Chap. II.] the Himalayan series. 73 



obtained from the metamorphic zone of the Dhaoladhar, do not exhibit 

 the phenomenon of cleavage in an indisputable manner : the rock in 

 question, it is true, is perfectly fissile ; but more fine-grained argillaceous 

 rocks interstratified with it exhibit no such tendency, as should be 

 expected in the case of a true system of cleavage. Moreover, the slate 

 itself seems to me to suggest the opinion that it is due to an excep- 

 tional form of foliation : it is a very fine siliceous rock, showing a de- 

 licate micaceous glaze on the surfaces along which it splits. These 

 planes moreover coincide with that of bedding. 



The discussion of the structural features of the Himalayan rocks, 



described in the foregoing pages, cannot be profitably undertaken until 



after we have examined the evidence regarding the Sub-Himalayan rocks. 



It is however already manifest how very limited and hypothetical any 



general argument must be until more is known of these older rocks, until 



some connection be established between them and the rocks of the central 



mountain regions. The Krol group has the strongest claim for interest, 



and offers at the same time the most hopeful pros- 

 Probable connection, 

 through Chamba, of the pect of discovery. A similarity has more than once 

 rocks on the north and 



south of the snowy been noticed between the slates of the Lower 



range. 



Himalaya, and the so-called azoic slates which 

 underlie the palaeozoic strata on the northern side of the snowy range ; 

 and the identity of the two has been surmised from this similarity. 

 It is something gained, however small, to be able to point out a fair pros- 

 pect of settling this question independently of fossil evidence. In the 

 hills immediately across the Ravee north of Dalhousie, the limestones and 

 slates on the south of the Dhaoladhar must come into contact with the 

 rocks of the Chamba valley, and there can scarcely be much difficulty 

 in discovering their relation to each other. I think, moreover, there is 

 much probability that the Chamba slates can be traced continuously 

 into connection with the unmetamorphic rocks of the Thibetan regions. 



K 



