.%..
v«>
IMAGE EVALUATION
TEST TARGET (MT-3)
/.
^/i
1.0
I.I
|50 =
IIM
1.8
1.25
1.4
1.6
*»
_ f," _
►
VQ
<^
/#
/
0>^
%'> ^^ -^^
Photographic
Sciences
Corporalion
i.
^^
%
rV
<^
#x
^9>
\
o^
\j
fV"
23 WEST MAIN STREET
WEBSTER, N.Y. 14580
(716) 872-4503
%"■
m
iP MS)
WJ.x
CIHM/ICMH
Microfiche
Series.
CIHM/ICMH
Collection de
microfiches.
Canadian Institute for Historical Microreproductions / Institut Canadian de microreproductions historiques
\
\
V-
Technical and Bibliographic Notas/Notas lachniquas at bib!:ographiquas
The Institute has attempted to obtain the best
original copy available for filming. Features of this
copy which may be bibliographically unique,
which may alter jny of the images in the
reproduction, or which may significantly change
the usual method of filming, are checked baiow.
D
D
D
n
D
D
D
D
D
n
Coloured covers/
Couvertura de coulaur
Covers damaged/
Couverture andommagee
Covers restored and/or laminated/
Couverture restaurde et/ou peiliculde
Cover title missing/
>.e titre de couverture manque
Coloured maps/
Cartes giographiques en couleur
Coloured ink (i.e. other than b!ua or black)/
Encre de coulaur (i.e. autre que bieue ou noire)
Coloured plates and/or illustrations/
Plarc<ies et/ou illustrations en couleur
Bound with other material/
Relii avec d'autres documents
Tight binding may cause shadows or distortion
along interior margin/
Lareliure serree peut causer de rombtt ou de la
distorsion le long da la marge intdrieure
Blank leaves added during restoration may
appear within the text. Whenever possible, these
have been omitted from filming/
II se peut que certaines pages blanches ajouties
lors d'une restauration apparaissent dans le texte,
mais, torsque cela dtait possible, ces pages n'ont
pas M filmdes.
L'Institut a microfilme le meilleur exemplaire
qu'il lui a ate possible de se procurer. Les ddta'ls
de cet exemplaire qui sont peut-dtre uniques du
point de vue bibliographique, qui peuvent modifier
une image reproduite. ou qui peuvent exiger une
modification dans la m^thode normale de filmage
sont indiqu^s ci-dessous.
I I Coloured pages/
Pages de couleur
Pages damaged/
Pages endommagees
D
D
n
Pages restored and/or laminated/
Pages restaurees et/ou pelliculdes
Pages discoloured, stained or foxed/
Pages ddcolorees, tachetdes ou piquees
Pages detached/
Pages d^tachees
Showthrough/
Transparence
Quality of print varies/
Quality indgale de ('impression
|~n Includes supplementary material/
Comprend du materiel supplementaire
Only edition available/
Seule Edition disponible
n Pages wholly or partially obscured by errata
slips, tissues, etc.. have been refilmed to
ensure the best possible image/
Les pages totalement ou partieilement
obscurcies par un feuillet d'errata, une pelure.
etc.. cnt itt fiim^es d nouveau de facon a
obtenir la meilleure image possible.
Additional comments:/
Commentaires suppldmentaires:
Pagination is as follows : [355] - 360 p.
This item is filmed at the reduction ratio checked below/
Ce document est iWmi au taux de reduction indiqu^ ci-dessous.
10X 14X 18X 22X
26X
30X
y
12X
16X
2DX
24X
28X
:
32X
The copy filmed here has been reproduced thanks
to the generosity of:
Library,
Gaologieal Survay of Canada
L'exemplaire filmd fut reproduit grflce d la
g^nirositi de:
Biblioth«qua,
Commistion Gtelogiqua du Canada
The images appearing here are the best quality
possible considering the condition and legibility
of the original copy and in keeping with the
filming contract specifications.
Les images suivantes ont 6x6 reproduites avec te
plus grand soin, compte tenu de la condition et
de la nettetA de l'exemplaire film6, et en
conformity avec les conditions du contrat de
filmage.
