72 



THE ROYAL SOCIETY OF CANADA 



Section! in Robson District, British Columbia 



The Geology of the Trench 



1. At the 49th parallel. — The geology of the trench in the vicinity 

 of the 49th parallel and at Bull River can best be expressed in parallel 

 columns showing the stratigraphy on each side of the trench. 



Purcell Range Rocky Mountain System 



Western flank Eastern flank. 



DiSCONFORMITY 



Elko formation 



Dolomitic limestone 



Middle Cambrian . 



90 feet 



Burton formation 

 Shales 



80 



Walcott, C. D., Smithsonian Misc. Coll., vol. 57, No. 12, 1913, p. 341. 



