GEOLOGY OF REGION 



241 



content similar to that of a soil from a limestone forma- 

 tion, should be regarded with greater suspicion than the 

 latter soil because of the possible recontamination from 





at 











'. - '. ' >"_ i***.* a;it* '.' - .- 





Fig. 



A Layer of Alkali Several Feet below the 



Surface. The Possibility of such a Layer Makes an 

 Analysis of the Soil Necessary before it can be 

 Properly Judged. 



the unlimited supply of salt in the country rock. A knowl- 

 edge of the geology of a region, therefore, is a valuable 

 supplement to other information in judging alkali land. 



