2 SUB-HIMALAYAN ROCKS OF N. W. INDIA. [CHAP. I. 



which may appear at first sight unimportant, trifling, or irrelevant, feel- 

 ing, as I do, that such facts may afterwards supply valuable evidence, 

 when investigations have been extended over a wider range * 



In deciding on a plan for the extension of the Geological Survey 

 into North- Western Hindustan, there were two courses prominently 

 open for selection. Already the fossil fauna of the Sivalik hills, brought 

 to light by Cautley and Falconer, had created a deep and enduring 

 public interest in the geology of the southern slopes of the Himalayas ; 

 and, more recently, the valuable labors of D'Archiac and Haime in the 

 palaeontology of the Nummulitic strata, including those of Subathu, 

 had given additional attractions to the same regions. In opposition to 

 these strong inducements to begin with the Himalayas there was the 

 well ascertained fact that the original stratification of the formations 

 composing these mountains had been much complicated by disturbances. 

 Judging from this fact that insurmountable difficulties would present 

 themselves at every step in the attempt to elucidate the physical history 

 of the Himalayas, — and it will be seen in the following pages that this 

 surmise was well founded, — it was resolved that the country beyond the 

 great plains which stretch southwards from the base of the Himalayas 

 should be examined first. It was considered probable that the structure 

 and relations of the rocks composing this extensive and comparatively 

 plain tract of country were much more simple than in the mountain 

 regions, and it was hoped that thus some clue might be discovered to 

 the complicated geology of the latter. Accordingly I was deputed in 

 1856-57 to survey Bundelcund and parts of the adjacent country, and 

 the great Vindhyan formation, was then traced from Rewah, where it is 

 typically developed, into the country towards Gwalior. The result 

 of this work has been published in the form of a memoir in the 



* In order to elucidate my observations upon the obscure question of mountain formation, 

 I have given in an appendix a brief summary of the most prominent opinions with regard 

 to it. 



