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



partial relief; the evidence is equally strong for their infra-position to 

 the gneiss and schist series ; but such a supposition as this is still repug- 

 nant to our well-founded geological ideas. Here again what explains the 

 one will explain the other. The subject will come before us again. 



In the case of the great limestone bands to the east of the Chor 



we were able to trace into their vicinity the undoubted continuation 



of the Krol group, and thus to strengthen the independent evidence 



for the identity of the two. In attempting to do the same for the area of 



. , ., the lower Sutlei we encounter extra difficulty instead 



Limestone ridge north J J 



of ■ Erkl - of support. The Krol group is entirely cut out to the 



west of the Boj ; and with it disappears the rugged ridge which is elsewhere 

 so general a feature at the outer limits of the Lower Himalayan region. 

 Beyond Erki, sixteen miles to the north-north-west of the Boj, a fringing 

 rido-e of limestone appears again, occupying the same position in the 

 section as the ridge of the Krol rocks to the south-east ; and this 

 limestone is undoubtedly the same as that of the Sutlej valley. 



If the interruption of the limestone ridge between the Krol and Erki 

 were more complete than it is, we should have less hesitation in 

 supposing the rocks to be identical; for, in the intermediate ground 

 there is an apparent link which only adds to the puzzle. At and 

 south-east of the parade ground of Subathu, the nummulitic rocks 

 and their overlying red sandstones form the whole 

 ridge. To the north-west, grits and slates, some sub- 

 schistose, weather out along the point of the ridge. Among these thin- 

 bedded rocks a limestone soon makes its appearance, becoming gradually 

 more prominent as the ridge decreases, till at the Ghumber there is 

 nothino- else left but this band of limestone from fifty to one hundred feet 

 in thickness. Its lithological peculiarities can be well seen along the road- 

 side just north of Kukurhutti. It is remarkable for the very deceptive 

 appearance of organic forms that occur so generally in it. They are 



