PLEISTOCENE SEA-LEVEL 165 



pelled there to yield up their load of rock waste. We 

 know, from the extent of Pleistocene erosion in this dis- 

 trict, that the burden of rock waste was large, and wher- 

 ever the moraines were built they made an important de- 

 posit. If the Pleistocene base-level had been the same as 

 the present I should expect to find that deposit as a con- 

 tinuous bar, or string of linear islands, along the outer 

 coast of the Alexander Archipelago and at various points 

 farther south, but no such features have been described, 

 and the coast seems to have an entirely different character. 

 This consideration, though connected at present with only 

 negative evidence, distinctly favors the theory that the sea- 

 level associated with the greatest Pleistocene ice floods 

 was considerably below the modern sea surface. 



There is some evidence, on the other hand, of a com- 

 paratively high sea plane after the glacial maximum. 

 Dawson describes an extensive marine deposit, reaching 

 a height of 200 feet, on the east side of Graham Island, the 

 most northerly of the Queen Charlotte group, and infers 

 from its relations that it was contemporaneous with a 

 development of local glaciers. 1 At Nanaimo, on the 

 inner coast of Vancouver Island, he found shell-bearing 

 marine clays, resting on glaciated rocks, at a height of 70 

 feet above the sea. 2 In Gastineau Channel is a narrow 

 shore terrace at a height of 200 feet, and in an associated 

 clay Ball found marine shells. At two, at least, of the 

 localities the shells are of species indicating cold water, 

 and each locality is on the border of a sound or channel 

 which would be filled with icebergs by a moderate devel- 

 opment of glaciers. If the phenomena all belong to the 

 same chapter of Pleistocene history, they record an 

 episode similar to that of the Champlain clays of the At- 

 lantic seaboard. 



1 Quart. Jour. Geol. Soc. London, vol. xxxvn, p. 281, 1881. 

 a Quart. Jour. Geol. Soc. London, vol. xxxvn, p. 279, 1881. 



