8o 



GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



The system of beds which I have separated on the map and in my 

 sections as cretaceous, form in all the sections hitherto examined by me 

 a connected complex of strata, within which I could distinguish at 

 least two horizons. These are in descending order: — 



b. — White or light grey limestone, marly here 

 and there, containing marine upper creta- 

 ceous fossils. 



a. — The above rests conformably on a series of 

 beds, amongst which a silicious grit or, 

 sandstone of brown to olive grey colour is 

 the leading rock. Fossils I found very 

 few and they were badly preserved. 



") "Chikkim" C 

 X limestone, i 



"Gieumal " 

 sandstone. 



Upper 

 cretaceous. 



Lower creta- 

 ceous includ- 

 ing perhaps 

 Upper Tithon. 



The series of sandstones and shales which are inclosed conform- 



a. Sandstone series. ably between the Upper Spiti shales and the 



limestone (5), are well exposed in the sections 

 between the Niti pass and the Sutlej in Hundes, and also in the 

 watershed between the latter river and the Laptel drainage. The 

 leading rock of the series is a grey quartz-sandstone, weathering 

 brown, thin-bedded and alternating with silicious greenish-grey shales, 

 which towards the upper portion of the series change into massive 

 grey quartz-sandstone. Fossils seem rare in this rock. I have only 

 a few badly preserved specimens of Belenznites, and I found these 

 in a ferruginous layer close to the boundary with the Spiti shales. 



From its stratigraphical position immediately above the Spiti 

 shales, not less than from its similar lithological character, I am in- 

 clined to believe that the lower beds of this division may be identical 

 with the Gieumal sandstone of Stoliczka. If so, the lowest horizon 

 of this sandstone division must be looked upon as upper tithonian ; 

 since it has been ascertained that part of the black Spiti shales are 

 of tithonian age (according to Nikitin), it can only follow that these 

 sandstones are younger ; and if so, I think it will be found that the 

 upper beds, which form the greater mass of this division are neoco- 

 mian. 



The cretaceous sandstone series of Hundes I found overlaid by a 



b. Limestone series. l»ght-grey, almost white limestone, which con- 

 « Chikkim" limestone. tains numer ous fossils, mostly Bivalves, none of 



( 80 ) 



