1873.] DREW UPPER-INDUS BASIN. 457 



are no marks of littoral action, no beaches or beach-marks — which 

 would necessarily have been made, and, in the general unaltered 

 state of the surface, have remained. Again, the strata are often 

 or generally seen to be not exactly horizontal ; they have a slight 

 dip down in the direction of the drainage. This slope of the beds 

 is sometimes with difficulty perceptible, but is often seen to be 

 one or two degrees and sometimes more. The surface of the terraces 

 or flat slopes in the same direction ; and that direction varies as 

 much as the course of the valleys themselves changes. The relation 

 of these high-level deposits to alluvium in lower portions of the 

 streams (such as will next be described) increases the reasons for 

 connecting them with river rather than with marine action. 



The alleged inadequacy of existing streams to form such a deposit 

 as that 500 feet of pebbly alluvium I see no reason for. My expe- 

 rience of streams convinces me that their ordinary daily work in 

 many cases, and in others their work in the spring time, is to bring 

 down from the mountains, and to bring into form and deposit in 

 their beds, just such material as that. When a stream once gets a 

 tendency to raise its bed, there is no reason why it should stop at ten 

 or twenty feet, nor why, as long as there are mountains behind to 

 be wasted, it should not go on doing the same for 500 feet ; only it 

 must raise its bed not at one part of its course only, but generally 

 far up and down the valley. Such an alluvium, then, as de- 

 scribed, I put down to the action of the very stream that now flows 

 at the bottom of the ravine cut through ; it may, indeed, formerly 

 have had a greater volume and force from the existence of a dif- 

 ferent state of climate. Nor is there any greater difficulty for the 

 same stream to have cut the ravine through that alluvium than to 

 have deposited it ; for the deposition at that portion of its course 

 implies the bringing of material of a certain character down from 

 above ; the cutting away of the alluvium only implies a carrying of 

 that same material further down towards the sea. The reason why 

 a stream should at part of its course at one time accumulate material 

 and at another time carry away the same material is well worth 

 seeking for ; but of the fact that streams do so I have no doubt. 



Two days' march to the south-west of the place of the last- 

 described alluvium, on another branch of the Zanskar river, is 

 a partly similar deposit. Here, for ten miles or so, the valley 

 that leads down from the Bara Lacha Pass, between mountain- 

 spurs, is a rather narrow flat (at a level of about 15,000 feet) 

 sloping gently to the north-east, the way the drainage runs, and 

 cut through by a ravine to the depth of about 200 feet, which 

 exposes the beds of alluvium which make up the substance of 

 the flat of the plateau down to the present level of the streams, 

 and perhaps lower still ; for the rocky base is not exposed. Other 

 streams join the main one from both sides ; and it is impossible 

 always to say to which of them parts of the alluvium are due ; in 

 truth the substance of both must have been intermingled and inter- 

 stratified. I wish particularly to note a phenomenon observed 

 here, the meaning of which shall be discussed when a similar one 



