GEOLOGY OF ARCTIC AMERICA 69 



The question of interglacial periods in the Arctic lands demands 

 attention. In the glaciated regions south of the Arctic Circle there 

 is good proof of at least two advances of the ice sheets with a long and 

 mild interglacial time;^^ but in the Arctic sector no interglacial beds 

 have been disclosed. Great oscillations of climate are known to have 

 taken place during the Pleistocene in temperate latitudes; and it is 

 altogether likely that evidence of similar changes will be found north 

 of the Arctic Circle when carefully looked for. 



Surviving Ice Caps 



There is need, also, for a study of the still surviving ice caps. The 

 great ice cap of Greenland has been crossed by various expeditions, 

 and a good deal is known of its surface slopes and of its meteorology; 

 but as the nearest existing analogue of the Pleistocene ice sheets of 

 Europe and North America it still deserves and is receiving earnest 

 study.^^ Several problems arise in connection with it. Do cyclonic 

 storms ever displace for a time the anticyclone and pile up a heavy 

 snowfall, unlike conditions in Antarctica, where the ice sheet is thin 

 and apparently in process of dilapidation? 



Was the Greenland ice cap formed early in the Pleistocene and 

 has it survived ever since? Or is it the last of a series of ice sheets 

 beginning with the Cordilleran, going on to the Keewatin center and 

 then to the Labradorean, and finally developing in Greenland? We 

 know that it was once larger than it is now and covered nearly the 

 whole of the great island. Did this ice cap disappear in the inter- 

 glacial time, or was it merely diminished in area and thickness? 



Information in regard to these points may be difficult to obtain 

 but would be very welcome to the Pleistocene geologist. 



In northern Labrador there are among the Torngat Mountains 

 and tablelands some areas of stagnant ice, probably' remnants of former 

 ice caps; but only a few small active glaciers survive, and these are 

 of the cirque type and occur only near the coast where drifting snow 

 accumulates.^^ It is probable that the ice caps of Baffin, Bylot, 

 Devon,, and Ellesmere Islands include every stage between the tiny 

 snowdrift glaciers of the Torngats and the tremendous ice engine 

 of the Greenland cap. A comparative study of present-day glaciation 

 in the region would certainly give interesting results. 



One would expect that the highlands of northeastern Labrador, 



13 A. P. Coleman: Ice Ages, Recent and Ancient, New York, 1926, pp. 20-31. 



1* See C. F. Brooks: The Ice Sheet of Central Greenland: A Review of the Work of the Swiss 

 Greenland Expedition, Geogr. Rev., Vol. 13, 1923, pp. 445-433 (for the title of the expedition's report, 

 see, above, p. 55, footnote 6). 



Lauge Koch: Some New Features in the Physiography and Geologj' of Greenland, Journ. of 

 Geol., Vol. 31, 1923, pp. 42-65. 



15 A. P. Coleman: Northeastern Part of Labrador and New Quebec, Geol. Survey of Canada 

 Memoir 124, Ottawa, 192 1. 



