immediately oveilying the glaciated rocks, besides 
 liard material htcally dcveloi.ed, and prol>ably representing moraiue 
 jirofdiidi', consist of sandy clays and sands, which have ])ecn arranged 
 in water, and in some place ? contain marine shells. These, or at 
 least their lower lieds, were i)robably formed at the foot of the 
 glacier when retrc;iting, the sea standing considerably higher than 
 at i)respnt, 
 
 li. Observations in the noithern part of the Strait of Georgia, and 
 the fjords opening into it - where the sources of the great glacier 
 must have been ~ show ice-action to a height of over liOOn feet on 
 the mountain-sides. The fjords north of the Strait of Georgia show 
 similar traces. Terraces along the coast of the mainland arc very 
 seldom seen, and have never ])een oljserved at great elevations. 
 
 4. In the interior i)lateau of IJritish Columbia there is a system 
 of glaciation from r.oi th to sonth, of which traces have been obKer\'ed 
 at several localities above IHHH) feet, Sul>se()uent glaciation, 
 radiant from tlie mountain-ranges, is also found. 
 
 '). The superficial deposits of the interior may be classified as 
 unmodified and modified. The former, representing the Honlder- 
 clay, hold many water-rouiub^d stones, with some glacier-marked, 
 and occnrs at all heights ii]) \o over o(><i<> feet. The latter charac- 
 terize nearly all localities below IJOOO f(>et. and are most extensively 
 develo])ed in the northern low country, where they appear as a fine 
 white silt or loess. 
 
 (>. The interior is marked with shore-lines and terraces from the 
 present sea-level np to 5270 feet, at which height a well-marked 
 beach of rolled stones occurs on 11-ga-ehnz Mountain. 
 
 7. Moraines occur in great numbers. Some of the moraine-like 
 accumnlations may have been formed in connexion with the north- 
 to-south glaciation. ilost of those now seen, hoAvever, mark stages 
 in the retreat of glaciers towards the various mountain-ranges. 
 The material of the moraines rcsemldes that of the JJouldcr-clay, but 
 with water-rounded stones even moi'c abundant. 
 
 S. The sequence of events in the interior region has been :»— 
 glaciation from north to south, with doi)osit of ]ionlder-clay ; for- 
 mation of terraces ])y lowering of water- surface, accompanied or 
 followed by a warm period ; short advance of glaciers from the 
 mountains contera])oraneously with formatiou of lower terraces ; 
 retreat of glaciers to tlieir present limits, (ilaciation of ^'ancouver 
 Island may have occurred during both the first and second cold 
 periods, or during the second only. 
 
MI'i;UKI(lAL (ll'.ifLuuV UK llhlTlSU COI-I'MMIA. \'S4 
 
 0. If tlio norlh-to-soiitli ^liiciulioii lias licoti in-odiicod by glucler- 
 ice, it must Imvc been either (o) 1»y the action of a great northern 
 ice-cap (against which grave difficulties appear), or (7>) by the 
 accumulation of ice on tlio country itself, osjK'cially on tlic moun- 
 tains to the north. In either case it is jirobable that the glacier 
 filled the central plateau, and, bi'sidos i)aBsing southward, i)as8cd 
 seaward through the gaps and fjords of the Coast range. The 
 "Roulder-clay nuist have been formed along the front of the glacier 
 during its withdrawal, in water, either that of the sea, or of a groat 
 lake produced by the blocking by local glaciers of the whole of the 
 valleys leading from the jjlatoau, to a depth of over 5000 feet. 
 
 10. If general submergence to over 5000 feet bo admitted, the 
 Japan current would flow strongly through liehring's Strait, and 
 over part of Alaska, while arctic ice-laden water, passing south 
 across the region of ibe (ireat I'lains, would also enter the central 
 plateau of British Columbia, accounting for the north-to-south 
 glaciation and simultaneous formation of the Uoulder-clay. 
 
 EXPLANATION OF PLATE V. 
 
 Outline Map of British Coliinibiu, showing the portions exceeding an elevation 
 of 3000 feet above the sea-level, the general direction of the principal 
 mountiiin-rnnges, and the former exteneion of glaciers trom tne Coast 
 Mountains. 
 
QiiHii .i-'.uii (Vol Sor Vol .XXXIV P! V 
 
 l.t:j 
 
 III- 
 
 .-•l- 
 
 
 X3 \ 
 
 9? M>>/^^ 
 
 i .')0 
 
 I<> 
 
 'i.;i 
 
 BRITIS 
 
 ATI/ /cw/. (Itllill 
 
 /hnuji'Jnnliriii/'n ' 
 + liidiaiUwIitrtliisI K 
 Mi/tuitiii/i iiliina 
 
 riiUlii;ii,l 
 
 ".() 
 
 1:1 
 
 I)! 
 
 i;»u 
 
 ii;t 
 
 III- 
 
 •wi 
 
 ■•' £tC L -H tV fcfj'Cr';. i' vCjvtjur Capcen 
 
);!•_' 
 
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