October-November 1922 Vol. XXX, No. 7 



The Journal of Geology 



Edited By 



thomas c. chamberlin 



With the Active Collaboration of 



ROLLIN T. CHAMBERLIN, Managing Editor 

 Dynamic Geology 

 STUART WELLER ■ ALBERT JOHANNSEN 



Invertebrate Paleontology Petrology 



ED SON S. BASTIN J HARLEN BRETZ 



■ Economic Geology Stratigraphic Geology 



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