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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [April 4, 



Fig. 5. 

 Beds of Rock Salt in Red Sandstone. 





Nor is it an easy matter to account for its occurrence, for not only is 

 it in a very elevated position, but the basins themselves are too isolated 

 and of too limited an extent, to allow us to attribute the formation of 

 the salt to the evaporation of the water of the ancient sea, on the 

 elevation of these rocks above the surface. A more probable solution 

 is, that these basins became the receptacles of salt springs which 

 flowed into them from the surrounding hills, in which the saline 

 matter may have been chemically produced by the effect of gases 

 entering the red sandstone in consequence of igneous or volcanic 

 agency. Not being a chemist, I throw out this suggestion with much 

 hesitation, but I cannot account for the pheenomena in any other way. 

 May we not imagine that muriatic vapours, coming in contact with 

 the soda contained in the felspathic elements of the marls, would 

 enter into combination with that basis and produce the requisite saline 

 matter 1 I must also observe, that wherever I have had an opportunity 

 of examining the analyses of natural saline springs, T have invariably 

 found that the chlorine or muriatic acid enters into combination mth 

 the soda, but not with the potass even when it is present. Thus, 

 whatever may be the opinion of chemists as to the greater affinity of 

 the chlorine for potash than for soda, it would appear that in the 

 great laboratory of nature such is not the case. 



The other principal element of this formation consists of a yellow- 

 ish sandy marl containing numerous masses and crystals of selenite, 

 sometimes passing into distinct beds of sands and clays equally full 

 of similar small crystals. Mr. Ainsworth describes this formation 

 as constituting very extensive uplands, and evidently saw it deve- 

 loped on a larger scale than I did. In the neighbourhood of Vizier 

 Keupri it forms the low undulating hills of the plain, which rest against 

 the older semicrystalline limestone. The low hills which surround 

 the plain of Tchorum also consist of it, containing masses of cal- 

 careous marl besides the crystals of selenite. I nowhere had an op- 

 portmiity of discovering any fossils in this formation. 



It also occurs to the west of the elevated and vertical ridge of red 

 sandstone west of Soungourli, where it forms low hills, horizontally 

 stratified, on the left bank of the Delhiji Su. Again, to the south-west 

 of Sevrihissar, after entering the great horizontal formation of Central 

 Anatolia, beds of crystalline gypsum and selenite crop out in the hills 



