Silakank pass. 



114 GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



The towering precipices which rise on each side of the Chor Hoti 

 pass are, as far as I could examine them, composed of the easily re- 

 cognized white quartzite (8). 



Returning from Tibet by the Silakank pass, I descended (moving 



almost due west) over the beds of the rhaetie 

 and trias beds, which (with their lowest permo- 

 trias members) I found to rest on the upper carboniferous. Without 

 any difficulty one may trace the latter along the face of the high cliffs 

 on the right side of the Silakank stream resting on the devonian 

 Coral-Wmestone (6), and with the underlying Silurians forming one 

 great palaeozoic group, structurally closely connected throughout. 



The projecting nose, or headland, near the junction of the Dhauli 

 Ganga and the Silakank stream shows a good vertical section through 

 the palaeozoic group (see profile, pi. 6). 



The white quartzite (8) suffered probably a certain amount of 



White quartzite want- denudation before the subsequent black Produc- 

 ing in some sections. ^ sha]es were deposited> and conseq uently the 



upper boundary of the quartzite exhibits at some places a rugged and 

 denuded surface, and is altogether wanting in one or two localities in 

 the Niti area. This is the case on the left side of the Dhauli Ganga, 

 north of Patalpani, where the white quartzite (8) is partially wanting, 

 the black Productus shales (9) resting immediately on the red Crinoid 

 limestone (7). 



Near Kiunglung, on the south slope of the Niti pass, the sequence 

 Kiungiung and north- of the carboniferous is quite normal, see figs. 16 



and 17), and the white quartzite (8) is strongly 

 developed. 



I was able to trace the quartzite over the broken hills far to the 

 north-west below the snow-covered peaks west of the Niti pass, and 

 found that there its upper beds alternate with some impure hard lime- 

 stone, containing some well-preserved fossils, amongst which Brachio- 

 pods, chiefly Producti, are commonest. The carboniferous series dips 

 37 to 40 north-east, and is conformably overlaid by the permo-trias 

 of the Niti pass. 



( i«4 ) 



