• Rhaetic. 



T 22 GR1ESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



Above it follows the uninterrupted series of strata of the lowe , 

 Middle and upper middle and upper trias overlaid by a great 

 trias of the Niti pass. thickness of the rhaetic system. The path which 

 ascends the Niti pass runs through a dry ravine (fig. 17) during 

 the lower half of the ascent, and exposes the beds well. The lower 

 portion of the triassic beds (all yielding fossils) are greatly disturbed 

 and there is considerable local crushing. But nevertheless the general 

 sequence is seen to be the same as in the measured section of Shal 

 Shal (page I38ff). On the Otoceras beds follow hard grey limestones 

 with Muschelkalk species, which are overlaid by hard black splintery 

 limestones and shales with traces of fossils only. The upper portion 

 of the triassic system is formed by a light grey hard limestone in thick 

 beds, with rust-coloured flaggy limestone beds, on which immediately 

 follows the great thickness of thick-bedded limestones and dolomites 



which I consider to belong to the rhaetic. The 

 bottom bed of it is a pink and variegated colour- 

 ed cellular limestone seen in most sections near the base of the 

 rhaetic. In the middle portion of the rhaetic, rather more than half 

 way up the Nitupass, beds with many fossils of Koessen type are 

 seen. Higher up another parting in the dolomite series, in which 

 sections of Megalodon sp. are frequent, appears, in which Belemnites 

 crumble out in fragments. This bed, a dark shale with partial oolitic 

 structure, I have also noticed near Bara Hoti at the foot of the Ma 

 Rhi La (pass). 



Sections north of the Niti pass. 



The top of the pass is formed of beds with Rhynchonella sp., Tere- 



bratula sp., etc., and on the top of it is piled an 



enormous thickness of light-coloured limestones 



with bright reddish beds and nodular intercalations. They are seen 



to form the cliffs on each side of the pass, stretching far away towards 



the jagged points of the Silakank south of it. 



Mere fragments of fossils picked up in these great heights show 

 that this portion of the limestones must be looked upon as liassic* 

 Many of the fossils contained in it are of liassic types, whilst others 

 ( . 122 ) 



