PA1NKANDA SECTIONS. I 27 



many specimens of Modiola sp., Posidonia sp., Rhynchonella sp. } 

 followed, higher up (down the river) by shales which yielded nodules 

 filled by Belemnites sp., whole beds being made up of this fossil. 

 After this Ammonites come in again, mostly of upper Jurassic types. 

 Throughout the whole thickness the lithological character seems 

 to remain very similar, and it would be impossible to sharply define 

 any of the divisions which pass from one into the other quite gra- 

 dually. 



A very fair section of the Spiti shales is seen near the Sirkia 



encamping ground (fig. 11) to some ten miles 

 lower down the Sherik river, and on the road 

 to Dongpu in the province' Hundes of Tibet. About a mile south 

 of this camping ground, I again observed a small reversed fault, which 

 has thrown the rhaetic and lias beds against the Spiti shales ; they 

 dip about 35 (though locally much disturbed) to north-east. The 

 section through the older beds is much the same as I found it higher up 

 the river, namely, the bed exposed near the base, is a hard dark-grey 

 limestone with many white calcspar veins crossing and recrossing 

 it in every direction in which the shaly partings contain Brachiopods 

 of upper rhaetic or liassic type. On it follow limestones, very little* 

 if at all different from those underlying them ; on it rests a thin zone 

 of dark earthy and oolitic shales which yielded chiefly Belemnites, 

 overlaid by from 70 to 100 feet of a very hard light grey limestone with 

 reddish irregular blotches, which contains numerous fossils, very diffi- 

 cult to extract from the hard matrix. Chiefly Bivalves, amongst which 

 a smooth Gervillia is very conspicuous ; these upper limestone beds 

 belong evidently to the lias (Tagling series of Stoliczka). 



The Spiti shales overlie this conformably, beginning with a 

 characteristic contact bed of a conglomeratic breccia, made up of 

 fragments of liassic rocks. It suggests a partial break or a change of 

 coast line after the deposition of the liassic limestones, though the Spiti 

 shales rest apparently conformably bn the lias. Indeed such change 

 is also suggested by the sudden appearance of soft black earthy 

 shales after an uninterrupted series of limestones. 



( 127 ) 



