ITS FKATIMU*:S AND INVESTIGATORS 69 



It was in this region also that the occurrence of contemporaneous vol- 

 canic materials as important constituents of the Mesozoic and Paleozoic 

 rocks of the Cordilleran belt was first recognized. Previous to the earlier 

 reports of the Canadian Geological Survey on British Columbia, the ex- 

 istence of such volcanic materials had been admitted onl}^ as regards 

 the Tertiary formations, in the western portion of the continent. 



Investigators 



The geological exploration of British Columbia was begun in LSTl by 

 Dr A. R. C. Selwyn, assisted by the late Mr James Richardson. Taking 

 all the circumstances into consideration, the report then made by 

 Dr Selwyn must, I think, be regarded as a remarkably valuable and im- 

 portant one. My own investigations in connection with the Geological 

 Survey began in 1875 and in 1887 extended to the Yukon district. 

 Work was carried on in the Cariboo district for some years under the 

 control of the late Mr Amos Bowman, and in later j^ears Messrs J. 

 McEvoy, R. G. McConnell, J. B. Tyrrell, R. W. Brock, and J. C. Gwillim 

 have also been in charge of parties in different parts of this Cordilleran 

 region of Canada. 



Physiographical Features 



It is not my intention, however, here to follow the development of our 

 knowledge of the region historicall}^ through its various stages, but rather 

 to enumerate the several formations now known to be represented, to 

 briefly describe each of them, and then to review the main outlines of 

 the geological evolution of this part of the continent in so far as it has 

 been made apparent. For this purpose a few words must first be devoted 

 to the existing physiographical features of the region. 



Pleistocene events and matters connected with the glaciation and later 

 superficial geology may be excluded from consideration, as these have 

 been treated at some length elsewhere."^ 



As compared with the Cordilleran region in the Western states, that of 

 British Columbia is much less diffuse and more strictly parallel with 

 the corresponding part of the Pacific coast. Its length is approximately 

 the same, but its width is usually about 400 miles only. The several 

 mountain systems are separated by narrower intervals, and, except in the 

 extreme north, may be more readily traced and defined. All the main 

 physical features trend in a north-nortliwest direction for about 1,100 

 miles, after which the mountain axes turn somewhat abruptly westward, 



* Trans. Koyal Soc. Can., vol. viii. Presidential address to Section IV. 