Original copies in printed paper covers are filmed
beginning with the front cover and ending on
the last page with a printed or illustrated impres-
sion, or the back cover when appropriate. All
other original copies are filmed beginning on the
first page with a printed or illustrated impres-
sion, and ending on the last page with a printed
or illustrated impression.
The last recorded frame on each microfiche
shall contain the symbol ^^- (meaning "CON-
TINUED"), or the symbol y (meaning "END"),
whichever applies.
Les exemplaires originaux dont la couverture en
papier est imprim6e sont filmds en commengant
par le premier plat et en terminant soit par la
dernidre page qui comporte une empreinte
d'impression ou d'illustration, soit par le second
plat, salon le cas. Tous les autres exemplaires
originaux sont film6s en commenp ant par la
premiere page qui comporte une empreinte
d'impression ou d'illustration et en terminant par
la dernidre page qui comporte une telle
empreinte.
Un des symboies suivants apparaitra sur la
dernidie image de cheque microfiche, selon le
cas: le symbols — ^^ signifie "A SUIVRE", le
symbols V signifie "FIN".
Maps, plates, charts, etc., may be filmed at
different reduction ratios. Those too large to be
entirely included in one exposure are filmed
beginning in the upper left hand corner, left to
right and top to bottom, as many frames as
required. The following diagrams illustrate the
method:
Les cartes, planches, tableaux, etc., peuvent dtre
filmds d des taux de reduction diffdrents.
Lorsque le document est trop grand pour §tre
oroduit en un seui clichd, 11 est f\\m6 A partir
du Tangle sup6rieur gauche, de gauche d drcite,
et de haut en bas, en prenant le nombre
d'images n^cessaire. Les diagrammes suivants
illustrent la methods.
1
2
3
1
2
3
4
5
6
JUN 1 1 t<J34
[Reprinted from the
Mining and Metallurgical Section.
stated Mertitii^, Tueukty, January 12, /SgS.
i
:
SOME ILLUSTRATIONS of the INFLUENCE of GEO-
LOGICAL STRUCTURE on TOPOGRAPHY.
By Bexjamin Smith Lyman.
Capt. D. G. Robinson's excellent map of the Punjab Salt
Range and of the country northward finely illustrates in many
places the influence of the geological structure upon the face
of the country. The map was made about forty-five years ago,
more particularly for military purposes, and is on the scale of
a mile to the inch, with shaded topography. Certain portions
of the map are especially interesting from the distinctness of
the geological indications.
■ It « ■ t 1 1 I • »
356
Lyman :
[J. I'. I..
Near the ••astern edi^e of tlie inap, and about twenty miles
northwest of the town of Jhilam, several ridges {Plate i) bend
round so as to form the northeastern end of as many concentric
ellipses, with the long axis in a northeast and southwest direc-
tion. The ridges evidently consist of harder beds of rock sepa-
rated by softer beds that luiderlie the liollows between. In the
main body of the ellipse the harder rock beds seem to have so
steep a dip as to make the beds perhaps nearly vertical and,
therefore, nearly parallel on one side to those on the other.
But where the principal ridges curve round at the northeastern
end of the ellipse, a much gentler dip outwards is shown by
the great steepness of the inner slopes and the comparative
gentleness of the outer ones. ]\Iany of the subordinate outer-
most ridges have their crests worn down towards the small
streams that cut across them, aiul thereby form sharp little
peaks half way between each pair of those streams. The space
in the interior of the ellipse of the principal ndges appears to
be mainly filled with some level-bedded, probably old-alluvial
soft formation. Yet here, too, the small streams have cut
down into the steep dipping underlying rocks, and have
formed numerous narrow, short valleys parallel to the main
ridges, and showing the persistence of the same structure of
the older beds throughout the ellipse. It is plain that the ellipse
is caused by a saddle in the rocks, and that, if the rock beds
of the principal ridges were restored, so as to be continuous
over the central part of the ellipse, a form would result, closely
resembling an overturned ship or boat, of which the prow
would be towards the northeast.
