72 GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



seems to be closely connected with the beds 

 Muschelkalk. 



above, which are grey, concretionary, generally 



very hard limestones, containing a purely Muschelkalk fauna. Sto- 

 liczka has correctly identified the horizon in Spiti and described 

 a number of fossils from it. This division may be looked upon as 

 the upper part of the lower trias ; the demarcation between it and 

 the succeeding strata is very slight, as regards the lithological char- 

 acter of the two divisions, but on the other hand, the next succeeding 

 division is well characterized by a peculiarly upper trias fauna. 



In the Spiti and the eastern sections (Dharma, Lissar, etc.), the 



upper trias forms one continuous limestone and 

 Upper trias. 



dolomite series, only parted by calcareous shales 



whilst in the Niti and Milam sections great thicknesses of friable 



shales come in near the upper half of the series, which have yielded 



fragments of vegetable matter. Generally speaking, the lower half of 



the upper trias is developed mostly as a series of very dark, almost 



black, hard limestones with partings of shales ; this sub-division may 



be seen in all triassic sections of the Himalayas, and forms one of the 



most characteristic horizons ; Daonella sp. and true upper trias Ce- 



phalopods (Hallstadt types) are found in these lower beds. 



The upper beds show more variation. Chiefly shaly in the Niti 

 and Milam areas, they are represented by strong limestones in Spiti 

 and in Dharma, Fossils are rarer in this horizon, which is also often 

 inaccessible, as it generally forms precipitous cliffs. But enough of 

 fossil remains have been found in beds of this division to allow local 

 identification of the horizon where seen. 



Neither in this grand series of trias beds, nor in the succeeding 

 rhaetic has any unconformity been detected, but rather a gradual 

 passage from one into the other sub-division may be observed. 



7. Rh&tic and Lias, 

 From the north-western corner of the ground here reported on, 



namely, the Spiti valley, to the frontier of Nepal, 

 Rhaehc and lias. J ' r J 



I found the upper trias regularly and conform- 

 ably overlaid by great thicknesses of limestones and dolomites, of 

 ( 72 ) 



