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STRUCTURAL GEOLOGY OF NORTH AMERICA 



SHUSWAP TERRANE 



Fig. 17.14. Generalized distribution of major rock units of southern British Columbia. After 

 Smith and Stevenson, 1955. The Shuswap terrane has some Paleozoic and Belt outcrops and the 

 Belt terrane has some small patches of Paleozoic. All are invaded by great plutons, not shown, 



Range. The strata are, in part at least, marine; but the presence of plant 

 remains and other features indicates that the sea was shallow and that 

 possibly some parts of the assemblage may be nonmarine. In southern 

 British Columbia, various assemblages of sediments or of sedimentary and 

 volcanic strata are known, and others are believed to be of Jurassic age, 

 as in the Kootcnay Lake district where fossiliferous Jurassic beds rest on 

 Paleozoic strata. In general, the Jurassic beds appear to be as widely, or 

 even more widely, distributed than the Triassic; and as yet there is no 

 evidence of any interval of orogenic movements that separated the two 



except the Upper Cretaceous of Vancouver Island and the strata east of the Rocky Mountain 

 trench. 



periods. Thick assemblages of sediments and pyroclastics, as well as great 

 volumes of extrusive and intrusive volcanic strata, occur in northern Brit- 

 ish Columbia and southern Yukon and apparently correspond to the 

 Hazelton group in the south. For more detail, see Canadian Geological 

 Survey, Economic Geology Series, No. 1, 1957. 



Daly (1912) describes Triassic strata in northwestern Washington that 

 have a thickness between 3000 and 7000 feet. They are principally dark 

 gray to black argillite, in part bituminous, generally associated with bands 

 of gray to greenish gray sandstone and grit and in a few places with fine 



