Bulletin No. 213 
Series A, Economic Geology, 24 
DEPARTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 
CHARLES D. WALCOTT, Director 
CONTRIBUTIONS 
ECONOMIC GEOLOGY 
19 2 
S. F. EMMONS 
C. W. HAYES 
Greologists in. Charge 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1 9 3 
