CUAP. 10] 



ELECTRICAL METHODS 



661 



Table 65— Concluded 

 RESISTIVITIES OF IGNEOUS & METAMORPHIC ROCKS 



Table 66 

 RESISTIVITIES OF CONSOLIDATED SEDIMENTSi^ 



Rock 



Shales and Slates 

 Chattanooga 



shale (Dev.) 

 Shale & glacial 



drift 

 Nonesuch shale 



Shale 



Slate 



Clay (wet) 



Locality 



Cent. & south 

 Illinois 



Houghton 

 Co., Mich. 



W. Hancock, 

 Mich. 



Jugoslavia 



" Electrode spacing in four-terminal method, in feet. 



'^ Determined in the field. 



