and narrow lenses Some carbonaceous dust is also 

 usually present, and pyrite and garnet are common second- 

 ary minerals. In places, there is an alternation of dark 

 grey and light grey bands, the former representing the 

 more micaceous, and the latter, the more siliceous varieties. 

 The degree of crystallization also varies, the rocks ranging 

 from phyllites to fine grained gneisses. 



Approaching the granitic batholith there is no notable 

 increase in the crystallization, or in the quantity of 

 secondary minerals present, but aplitic dykes become 

 more common and in the last sections seen, the rocks 

 frequently have a striped appearance due to the intrusion 

 of small acid dykes along the bedding planes, and to the 

 silicification of layers of the schists. 



The Prince Rupert schists east of Prince Rupert, 

 have a uniform easterly dip of 30 to 70 degrees 

 towards the granitic batholith, and a N. N. W. strike 

 approximately parallel to the western edge of the batholith. 

 West of Prince Rupert, on Digby island, the structure 

 is more complicated and has not been worked out in 

 detail. The tilting and folding of the beds and the 

 crystallization of the sediments in part, at least, as first 

 explained by Spencer [6. p. 19] and confirmed by subsequent 

 observers, probably preceded the granitic invasion. 



The age of the schists, while not definitely known, 

 is probably upper Carboniferous, some confirmatory 

 fossil evidence having been obtained by F. E. and C. W. 

 Wright [8] in corresponding rocks farther to the north 

 in southeastern Alaska. 



Coast Range Batholithic Rocks. The belt of 

 granitoid batholithic rocks which follows the mainland 

 coast of British Columbia and Alaska continuously for 

 nearly 850 miles (1,368 km.) from Fraser river north to 

 latitude 6i° N, has a width where crossed by the Skeena 

 river, of 58 miles (93 km.) This long granitic mass, 

 formerly considered to be the product of a single linear 

 invasion, is really made up of a number of batholiths 

 separated in age by considerable time intervals. The 

 intrusions commenced in the Jurassic, and on the evidence 

 of bordering satellitic stocks, probably continued into 

 Lower Cretaceous. 



The rocks represented in the line of batholiths range 

 from acid granites to gabbros. The prevailing variety 



