1873.] DREW UPPER-INDUS BASIN. 445 



In Ladakh taluses of both these kinds are everywhere to be seen ; 

 the great bare rocky surfaces give rise to very fine examples of this 

 stage of denudation ; and of each can one recognize the source, 

 either the overhanging cliff from which the stuff has immediately 

 fallen or the scored surface of the mountain down which the collected 

 material has rolled. 



The talus seldom rests high up on the mountain-sides : its foot 

 reaches to a valley, which may be one of the main ones, or may 

 be a steeper and sloping tributary ravine ; and from that the slope 

 of loose stones extends regularly upwards, often for 1000 or 2000 

 feet. 



A peculiar case, peculiar more for the degree to which this kind 

 of action has been carried than any thing else, occurs on some com- 

 paratively low granite spurs near Leh, the capital of Ladakh. There 

 the rock, disintegrating, has formed a talus at its foot, which, in- 

 creasing and growing up with successive additions, has risen gradually 

 till the slope of the loose stuff has almost reached the summit of the 

 cliff, of which only a lip, as it were, can be seen above : this must be 

 due to continued action of the disintegrating forces and to the re- 

 sulting talus being left undisturbed by any other denuding agent. 



Now and then I have seen a talus that has become consolidated 

 by a solution and cementing of the calcareous material it was com- 

 posed of; and then, being by later changes partly denuded, there has 

 been left some of this hardened breccia stuck high up on the face of 

 the mountain, puzzling one at first to account for its position. 



One other peculiar form put on by taluses, though not, as far as 

 I have seen, occurring on any large scale, may be mentioned, as one 

 likes to account for the smallest detail of stone-arrangement that one 

 sees. I have spoken above of snow and rock together contributing 

 to make a talus : sometimes it happens that a talus of snow forms 

 first, in much such a position and form as the stone-heap itself might 

 acquire ; and then upon this snow-heap rolls down the loosened stuff, 

 which therefore finds rest only at the foot, round the edge, of the 

 snow-talus ; the melting of this in summer leaves a heap of stones 

 which may be of considerable height, though it is not very likely to 

 increase by additions in successive seasons. Such circumstances as 

 these should be borne in mind when one meets with isolated heaps, 

 not far from the mountain-side, which might otherwise be taken for 

 moraine-heaps. One other result I have noticed : the heap at the 

 foot of the snow talus is not unlikely to take the form of part of a 

 ring abutting at its ends against the mountain, and thus enclosing a 

 hollow which will become the basin of a little lake. There is a 

 lake 40 yards across, which I could account for in this and in no 

 other way, some miles above Pukarkot, in the higher part of the 

 Astor valley. 



Third, Alluvial Fmis. — The accumulations to which I give this 

 name are of great prevalence in Ladakh, and are among the most 

 conspicuous forms of superficial deposits. They are found at the 

 mouths of side-ravines, where they debouch into the plain of a wider 

 valley. I will take a first example from the valley of Nubra. This 



vol. xxix. — PABI i. 2 G 



