Chap. Ill] sub-himalayan series — subathu group. 91 



nummulitic clays, and in the more deeply cut sections below Tret, about 

 Shah Durrah, carbonaceous, sulphureous, gypseous, efflorescing shales are 

 exposed, I presume, representing the Infra-Krol band. 



The identification of the Subathu group, in its characteristic form, at 

 Compared with the suc ^ a distance, adds greatly to its importance, 

 ange ep0S1 s ' and it is of particular interest in this more north- 



erly locality, on account of its comparative proximity to the nummu- 

 litic rocks of the Salt-Range, and of the contrasting conditions of the two 

 deposits. There is no similarity between them as rock-groups ; and there 

 is no trace in the Salt-Range of the great thickness of hard sandstones 

 and red clays, which we have seen to be constant companions of, and to 

 be connected by interstratification with, the true nummulitic beds of 

 Subathu, and which are so largely developed in the Murree district. The 

 fact of the two thus disappearing together is an additional link between 

 them. In the Salt-Range the massive unconsolidated mammaliferous 

 clays and sands of the upper Sub-Himalayan groups rest upon a denuded 

 surface of the clear, highly fossiliferous, nummulitic limestone. The sim- 

 plest conjecture to form upon these imperfect data is, that the nummulitic 

 limestone of the Salt-Range is the open sea contemporary of the Subathu 

 group, and that the great clay and sand deposits which at first alternated 

 with, and finally covered up, the nummulitic deposits along the Sub- 

 Himalayan region, never reached so far as the Salt-Range. The com- 

 parison of the few fossils that have been described from the two deposits 

 partially bears out the conjecture just made. In the work of M.M. 

 D'Archiac and Haime there are forty-four species described from the 

 Salt-Range, and the same number from the Subathu beds ; not one 

 is common to the two localities, a fact throwing some doubt upon 

 the contemporaneity of the groups. In respect however of habitat 

 the species of Subathu are uniformly of shallow water forms as com- 

 pared with those of the Salt-Range. The great difference in the 

 nature of the sediments in the two localities leaves it possible for 



