Section- IV, 1921 [9] Trans. R.S.C. 



Pleistocene Oscillations of Sea-level in the Vancouver Region, British 



Columbia 



By W. A. Johnston, M.A., B.Sc. 



Presented by R. A. A. JohnstoxV, F. R.S.C. 



(Read May Meeting, 1921) 



Introduction 



The occurrence in the \^ancouver region, British Columbia, of 

 two Pleistocene boulder clays, separated by stratified sands and 

 clays, has long been known and has beendescribed by several geologists. 

 It was referred to by G. M. Dawson, who stated- that it was doubtful 

 whether the two boulder clays corresponded to the two periods of 

 glaciation, evidences of which he had found in the interior of British 

 Columbia, but that there may have been several climatic oscillations 

 during the Pleistocene. O. E. LeRoy, who examined the area in 1907, 

 describes briefly^ the Pleistocene deposits and states that the stratified 

 deposits overlain by till were formed by sub-glacial streams and also 

 by streams issuing from the front of the glacier at a period of recession, 

 but failed to find sufficient evidence to indicate an interglacial period. 

 This view is apparently also held by R. A. Daly"*, who examined the 

 area along the International boundary and by C. Camsell.^ In a 

 report*^ published in 1918 E. M. J. Burwash describes somewhat fully 

 the Pleistocene deposits of the area and gives evidence to show that 

 during the Pleistocene there was at least one interglacial period of long 

 duration. There is, therefore, a difference of opinion as to whether 

 extensive retreats of the ice-sheet took place in this region during 

 Pleistocene time, but there is no doubt that at least one retreat and 

 readvance of the ice-sheet occurred, the only point in dispute being 

 the extent of the retreat and its significance as indicating an inter- 

 glacial period. This question is not here, considered but attention 



^ Published by permission of the Director, Geo!. Surv. Can. 



2 Geol. Surv. Canada, Ann. Rep. Vol. VII, 1894, p. 253B. 



' Geol. Surv. Canada, Publication 99G, 1908, p. 27. Preliminary Report on a 

 portion of the main coast of British Columbia and adjacent islands, included in the 

 New Westminster and Nanaimo Districts. 



^ Geol. Surv. Canada, Memoir No. 38, Part 2, p. 596. 



6 Geol. Surv. Canada, Guide Book No. 18, Part 11, 1913, p. 272. 



® The Geology of Vancouver and Vicinity, The Univ. of Chicago Press, 1918. 



