4 



T<JPOGEArHY or THE 



The causes of such present diffei-ences of height are : the lieight to which the rocks 

 have been raised to begin with ; the leiigth of time that they have been wearing away, 

 and the general ease with which they wear away, which depends on their general 

 hardness, firmness, solubility and permeability. The final result of the wearing away 

 that is going on all over the land is, of course, to bring everything to a dead level, 

 and that the level of the sea. It might, therefore, be that land as high as the Ivoh- 

 istan once stood south of the Salt Range, and has, in the course of many ages, been 

 worn down to a low, flat plain ; as in the ccnirse of time the Kohistan must be, if it 

 should never be pushed upward again. But the low land south of the Salt Range, 

 is still high enough above the sea to show by unequal wearing away, harder libs of 

 rock, if it had them ; and it would seem to be pretty uniformly soft to some depth, as 

 if not long enough deposited to become very hard. It is probal^le, therefore, that since 

 the deposit of its present upper surface, it has never been raised so high as the Kohis- 

 tan, though this surface may rest upon a floor of much older rocks below, that nvAj 

 be the i-emnant of land as high as the Kohistan. 



The whole of the Kohistan, however, seems to have been raised about the same 

 time and to about the same height ; and its diiferences of level come in a great mea- 

 sure from the I'elative ease with which its rocks have been worn away, chiefly from 

 their relative hardness. But the table land has been in general wearing away for a 

 much less time than the mountain land, liecause it is made up of newer rocks that 

 were formed in the bed of what was perhaps a great lake in the older rocks that make 

 up the mountains. The newer rocks, then, take the place of a great hollow in softer 

 rocks of the older formation, a hollow that would have been woi'u still deejjer but for 

 the protection that has been afforded by the covering. 



This consideration enables some conclusions to be drawn as to the geology from the 

 mere topography. The Salt Range is formed chiefly of a thick lime rock (the num- 

 miilitic) and the softer rocks that it covers ; and the Choor Hill Range consists of a 

 similar probably the same lime rock ; and Khairee Moorut most likely of the same ; 

 in short, all the high mountain land of the region seems to be caused l^y the presence 

 of this thick lime rock, and it is probable that wherever it once rose above the present 

 level of the country it has left hills or mountains to mark its place. ]^ow, the dip on 

 the northern side of the Salt Range is northerly, and it is ]3retty certain therefore that 

 the southern dip of the Choor Hills must be southerly ; for, if this were northerly, 

 the lime rock must have risen to the surface somewhere between the two ranges, and 

 have left a ridge of rocks dipping southerly. Khairee Moorut is too short to re])re- 

 sent so long a ridge as this must have been, and is probably a small saddle of the 

 lime rock rising above the table land. The rocks, then, south of the Choor Hills as . 