Another place {Plate 2) within half a dozen miles east of
the Indus, not far from the northwest corner of the map, and
about twenty miles southwest of Attock, shows concentric
ridges in a somewhat similar oval shape, forming roughly a
complete ellipse half a dozen miles long, northwest and south-
east, by a mile and a half wide. In this case, however, it is
clear, upon careful inspection, that the rock beds do not lie
in the shape of a saddle but in that of a basin. For towards
the southeast end of the ellipse, and in a less degree along the
northeast side, the steep escarpments on the outer side and
• - . « ,
fc • • • <
• • • ' • t • • I "
»•«..'. - • ; . . •
• • • • . I , .
Jour. Frank, fnst., I'o/. r'/.AT, Afay, /SgS.
-Topography Indicating Geological Structure.
Part or a Mao of the Punjab Salt Range and Northward,
BY Lt. D. G.Robinson, Bengal Eng'rs,
1851-57.
Original Scale:- i mile to an inch.
ri.ATK I.
(L_y/»an.)
Topography Indicating Geological Structure,
Part of a Map of the Punjab Salt Range and Northward,
5Y Lt. D. G. Robinson, Bengal Eng'rs,
1851-57.
Original Scale:- i mile to an inch.
ri.ATK H.
May, i8y8.| (ivoloi^iial St nut lire and iopograpliy.
Vi7
tlu" i-(»niparativcly gentle slopes on the inner one show that
the (Hps are towards the center of the chipse. Alons the >onth-
western side the same thing can hkewise be (hseerned. hut the
(hps seem to he steeper, more nearly approaching the vertical,
and continue so for a couple of miles to the southwest, where
the lower rock beds become gradually covered up by the over-
lying alluvium-like horizontal softer beds rdready noticeil. A
couple of miles northeast of the ellipse similar indications show
that the rock beds form another nearly ])arallel basin, btu the
ridges are more broken up. rui<l the geological structure is less
easily made out. This basin is distinctly and narrowly closed
by ridges on the northwest, but opens out towards the south-
east, and the ridges Ijecome less continuous and less clear.
Between the two basins the rock beds are in the form of a
saddle, but very closely pressed together and broken up. so as
to leave the geological structure less obvious. It appears,
nevertheless, that the saddle broadens out towards the north-
west.
Still another place (Plate j) about twenty miles further
south, has numerous nearly parallel northwest and southeast
ridges, with a couple of the stronger ones bending rountl at
the northwest to form the end of an ellipse. Here again the
steep outer escarpments and gentler slopes towards the center
show that the rock beds are in basin shape. Along each side
of the ellipse they appear to be more nearly vertical, with the
two sides rather closely pressed together. Northward from the
end uf the ellipse the rock beds form a saddle of somewhat ir-
regular shape, and to the northeast another basin, the whole
so compressed as to be broken u[) into rather disjointed parts.
The alluvium-like upper soft horizontal beds also reappear here
to mask the underlying iiarder layers.
Yet one more place {Plate 4) in the Salt Range itself, near
its eastern end, shows a still more varied geological structure
within the space of a few miles. At the point marked
"Choombi pole" there is a curved nearby rectangular ridge,
with steep outer slopes and gentler ones inside, indicating a
small basin, broken through along the eastern side by the Bon-
har l\i\er. The riflgcs on the east show by their slopes stecj),
35«
/. \' in a II :
IJ. V. I.,
I)erh:i])s vertical, dips; on ilic west, p^cntlor (Hit-s towards tlie
middle of the Itasiii. and on tin- nortluvest still gentler, with
the crests formed into little peaks between the small trans-
verse streams. To the northeast of the central hasin the
ridp^es arc ron^dily concentric, lutt further on become rather
sharply antjiilar in their course, as if crushed totjethcr ruid
broken. To the north the main ri\er valley is \'ery nmch I'llled
up with the sauK- alluvium-like, soft, horizontal beds already
noticed, mostly covering up the harder underlying rocks, but
leaviujLi^ some of them visible in short ridges that betray not
only steep dipping beds but a continuance (it the partly
crushed and l^roken condition of the rock beds of the neighbor-
ing hills. Vet some of the principal curves of the more dis-
turlied rock beds are j^arallel to one another even at a distance
of sever.'d miles. This illustration has also been used in the dis-
cussion of the paper read by Prof. J. C. Branner before the
American Society of Civil Engineers last November.
