S80 WYNNE: GEOLOGY OE THE SALT EANGE IN THE PUNJAB. 



The absence of igneous rocks, too, with the exception of the vol- 

 canic-looking varieties occurring in a few places 

 gneous roc s. ^^ ^^^ eastward, though unusual in such disturbed 



palseozoic rocks, may be very possibly connected with the continuously 

 tranquil deposition shown by the general parallel conformity of the 

 strata. 



From what has been already said, it will be seen that there is 

 considerable difficulty in conjecturing under what 

 ^^^ ' circumstances tlie salt-marl was accumulated. Por 



the stratified portion and its associated layers, however, estuarine or lacus- 

 trine conditions may have prevailed. The succeeding purple sandstone 

 group contains no organisms to indicate its orgin, which, nevertheless, 

 may have been marine. The next group contains a few marine (silurian) 

 fossils. The " magnesian arenaceous group " and the " speckled sand- 

 stone o-roup " may also have been deposited in sea water, subject to land 

 floods, bringing down earthy matter. The carboniferous group and 

 western portion of the trias are certainly marine, while the beds supposed 

 to form an eastern representative of tbe latter group may have been 

 deposited in an isolated tract of saline or of salt water. The Jurassic, 

 cretaceous, and nummulitic groups were also marine, or largely so, some 

 plant beds in the first and the leaf-bed at the base of the latter, together 

 with those bands in which coal or coaly shales predominate, being by 

 no means necessarily exceptions ; and the great mass of tertiary sand- 

 stones and clays have furnished nothing to contravene the supposition 

 that, notwithstanding their great thickness, they were deposited under 

 fresh or brackish water conditions. 



The. Salt Range rocks then form a continuous series, embracing 

 alternations of calcareous, earthy, and arenaceous 

 deposits, chiefly marine, but possibly in part of 

 fresh-water origin — a series (including the more recent beds) compris- 

 ing thirteen main divisions, of which nine are distinctly referable, each 

 to one of the thirteen principal formations known to geology ; and the 

 ages oi four are less accurately ascertained. Two of the latter are as 

 ( 280 ) 



