92 SUB-HIMALAYAN ROCKS OF N. W. INDIA. [CHAP, III. 



the great specific difference of the fossils to be compatible with 

 contemporaneity.^ 



The subject I will now bring forward is of great theoretical interest, 

 Relation of Nalum and* as bearing upon the general problem of the struc- 

 groups. _^ e o £ ^q mountain region : it is, the relation 



of the Subathu group to the succeeding member of the Sub-Himalayan 

 series. Orographically the area of the Subathu group belongs to the 

 Lower Himalayan region, not to the characteristic Sub-Himalayan 

 zone. To the east of the Sutlej the inner boundary of the Nahun 

 Apparently a "rcat group is the most steady and most remarkable 

 fault-junction. feature that occurs : it bears in all the sections 



the appearance of a gigantic fault, and it is of the utmost importance 

 to obtain a true idea as to its real nature. In looking at the map 

 the feature perhaps most readily noticed is the partial extension of 

 the Subathu group as compared to that of the others. To the 

 practised eye a closer inspection will show, that on the north-west 

 this limitation is due to overlap by the younger rocks, while, to 

 the south-east, it is produced by a very different cause, namely, 



* In connection with these Punjab sections there is a suggestion to be noticed relating to 

 the Krol rocks as 'much as to the nummulitic group. In the Murree section I noticed one 

 new feature. In the nummulitic zone there occurs a considerable amount of clear blue limestone 

 not distinguishable from that of Mochipoora, and in which nummulites are easily detected. 

 The rocks just west of Tret bungalow are of this limestone ; and again at the place called 

 Clifden, near Murree, it is well seen. There would be nothing whatever forced in supposing 

 this to be only a local development of limestone among the true Subathu beds, for even 

 at Subathu we find occasionally bands of pure blue limestone among the clays. But there 

 seems to be a remote possibility of this limestone being fully identified with the great mass of 

 Mochipoora, and of Dundelee, and hence of the Krol ; in which case the deeply denuded 

 unconformability, which I have established between the Subathu beds and Krol group, would 

 prove to be only a break in the nummulitic period. However improbable such a result may 

 seem to be, I am induced to notice the fact in this connection, on account of the suggested 

 reference of the Lower Himalayan slates and limestones of Naini Tal to the nummulitic 

 period, as mentioned in page 88. Should such prove to be the case, the limestone of the 

 Salt-Range probably belongs to this lower nummulitic formation ; and under this arrange 

 ment the Salt-Range coal would correspond to the Infra-Krol carbonaceous deposits of the 

 Lower Himalaya. 



