128 
DiENEB : TRIAS OF THE HIMALAYAS. 
In the carnic stage two ammonite faunae can be distinguished, an 
upper with Tropiies suhhuVatus, and a lower one with Joannites cymhi- 
jorniis. Tlie Tropites fauna has not yet been found in Painkhanda and 
Johar. 
4. The noric deposits are, in their lower and middle divisions, richer 
in limestones and contain more natural rock groups in Spiti than in 
Painkhanda and Johar. They are divided into throe groups of 
beds : — 
Quartzite series. 
Brachiopod beds. 
Cephalopod beds. 
Locally the cephalopod beds are very rich in fossils in Johar 
(Bambanag clif!). But these beds (Halorites limestone) form no such 
constant stratigraphical horizon as the Muschelkalk. 
The lower noric beds of Byans show peculiar features, being made up 
of black shales of great thickness, which are wanting in the other 
districts known. 
Everywhere in the Himalayas the upper noric beds as far as we 
know consist of thick limestones and pass through beds of doubtful 
age into limestones of middle Jurassic age, which are overlain by the 
Upper Jurassic Spiti shales. From Spiti to Byans throughout the Meso- 
zoic belt of the Himalayas a ferruginous oolitic layer (Sulcacutus beds) 
occurs at the base of the Spiti shales and constitutes a very constant 
horizon (Kelloway) in the Mesozoic deposits of the Himalayas. 
The following table shows the relative thickness of the beds between 
the Productus shales and Spiti shales. It illustrates the remarkable 
decrease in thickness from north-west to south-east. 
The second table gives a classification of the Triassic series of Spiti, 
Painkhanda, Johar and Byans. This table shows clearly that more 
detailed researches will have to be carried out before we can correlate 
the Trias of Byans in any detail with that of the other two districts. 
The Trias of Kashmir is so litt'e known, that not even a rough outline 
of the stratigraphical sequence can be given. 
( 329 ) 
