6o4 ELLSWORTH HUNTINGTON 



came into play by which a cold film of fresh surface water, due to 

 melting ice, was displaced by warmer, more saline water from below, 

 and thus the remaining ice was quickly melted. 



Glacial origin of the basin. — It has been stated by Drew' and others 

 that the basin of Pangong is due to the damming of an old outlet by 

 fans from tributary torrents. The old outlet is evident, a broad 

 U-shaped valley extending northwestward from the western end of 

 the lake; and so, too, is the supposed dam, a large fan, 1,500 feet in 

 radius, having its lowest point 90 feet above the lake, and located a 

 mile from the latter at the mouth of a small tributary from the south. 

 The fan forms the divide between the Indus River and Pangong 

 Lake, but it does not appear to have been the cause of the formation 

 of the latter, but rather to have been able to grow up because the 



South. 



Fig. 6. — Cross-sections of the outlet valley of Lake Pangong drawn to true scale. 



.4-Zy=section at the fan, at the divide between Lake Pangong and the Indus. 



C-/> = section where the rock lip is most plainly visible. 



£-/? = probable section of the rock below the fan, including a glacial knob. 



G''= gravel. 



Z.c=lacustrine deposits. 



/,.?= bed-rock, chiefly marble. 



former stream from the Pangong region ceased to flow. The cross- 

 sections of the valley shown in Fig. 6 illustrate the matter. The line 

 A-B shows the conditions at the divide, and so far as it alone is con- 

 cerned, the valley might have been dammed by the fan. The lower 

 section, C-D, however, half-way from the divide to the lake, shows 

 quite a different state of affairs. At this point the flat bottom of 

 the broad, steep-sided valley which once served as an outlet is over 

 600 feet wide; more than 500 feet consists of sohd rock, Ls, 20 of 

 soft lacrustrine material, Lc, and the remaining 90 of gravel, Gr, 

 deposited by the insignificant wet-weather tributary flowing from 

 the divide to the lake. Thus the Pangong basin appears to be 



I F. Drew, The Jiimmoo and Kashmir Territories. 



