NITRATE PROSPECTS IN THE AMARGOSA VALLEY. 



3. The material of the underlying stratified clays in its original 

 condition. 



The chemical data follow : 



Chemical analyses of materials containing nitrates. 



Two things are indicated by these analyses, first, that the signifi- 

 cant nitrate contents are in the underlying clays rather than in the 

 efflorescences and, second, that sodium chloride and nitrate are 

 associated, those samples in which nitrate is very low being nearly 

 pure sodium sulphate. 



THE ORIGIN OF THE NITRATE. 



The data now at hand are too meager to permit the formation of a 

 complete theory as to the origin of the materials. It seems probable, 

 however, that at times during the Tertiary period of variable lakes, 

 there existed single playas or marshes in which the conditions were 

 favorable for the life and growth of bacteria capable of producing 

 nitrates from animal matter or from the air. The clays of the playa 

 bottom became more or less impregnated with the nitrate so formed, 

 producing the material of the beds as found. The other salts asso- 

 ciated with the nitrate were probably supplied by mineral decay in 

 the usual way. 



THE VALUE OF THE DEPOSIT. 



The commercial value of the deposit is quite problematical. It 

 can be considered fairly certain that the surface material, either with 

 or without salt efflorescence, is worthless. 



