SOME PRE-C AM BRIAN LITERATURE OF NORTH AMERICA 579 



rocks which He unconformably beneath the Carboniferous. Daw- 

 son found that an unconformity separated them into two divisions. 

 The rocks beneath this unconformity he classed as pre-Cambrian 

 and those above as Cambrian. Daly classifies all the rocks uncon- 

 formably beneath the Carboniferous as pre-Cambrian, excepting a 

 part of the quartzite rocks immediately underlying the Carbonifer- 

 ous which he believes may be Cambrian. The unconformity which 

 Dawson believed separated the Cambrian from the pre-Cambrian 

 Daly places within the pre-Cambrian, and calls the rocks below 

 this unconformity pre-Beltian, and those above it Beltian, with the 

 reservation previously stated that a part of the upper portion may 

 be Cambrian. 



The pre-Beltian consists of the dominantly Sedimentary 

 Shuswap series, about 26,500 feet thick, which is intruded by 

 batholiths, dikes, and sills of granite. It includes limestones, 

 metargillites, mica-schists, paragneisses, green schists and green- 

 stones, the latter probably of extrusive origin although no definite 

 extrusive characteristics have been found. The Beltian is also 

 dominantly sedimentary, consisting from the base up of about 200 

 feet of arkose sandstone overlain by about 18,000 feet of argilla- 

 ceous rocks interbedded with Umestones and quartzites, the whole 

 constituting the Albert Canyon division. Above this is the 

 Glacier quartzite division about 25,000 feet thick, the upper part of 

 which, Daly believes, may be Cambrian, although no fossils have 

 been found. 



The strike of the pre-Cambrian rocks is nearly east and west or 

 practically at right angles to the Cordilleran folding. Normal 

 faulting in part contemporaneous with deposition is more evident 

 than folding, and the bedding is either near]}- horizontal or only 

 slightly incHned. From the fact that both the Shuswap and the 

 Beltian are dominantly schistose with their schistosity essentially 

 parallel with the slightly deformed bedding. Daly infers that 

 the schistosity has not resulted from tangential stress but from 

 the weight of the sediments and the action of thermal solu- 

 tions. While the pre-Cambrian rocks are only gently inclined, 

 the Carboniferous and Triassic rocks of this region are highly 

 folded. 



