[schofield] rocky MOUNTAIN TRENCH 97 



near Vancouver. A graphical illustration of the above description is 

 shown in Figure 3. 



The post-Eocene faulting caused an interruption of the drainage 

 in the vicinity of the Big Bend so that the north-flowing portion of the 

 Fraser as well as that of the Nechako, both of which flowed into the 

 Peace, were diverted into the Rocky Mountain trench to become 

 part of the proto-Kootenay River. Subsequently in the late Tertiary, 

 the south-flowing portion of the Fraser eroded headwards and captured 

 the above-mentioned portion of the proto-Kootenay, thus forming 

 the "Big Bend" of the Fraser. 



Pleistocene and Recent History 



The history of the Pleistocene and recent drainage of British 

 Columbia has been recorded so well by Dawson that reference to 

 these periods will not be undertaken. The reader is referred to Daw- 

 son's paper read before this Society in 1889: "On the later physio- 

 graphical geology of the Rocky Mountain region in Canada with 

 special reference to changes in elevation and history of the Glacial 

 Period." 



S€C. IV. Sig. 7 



