SALINE Gl?Oirp. 83 



The regularity with which the red marl, salt, and g-ypsum arc 



overlaid by aqueous deposits, tog-ether with their 

 Solar evaporation. 



internal stratification so far as this is exhibited, 



are in favour of the salt having been produced by evaporation^ the 



theory most generally adopted. 



The absence in this vicinity of any known great volcanic vents. 

 Distance from any vol- either active or dormant, at the early period to 

 which the salt and gypsum belong, is not in favour 

 of a strong connection with volcanic causes, and yet the idea is strangely 

 associated with the fact that the only igneous rock of the whole Salt 

 Kange — one of apparently volcanic origin — occurs absolutely within the 

 saline series. The suggestion of high temperature indicated by the 

 semi-anhydrite, found not far from that porphyritic rock, bears upon 

 this point, as does also the association of dolerites and trachytes with 

 the salt-rocks of Hormuz in the Persian Gulf.* 



The internal structure of the salt beds and the numerous indications 



Possibly limited area ^f lenticular deposition, suggest limited areas of 



of accumulation. hcal accumulation on the same horizon ; perhaps 



of similar character to the salt-lakes Professor Ramsay has supposed 



to have existed during the Triassic period. f 



Some modern writers J suggest the existence of enormous salt- 

 producing causes, at extremely remote geological periods. This silurian 

 or pre-silurian Salt-Eange salt being among the most ancient deposits of 

 the mineral known, some trace of these causes of production might be 

 expected to show itself, but nothing has been detected to indicate a dif- 

 ferent origin from other salt-rock deposits. On the other hand, the 

 Trans-Indus salt, so much more recent, if laterally less extensive, has also 



* Mr. Blanford's paper in the Eecords of tlie Geological Survey of India, Vol. V, 

 part 2, p. 42. 



t Anniversary Address, 1864, Quar, Journ. Geol. Soc. Lond., Vol. XX, p. 47 j also 

 Quar. Journ. Geol. Soc. Lond., Vol. XXVIII, p. 160. 



J See Chemistry of the Primeval Earth, and subsequent correspondence by Dr. Sterry 

 Hunt-and Mr..David Forbes, Geol. Mag., Vol, IV, pp. 363, 365, 438, 439, and Vol. V. 



( 83 ) 



