6o6 



ELLSWORTH HUNTINGTON 



that there is any narrow inner gorge at the divide, and still more 

 improbable that one of the smallest tributaries, joining the main 

 stream in the gorge where the latter would be most powerful, could 

 completely dam it, especially as the fans of other larger tributaries 

 have produced no such effect. If it be supposed that the outlet has been 

 dammed by a moraine instead of by a fan, it is still necessary to assume 

 the existence of the same improbable gorge, and to explain how such a 

 gorge could ever come to exist. It is further necessary to assume 

 the existence of a completely concealed moraine, for in this part 

 of the outlet valley there is no trace of any such thing, although 

 glacial knobs show that ice once filled it, depositing moraines lower 



down. The theory 

 of a dam, whether 

 due to a fan or to a 

 moraine, seems un- 

 tenable. The only 

 alternative is that the 

 Pangong basin is 

 closed by a rock-lip. 

 The most satis- 

 factory explanation 

 of the formiation of 

 the lip seems to be 

 that the basin behind 

 it has been glacially 

 eroded. Another 

 possibility is that the 

 lip is due to warping 

 or faulting, but this may be dismissed for lack of evidence. There 

 is no sign of recent faulting in this region, nor of warping of the 

 kind demanded. As is evident from the map, the long, winding basin 

 occupied by Pangong and the other lakes is distinctly a river valley, with 

 no affinity to the type of basin due to crustal movements. Of glacial 

 action, on the other hand, there is abundant evidence, not only near the 

 lake, but down-stream in the outlet valley. Below Tanktse, 20 miles 

 from the lake, an old moraine from 500 to 1,000 feet thick extends 5 

 miles down-stream. The characteristic topography has been destroyed 



Fig. 7. — Glacial knobs in the mouth of the Pangong 

 outlet valley near Tonktse. Glacial smoothing is clearly 

 seen on the left where the fort A stands on a completely 

 isolated, well-striated knob. 



