17-t SUB-HIMALAYAN BOCKS OF N. W. INDIA. [CHAP. VI. 



formation of the mountain chain, we have seen such good evidence in 

 the Sub-Himalayan rocks. That pressure seems to involve the removal 

 of some positive sustaining force, such as M. de Beaumont's bosselle- 

 ment, or something still more vague and unknown. 



I will conclude by briefly enumerating the principal conclusions to 

 which we have been led by the study of the area, to the description of 

 which this memoir is specially devoted. 



The Himalayan mountain area was defined before the deposition of 

 the Subathu nummulitic rocks. 



Throughout all the succeeding Sub-Himalayan period, the same limit 

 of deposition has obtained. 



During the deposition of the upper group of this Sub-Himalayan 

 period, the very mountain streams were the same as now exist. 



The Krol-group — the youngest of the older rocks — though greatly 

 denuded, had undergone little or no contortion along the outer zone of 

 the mountain area, prior to the formation of the Subathu nummulitic 

 rocks. 



The special elevation of the Subathu group indicates that an upheaval, 

 coinciding in direction with that of the Himalayan area, took place (east 

 of the Sutlej,) before the deposition of the next succeeding group. 



That a phenomenon of a similar kind determined the separation of 

 the succeeding groups. 



That the contortion and fracture of the Sub-Himalayan rocks is a 

 reflex effect produced by the subsidence of the mountain-mass, the 

 upheavals of the same zone being probably an effect of the same 

 cause. 



