PLEISTOCENE VULCAN ISM OF BRITISH COLUMBIA 267 



The age of this cone appears to correspond with that of Red 

 Mountain. Neither can be said to have originated as far back 

 as the first glacial period. In the tills, however, which represent 

 the end of that period in the Capilano Valley, near Vancouver, 

 there are blocks of the reddish andesitic lava which is characteristic 

 of this period of vulcanism. This locality lies south of Mount 

 Garibaldi, and could only be reached by ice of a general glaciation, 

 moving over the summits of the higher ridges. It is probable, 

 therefore, that Mount Garibaldi is of considerably earher date than 

 either of the smaller vents to the northward, and that the lava 

 erratics of the Capilano Valley may be referred to the early erup- 

 tions of Mount Garibaldi. This would also agree with the exten- 

 sively dissected condition of the Garibaldi cone as compared with 

 the others. The total time-range of the vulcanism would there- 

 fore extend from early Pleistocene through a considerable part of 

 the Recent, if we suppose the earliest recorded glaciation to have 

 been in fact the earliest of the Pleistocene ice-ages. In any event, 

 we must place the beginning of the vulcanism well back in the 

 Pleistocene. 



The nature of the lavas, which are reddish-brown andesites and 

 andesite-porphyries indicates a lithological relationship with the 

 Pleistocene volcanics of the Pacific coast states. The zone of 

 activity is thus extended from Mount Baker in a north-northwest 

 direction for about 100 miles, and into a quite new geological 

 province, that of the Coast Range batholith. 



