PHYSICAL FEATURES. 9 



fossils. The absence of organisms, so far as yet discovered, in trie sandstone 

 which here forms the principal member of the group, of course leaves its 

 age an open question, and some part, if not the whole, might as well be 

 cretaceous, as of any other immediately older or newer period. 



Early allusions to the Kalabagh portion of the district will be found 



in the writings of Elphinstone, Burnes, Munshi 

 Earlier observers. 



Mohun Lai, and Dr. Jameson. 1 These refer chiefly 



to the salt, coal, alum, and gold of the district. The last-named writer 



has arrived at a correct conclusion as to the value of the coal; although his 



classification of the rocks upon which his opinion is based has been found 



inapplicable. 3 



Physical eeatukes. 



Different opinions have been recorded as to where the true westerly 

 extension of the Salt Range proper lies; most of the early writers 

 haying supposed that the occurrence of rock-salt in the hills of the 

 Kohat district indicated the continuation of the range towards the 

 Safed Koh mountains in Afghanistan. In the Geological Survey 

 Memoir upon the Salt Range I have adopted the natural view that this 

 escarpment, both orographically and geologically, has its continuation 

 more to the southward, in the ranges bordering the Indus plains from 

 Kalabagh on that river to the British frontier (previous to 1879) 

 beyond the Bam-darra pass 3 northward from Tank. 



This portion of the northern wall of the Indian desert forms a 

 sigmoid curve lying between the points just named, for the most 



1 Elphinstone's Caubul, visited in 1808, Lond. 1815. Burnes, Sir A. : A Memoir : Geol. 

 Soc, Lond., Proc. Vol. II, and Jl. As. Soc, Bengal Vol. XII, p. 564. Mohun Lai : Jl. As. 

 Soc, Bengal, Vol. VII, p. 25. Jameson, Jl. As. Soc, Bengal, Vol. IX and XII. 



2 See introductory chapter, Salt Range Memoir, Mem. Geol. Surv. India, Vol. XIV. 



In which travelling is unsafe without an armed escort, though daily patrolled, and 

 protected by a fort at its south exit and a chain of towers along the line of road " — 

 Thorium's Banu, or, Our Afghan Frontier. During my inspection of this region in January 

 1879 the country was unusually disturbed, the town of Tank was raided and burned, and 

 other frontier posts were attacked by the hill tribes. 



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