16 THE ROYAL SOCIETY OF CANADA 



pointed out by Burwash,' there is a transition upwards from the till to 

 the stratified clays which overlie it, and these clays, although they 

 contain no marine fossils in this region are, because of their position, 

 probably marine. The amount of depression of the land relatively to 

 sea-level during this period is not definitely known but as evidenced 

 by the clays it was at least 200 feet and probably higher. The 

 occurrence of stratified clays overlain by till at high altitudes — up to 

 1,200 feet above the sea — in the Capilano valley tributary to Burrard 

 Inlet led Burwash- to conclude that the sea stood about 1,300 feet 

 higher than at present, but it is possible that the clays in this \'alley 

 and the sands over 200 feet in thickness, overlain by a few feet of 

 till which form the seaward part of Point Grey, west of Vancouver, 

 belong to a later, probably local, period of glaciation; for they are 

 unweathered, whereas the older clays are in places weathered, and it 

 is improbable that stratified clays would be left in a mountain valley 

 like the Capilano, following an extensive advance of the glaciers. 

 This occurrence of the stratified clays at such high levels is not easily 

 explained. They are possibly marine but the absence of other 

 evidence of submergence to this height does not favour this view. 



The deposition of the Admiralty sediments was followed by uplift 

 of the land and dissection of the drift deposits. Bretz'' holds that in 

 Puget Sound region the land stood about 1,000 feet higher than at 

 present -and that extensive valleys in the drift deposits were formed 

 during this period of erosion. Burw'ash* holds that in the Vancouver 

 region there is nothing that would necessitate a level much higher 

 than at present, unless ice erosion be neglected. Erosion of the drift 

 deposits took place during this period or at some time previous to the 

 latest deposits of till, for the valley occupied by the Fraser at New- 

 Westminster is cut in drift deposits and was formed in part at least 

 prior to the last advance of the ice, and the upland area of Point 

 Roberts composed largely of stratified sands and silts overlain by 

 till can not be a remnant of the late glacial delta for it is separated 

 from the mainland by the Recent delta deposits. It is probably a 

 remannt of a more extensive mass of sediments eroded by streams 

 during a period of retreat of the ice-sheet or by the ice-sheet again 

 advancing. In the upper part of the Nicomekl-Serpentine valley, 

 cut in drift deposits, borings have shown that the post-glacial clays 



1 Ibid., p. 85. 



2 Ibid., p. 85. 



3 Ibid., p. 237. 

 Mbid., p. 91. 



