October 30, 1922. 
Canada 
Geological Survey 
Bulletin No. 35 
GEOLOGICAL SERIES, No. 42 
RELATIONSHIP OF THE PRECAMBRIAN ( BELTIAN ) TER- 
RAIN TO THE LOWER CAMBRIAN STRATA OF 
SOUTHEASTERN BRITISH COLUMBIA 
By S. J. Schofield 
INTRODUCTION 
Rocks containing the Olenellus fauna were discovered near Cran- 
brook, B.C., by Col. C. H. Pollen, of Cranbrook, at the opportune moment 
when further work on the Beltian rocks of southeastern British Columbia 
was being planned by the Geological Survey. In April, 1921, Col. Pollen 
forwarded some specimens representing the Olenellus fauna to the Univer- 
sity of British Columbia, Vancouver, B.C., and the place of discovery 
near Cranbrook served as a starting place for the field work of the Geological 
Survey, under the writer, which commenced in May of the same year. In 
the course of this field work efficient help was given by J. F. Walker of the 
University of British Columbia. 
GENERAL STATEMENT OF THE PROBLEM 
The relationship of the Cambrian to the Precambrian (Beltian) in 
southeastern British Columbia hinges upon the presence of an unconformity 
between these rock groups. Walcott includes in the Precambrian (Beltian) 
the strata which occur between the general unconformity that marks the 
base of the Cambrian, whether Lower, Middle, or Upper Cambrian and 
another unconformity at the top of the basement complex, which he 
classified as Archaean. In places the Cambrian rests with apparent con- 
formity on the Beltian, but Walcott holds that a regional study proves- 
the existence of a stratigraphical and time break between the known 
Beltian rocks and the Cambrian sediments of the North American conti- 
nent. Dawson 1 held that complete stratigraphical conformity existed 
between the Cambrian and the Beltian down to the great unconformity 
which separates the Beltian from the basement complex. Daly 2 uses the 
term Belt-terrain to include all the Cordilleran strata which lie conform- 
ably below the Olenellus zone as well as the rocks which are contemporane- 
ous with those strata though not in proved conformity with the Olenellus 
zone. He holds that no unconformity exists between the base of the 
Beltian and the Cambrian. 
1 Dawson, G. M., Bull. Geol. Soc. Am., vol. 2, 1891, p. 173. 
2 Daly, R. A., Geol. Surv., Can., Mem. 68, 1915, p. 58. 
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