﻿1851.] STRACHEY — GEOLOGY OF THE HIMALAYA. 



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I have nowhere seen anything having the appearance of an ancient 

 beach or sea-margin along the edge of this plain, which may probably 

 be accounted for by the extreme violence of the rains, which is always 

 greatest over the first slope of the mountains. On one occasion I 

 myself measured a fall of one inch of rain in about twenty minutes ; 

 this was at Hardwar, where the Ganges leaves the outer hills. 



In proceeding with my explanation of the geology of these moun- 

 tains, it will, I think, be desirable that I should follow with a certain 

 amount of detail some one particular line of section, rather than 

 attempt to give a general account of the whole country. I shall in 

 this manner be better able to distinguish between what is matter of 

 actual observation and what of speculation. The line that I shall 

 take for this purpose (passing S.S.W.-N.N.E. between 79° and 

 80° 30' E. long., see Map, Pl. XVI.) is selected only because it is 

 best known to me, and not that it appears to exhibit a normal state 

 of things better than any other : too much stress, therefore, must not 

 be laid on its details, and it consequently seems desirable that as I 

 proceed I should point out such generalizations as seem to me to be 

 borne out by the observed facts. 



I may also here mention, that the direction of the strike of the strata 

 is usually not far from that of the chain generally, and in this parti- 

 cular portion of it W.N.W. to E.S.E. ; also, that the line of section 

 that 1 shall follow is on the whole nearly perpendicular to the strike. 



The transition from the plains to the mountains is sudden and well- 

 defined. A line of hills, called the Siwalik or Sub-Himalaya Range, 

 and well-known to geologists by the striking palseontological discove- 

 ries made there by Dr. Falconer and Colonel Cautley, rises abruptly 

 and without any intermediate undulating ground from the apparently 

 perfectly level surface of the flat country. The deposits of which 

 these hills are formed seem to be sandstones, often quite unconsoli- 

 dated and generally very soft, marls and clays, and boulders and 

 gravel-beds sometimes forming conglomerates. The dip of the strata 

 is usually towards the general mass of the mountains, on my par- 

 ticular section being N.N.E., at an angle of 5° or under (see Sec- 

 tion No. 1, Pl. XVII.). A steep face, from which rise the highest 

 summits of this range, is thus turned towards the plains, while a long 

 gentle declivity slopes inwards and forms a shallow valley along the 

 general line of strike, by meeting the foot of the next line of hills 

 which runs on the whole parallel to the outer line, but from five to ten 

 miles further in. This longitudinal depression is, as may be sup- 

 posed, by no means continuous, but is broken up in some places by 

 the passage of the streams that drain the interior of the mountains, 

 in others by the confluence of the two ranges of hills that usually 

 form distinct lines. The lower parts of these valleys generally appear 

 to be covered with a deposit of boulders and gravel, that slopes some- 

 what steeply from the great mass of mountains towards the outer 

 range of hills, so that the whole of the bottom of the valley is con- 

 siderably raised above the level of the plain without. The drainage 

 of these valleys usually collects along their longitudinal axis, and either 

 falls into some of the larger streams that cross them, or less frequently, 



