Chap. II.] the Himalayan series. 53 



the Sutlej, in their normal position with respect to the more massive 

 siliceous limestone above. However, the contortion of these upper rocks 



Section from Simla in the Sutle J valle y is so great that in a rapid 

 across valley of Sutlej. smye ^ guch ^ m[ne hag been ^ ^ ^^ 



Himalayan area, one must indulge a little in inference when facts are 



deficient. Fig. 7 represents a conjectural section from Simla northward 



across the valley of the Sutlej. 



There is another mode of explanation which has many times occurred 



to me as plausible. In describing the Sub-Hima- 

 Second hypothesis, 



layan rocks, we will frequently meet with this 



same appearance of superposition of the older upon the younger strata ; 



in fact, it is the rule in all boundary sections, and under conditions when 



reverse faulting, or in some cases faulting of any kind is inadmissible. 



May not the explanation of those cases be applicable here also ? May 



not these upper beds of the unaltered series have been deposited against 



a steep cliff of the older rocks, or even in a deeply cut valley in them? 



Under subsequent lateral compression the newer rocks, and the upper 



strata yield most, and an overhanging junction might result. But 



this involves a very extensive unconformity of the two series of deposits, 



of which, in the present case, we have no direct evidence. If the 



question were only between the limestone group and the gneissose rocks 



there need be little hesitation in provisionally assuming this utter 



unconformity, but the apparent superposition is often almost as marked 



between the limestone and the Infra-Blini series, and we have already 



seen in the Simla section what we suppose to be the Krol group restino- 



upon the slate series with every appearance of true conformity. Whatever 



explanation we can give of the abnormal junction of the Krol group with 



the slates will also apply to that with the gneiss. 



The adoption of the opinion that these limestones of the lower 



Sutlej valley, and those in the Suinj and Neweli to the east of Chor, are 



not the Krol group, but much lower in the series, would only give very 



