STRUCTURAL GEOLOGY AND THE FORM OF THE GROUND. 19 



mark the same great later or post-tertiary period of mountain-forming 

 activity, in which originated not only the remainder of the Salt Range 



chain, but also the Western Himalaya and the 

 Last disturbance. . 



Suleman and Afghan ranges. This is evident 



from the tilting of the higher tertiary beds on both sides of these trans- 

 Indus escarpments, hence the last disturbance must date from a period 

 later than that of the newest inclined beds. 1 



Whether the dislocations of the strata which possibly contributed 



Connection with paral- largely to the formation of the escarpments are 

 lei fractures. strictly synchronous with the elevation of the 



mountains, or were formed towards the close of the display of force that 

 has left its mark so strongly upon the country, it is not easy to decide ; 

 but the probability seems to be that while inseparably connected with 

 the general disturbance, the fractures, particularly if caused by strain 

 and accompanied by partial subsidence, took place after the formation of 

 the curves. 



Of earlier disturbances of the region, one which dates from post- 

 eocene times may be connected with the absence 



Early disturbances. 



of the great group of lower tertiary Murree sand- 

 stones and clays so largely developed in other parts of the Punjab. 

 To account for this, mere local cessation of deposition at this Murree 

 period might have been sufficient, but that with the missing beds in 

 some localities the eocene limestones have also disappeared entirely. 

 These, it is true, are by no means universally found in the sections of 

 the Upper Punjab, but the absence of both together is very suggestive 

 of a physical reason, such as local elevation of the sea bottom. And 

 further, where these limestones and the Murree beds are wanting, there is 



1 The high angle at which part of the Kalabagh mountain post-tertiary beds are 

 inclined (45° to 50") would be a reason for supposing the general elevation of the region 

 of later than post-tertiary date ; but elsewhere in the district conglomerates and sands, 

 evidently of recent accumulation, are found inclined at the same high angle (see p. 65) ; 

 hence if it be possible that detrital beds in the latter case were deposited at this angle, so 

 migbt they have also been in the post-tertiary instance specified. In this Kalabagh instance 

 subsidence might also have influenced the position of the beds. 



( 229 ) 