It is evident that the carving out of the strongly-marked
ridges and hollows in accordance with the geological struc-
ture has l)een effected by water — the rains and streams — leav-
ing the harder rock beds to stand forth and the softer ones to
be eaten away where not protected by overlying hard ones. In
that torrid climate the water has acted mainly in its liquid form,
with the help of weathering in a moist atmosphere during part
of the year, but without tl.e aid of frost to disintegrate the
rocks. In some places lime rock may have been to some
degree dissohed away by the waters, but their action appears
to have been mainly mechanical.
The clear indication of basins and saddles within the small
space of a few miles is owing partly to the fact that the succes-
sion of rock beds, originally laid down as sand, silt or the like,
one on another at the bottom of the sea, and afterwards more
or less consolidated, is made up of a great number of not very
thick lieds or masses of harder rock separated by softer l)eds
that are likewise not in very heavy, thick masses; and partly
to the fact that the whole series has been so strongly com-
pressed and is of so yielding a character as to have been
crumpled into very numerous, comparatively small waves with
I
Jour. Frank, lusl., I'o/. CX/.l\ .Ua\\ /^g8.
Topography Indicating Geological Structure,
Part of a Map or the Punjab Salt Range and Northward, |
BY Lt. D. G. Robinson, Bengal Eng'RS. i
1851-57.
Original Scale:- i mile to an inch.
Pl.ATK III.
( I.yman.)
1
j_ . . ' " ' ■!
Topography Indicating Geological Structure.
1 , Part of a Map of the Punjab Salt R nge and Northward,
BY Lt. D. G. Robinson, Bengal EIng'rs,
! 1851-57.
Original Scale:- i milk, to an inch.
1 1 ' 1 ' 1 1 1 1 1
1 . 2 . 3 • 4.MILES 5
|^^^»^ -W^^mi/^^ieSmmms0^
^F|^^^H^BK^^'\'^^nut .^^^gBgn^^BH^m^BI ^B^InflB^BflK^lSr - v^ ."^^^wSi
■E^BRBHHjf^ '^^&^tSvmACdEmHIHHRS^sRQB^2^^"'^'^^^^^'^^^^MH
^Q^^mn^^D naaM^&^~' -^^a^JAf'WiMJEltf^wif^iJp <-^%Bg T'<5^'«32^^MJH^K
IH^^Pd^'^^^^^^^' ^^ V^B
riS^I^lBW^Bffv^.y^^»''fcW '/ ■ J fJ^^t^^^^^KLm
H^^H^nv^'^ -rx*^ ^^^^^.
i^ffl^^Wi^y<j^rj^^
HSiC *%^^^
^^^^^^^i^^Ki
BB^B«^I^EL3:^'\^'^>kx<^^^^?-7^Hi^ v^^^^??'^^'*''^^saBiiB?My^^^t^M^yLi
jSB^wSSKS^j^^^^^^^'^'^^^^^'^^^^J^^^^^^aB^^^KB^k
mS^^^^MS^^^^.4jifm' 1 "'?'r;?^^^^^^P^Ji|lfflJM
^^^fl^Kfl|^uM^^|BBjttHfiKfJW ^^^iS^^^ /-^!^i£^^k^£.i^^^^^^^fw^^^HlHKsfflR9MG^^B
■H^B^^HLSiM^t^^^Ztlv''' " ^rSHHS^'^/i^i ' W 'ff*Tr*-T ^it^B 'fiH^WHiiFfKt
JTlWHBnMifflirl WSm/Mlmm^^SWSSlPJmvm^
IHH^^i^H^^^^^HHBK :^^^BBtf!fa <4ni^.^ l^^wScfir'^'slQ ini^HHH^ailSwvi^dR
mB^w^B^al^r'i TBB^Ep^^^^MiWl^a
^H^aBiMl^MH^E^iCTX TfT ^c^" ^X"* *3BMSiiil5teiLL^iCT'^ inK^SH^n^T'V
I'l.ATK IV.
i
1
i
1
<
1
(
t
1
1
I
1
t
(
\
May, 18', S.] Geological Structure and Topography. >
little basins and saddles. These folds are. to be sure, irr^
larly combined and in many places fractured and crushed i .0
discontinuity. The overlying, more recent, still scft, level-
bedded, alluvium-like material of the plains partially masks
and obscures the geological structure of the underlying rocks,
but is cut through in so many places as not to conceal it alto-
gether. In spite of all the irregular crushing and the occa-
sional concealment, many of the saddles and basins can be dis-
tinctly seen, or without great difficulty discerned, thanks to
the mainly favorable circumstances.
