August-September 1922 



Vol. XXX, No. 



The Journal of Geolog 



Edited By 

 thomas c. chamberlin and rollin d. salisbury 



With the Active Collaboration of 



STUART WELLER 



Invertebrate Paleontology 



EDSON S. BASTIN 



Economic Geology 



ALBERT JOHANNSEN 



Petrology 



ROLLIN T. CHAMBERLIN 



Dynamic Geology 



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