30 SUB-HIMALAYAN ROCKS OF N. W. INDIA. [CHAP. II. 



close by ; there is, moreover, the possibility in this spot of its being a rem- 

 nant of the nummulitic rocks caught in a contortion of the slates ; but I 

 could not discover any organic forms in it. The beds to which I will apply 

 the term Infra-Krol group may be from 1,000 to 2,000 feet in thickness. 

 The description I have given of the Infra-Krol beds would answer 

 o-enerally for the entire series of the unmetamorphic rocks below the 

 Krol group. Although the base to this series of strata is not discoverable 

 in this region, we find in them here a well denned horizon, a band of 

 rocks that is very peculiar and characteristic, and 

 which can be traced without any doubt to great dis- 

 tances, — a remarkable circumstance when we consider that their united 

 thickness is usually inconsiderable. This band promises to be of special 

 utility in identifying the rocks in the interior with those of the outer 

 parts of the Lower Himalayan region. The principal rock of this little 

 group is a pure limestone, very dense, sometimes 

 compact, sometimes sub-crystalline; its commonest 

 colour is pale pink, but often blue and greenish yellow ; it occurs in 

 thin, well-defined layers, but these are often agglomerated together into 

 one mass, the beds showing only as bands in this mass. From fifteen to 

 twenty feet is the pretty constant thickness of the whole. The limestone 

 by itself would be far from a satisfactory guide in the identification 

 of disturbed strata, where it is sometimes brought into proximity 

 with other similar rocks, such as those of the lower Krol beds, with 

 which it might readily be confounded. It has, however, a constant 

 companion more peculiar than itself, and the two combined fur- 

 nish an unmistakeable clue. This other rock is a kind of conglo- 

 merate. It occurs, I believe, below the limestone, though in the 

 many inverted contortions it often appears above. The base of this 



conglomerate is a fine, gritty slate, of a dull 

 Conglomerate. . 



green, or blue colour, m tact altogether like 



the thin-bedded rocks in the midst of which it occurs. Through 