In the Appalachian region of Pennsylvania the same indu-
ence of the geological structure upon the topography is ob-
servable on a much larger scale. The successive masses of
harder and softer beds are much thicker, the whole series much
stronger, stiller and less readily yielding, and the basins and
saddles much more extensive. The irregular crushing and
breaking of these great folds is less in proportion to the whole,
and the result is in the main an aggregation of comparatively
simple regular waves. Ijasins and saddles on a grand scale. The
topography indicates those large forms in the same general
way as the small ones we have been considering in the Punjab,
and has been of great service in the study of the geology of
Pennsylvania ever since the days of the first State Geological
Survey. The varied topographical effects of the long, narrow
basin-form and saddle-form were ably discussed by Lesley and
H. D. Rogers forty years ago, when the subject was new to
geologists. For the comparatively simple conditions of the
Appalachians did not exist in most of the European regions
where geological work had been done, and the outcrops of the
different geological formations and their structure had been
traced out more exclusively by means of their fossils, without
regard to the topographical indications, that exist mainly in a
less obvious degree.
The first impression was that the Pennsylvania topography
had been produced by an inunense flood of water, an ocean
let loose, flowing over the land and carrying away vast ([uan-
tities of earth and stones. In those days it was difficult to rid
one's self of the idea that great geological changes were almost
360
Lyman.
IJ. F. I.,
mstaniaiicously ])r()(lm-c(l liy treniciulons cataclysms or even
Iiy (lowiirii^lit ,sui)CM-iiatural means or miracles. The idea still
lingers amon.t;- men not familiar with ^-eolos-ioal matters that
snnic stnpendonN topoi^raphical resnlts have been eltected in
the t\viid<h'n^- of an eye by the "finger of God" — the expression
cited by I'rof. Uramier. I>nt all geologists now realize that the
scul])tin-ed relief of the monntains and valleys, even where most
astonnding. even tlie gorge of the Niagara or the canon of the
Colorado, has been accomplished in the lapse of thonsands of
_\cai-s ]>y the same agents, chielly rain and stream> of water,
that we see still in action abont ns.
It is i)laiii that tlie geological indications given bv the snr-
fai-c topogra])hy nnist ha\c great \alne of a practical kind, and
aid very nnich towards ascertaining both the general snbter-
ranean structure and the smaller details of either theoretical
iiUerest or economical importance. Jf coal or iron (jre or other
valuable mineral is known U) occupy a particular geological
horizon, a certain layer in a series of rock beds, such a series,
for exam])le, as we have in these Punjab illustrationr-., the jilace
of oiUcrop of that horizon or layer, with the useful mineral,
may in many cases be recognized merely by means c^f a careful
stndy of the topography, and often the general structure,
whether that of a basin or of a saddle, may be percei\'ed; even
though the surface of the ground may be so covered with loose
earth and broken stone as to onceal the dii)S and precise char-
acter of the solid rock l>eds below.
The Punjab illustrations of the inlluence of the geological
structure on the topography are interesting from their show-
ing so clearly the small basins and saddles, with freciuentlv
\-ery steej) dii)s, but occasionally geinle ones, and with the
repeated .alternation of rather thin harder and softer rock
I'.eds. partly l)uried under level-bedded, soft, alluvium-like beds,
in a region where the rock betis are in the main verv stronfrlv
coni])ressed and sharjily folded and often broken and crushed
together. The map is a striking example of the excellent geo-
logical results of faithful topographical work by surveyors who
were no doubt (|uiie unconscious of its ha\ing any signihcance
for ij\'( il< >L' A'.