10 MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



With the Trias comes a small, though consistent, stratigraphical 

 break. The evidence for any trustworthy subdivision of the Trias 

 is wanting, or very doubtful. 



At the base of the Trias there is another stratigraphical break, 

 and it seems certain that all representatives of the great Carboni- 

 ferous, or Carbo-Permian epoch, so well developed in Kashmir and the 

 Salt-Range, are either completely absent in Hazara or are represented 

 by the unfossiliferous Infra-Trias limestone (but see p. 29). 



With the so-called Infra-Trias we enter on unfossiliferous rocks 

 of unknown age ; but a comparative study of other Indian regions 

 gives us a possible clue to the age of its lowest member (see p. 19 

 et seq.). 



Below the Infra-Trias is a great stratigraphical break with total 

 unconformability upon the great azoic Slate series beneath. 



The crystalline and metamorphic rocks exhibit a Himalayan 

 facies as regards the crystalline schists and intrusive sills of gneis- 

 sose-granite and the basic dyke rocks ; but the great thickness of 

 subaerial volcanic rocks of Palaeozoic age, exposed in Kashmir, are 

 not known in Hazara. 



The following details have sole reference to the petrology, normal 

 succession, lateral variation, age, and palaeontological position of the 

 formations and rock-masses in Hazara. I propose to begin with 

 the lowest known of the stratigraphical or historical rocks, that 

 is to say, the Slate series, and to work through the formations one by 

 one in ascending order. The crystalline and metamorphic rocks, 

 though connected with the historical rocks in a definite way, will be 

 treated separately as a distinct branch of the same subject, after the 

 normal unmetamorphosed series and groups have been described. 



Historical Rocks, 



(I) Slate series. 

 The oldest known rocks in Hazara consist of a great series of 

 thin-bedded, argillaceous, and slightly arenace- 

 ous deposits, which in the most typical parts of 

 the district are known in general terms as slates. Their dark and 

 ( «o ) 



