GEOLOGY OF THE PROVINCES OF BARAHONA AND AZUA. 



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ties are calcium, magnesium, and potassium chlorides and sodium and 

 calcium sulphates. Such salt can be used without purification for some 

 purposes, such as refrigeration, but it could not be exported for use as 

 table salt without refining. Much of the salt now sold for this purpose 

 contains more than 99 per cent of sodium chloride. It contains only very 

 small amounts of potassium. A salt less pure is hygroscopic and is there- 

 fore not so desirable, for a very small amount of calcium or magnesium 

 chloride in salt causes it to absorb moisture readily. The analyses indicate 

 that the deposits have no commercial value except as common salt — sodium 

 chloride. The water-soluble constituent is principally sodium chloride. 

 The remaining constituents were determined qualitatively, except the 

 potassium, which was determined quantitatively. 



Qualitative and quantitative analyses of water-soluble constituents of samples of salt from 



Cerros de Sal. 



[Analyses by E. T. Erickson.) 



a Salt incrustation on rock of arroyo below La Partilla. Stained green with oxidized copper. 

 6 Soil from shore of Laguna Rincon, near Cristobal, Barahona Province. 



The terms used in the above table signify approximately as follows: 



Trace = less than .05 per cent. 



Very small amount = less than 1 per cent. 



Small amount = over 1 per cent and less than 5 per cent. 



Fair amount = over 5 per cent and less than 15 per cent. 



Qualitative tests of the samples for bromine, iodine, boron, and lithium 

 showed inappreciable quantities. 



The amounts of potash in these samples are insignificant when compared 

 with the amounts in the salt mined at deposits in Europe. The potash 

 deposits of Upper Alsace average 18 per cent of K 2 0; the part mined 

 contains 20 to 22 per cent, and the principal bed is about 5 meters thick. 

 This bed is overlain and underlain by a great thickness of rock salt. The 



