460 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 28, 



In the Chonglung ravine, a northern branch of the Changchenmo 

 valley, are, here and there, terraces of alluvium, 70 feet above the 

 present level of the water ; and at one spot, a meeting of valleys, 

 there is an alluvial plateau 200 or 250 feet high. In the Chang- 

 chenmo valley itself, in the ten miles from the place where the road 

 to Yarkand first reaches it, to Kyam where the hot springs are, one 

 sees alluvium at various levels ; I counted six terraces of alluvium, 

 all due to the Changchenmo stream, in 150 feet of vertical height : 

 these terraces occupied but a narrow width each ; for the greater 

 part of the breadth of the valley is held by the recent gravel, over 

 which the stream flows in many channels *. It is at this part that 

 occur the compound fans of the side streams, one of which was de- 

 scribed in an earlier part of this paper, as well as the fans with 

 valleys cut in terraces in them. 



Opposite Kyam, on the right bank, is a great vertical cliff of allu- 

 vium, about 200 feet high. A little lower down, at the place where 

 travellers to Yarkand ford the river, the river-cliff shows river- 

 alluvium of clay and sand covered, I think, by fan-stuff ; here is 

 repeated, in a more marked and, so to say, exaggerated form, that 

 phenomenon of highly inclined and curved beds of alluvium described 

 as occurring in the higher part of the basin of the Zanskar river. 

 Here in Changchenmo the strata are bent up, in some parts very 

 suddenly ; and, indeed, some are bent over beyond the perpen- 

 dicular. Only some of the strata have been so affected, the beds 

 below and above being flat. I can only account for these pheno- 

 mena in one way ; and I think the explanation will suffice. The 

 former extension of glaciers in the Himalayas is well acknowledged ; 

 and I shall start from it as from a determined fact, without going 

 into proof of it, though I hope to bring before the Society details 

 about it. If a large glacier had its end at the spot where this un- 

 usual form of alluvium now occurs, it must have had a course of 

 near forty miles, whether it originated in the northern or in the 

 eastern mountains : immediately in front of such a glacier alluvium 

 would probably have been forming in considerable quantity; it is open 

 to one to suppose that the bed of the stream immediately in front 

 of the foot of the glacier was rising by means of such accumulations. 

 During that time the glacier may have risen on to such alluvium by 

 encroachment forward, or it may have been lapped round by the de- 

 posit, or partly both. In any of these cases a further forward advance 

 of the glacier (such as may occur any year when the balance of 

 movement and waste is slightly disturbed) would be apt to press the 

 alluvium -gravel in such a way as to crumple it up, to force it into 

 curves, which may have been sudden bends near at hand, and 

 getting more gentle further off, the distance to which the effect was 

 felt probably varying with the thickness of the deposit acted on and 



* Spread both on this recent alluvium and on a terrace 15 or 20 feet above 

 it, but not interbedded in the higher deposits, are many large blocks of white 

 limestone, derived from the hills on the right bank higher up. How they came 

 where they are is not very clear. They may have been brought by unusual 

 sudden floods, or, perhaps more probably, by river-ice. 



