70 POLAR PROBLEMS 



rising 4000 or 5000 feet above the open Atlantic, with an average 

 temperature of 27.1° F. and a very low maximum in the two summer 

 months (44.6° in July and 46.9° in August at sea level), would be 

 heavily glaciated as compared with Ellesmere Island, which is screened 

 from moisture-bearing winds by Greenland and the floe ice of Baffin 

 Bay; but the reverse is the case. 



Problems in Structural Geology 



Finally there are interesting but difficult problems to be solved 

 in regard to the origin and relationship of the polar lands and seas. 



Why is it that the north pole is situated in a fairly deep ocean 

 almost completely surrounded by the greatest land areas of the 

 globe, while the south pole is on a lofty tableland in the heart of a 

 continent which is surrounded by the world's greatest oceans? The 

 two polar regions are in exact contrast with each other. 



Are the three northern Archean shields the blunted corners of an 

 indistinct tetrahedron, and is the Antarctic Continent the fourth, im- 

 plying an ancient collapse of the earth's primal crust; or are these 

 contrasts accidental? 



The structural geologist has reason to ponder over these polar 

 contrasts, which, perhaps, will never be satisfactorily accounted for. 



The extraordinary arrangements of land and sea in the European 

 and North American sectors of the Arctic Regions have often aroused 

 the interest of geologists and geographers, and it has been pointed 

 out that the land areas, especially Labrador, the Archipelago, and 

 Greenland, if suitably shifted, would make a compact continental 

 territory, fitting together like the blocks of a puzzle. Is this only 

 apparent, or were these lands once continuous and have they since 

 then drifted apart? Very interesting theories have been proposed 

 to account for these relations. 



Taylor in 1909 suggested that the polar lands were once parts of 

 North America, but that the continent began to drift toward the 

 southwest, thrusting up the Cordillera on its way and leaving behind 

 blocks of the crust at various distances. ^^ 



A few years later Wegener proposed an elaborate theory of the 

 drift of continents, his starting point being an apparent shift of longi- 

 tude within historic times in Greenland. His speculations cover all 

 the continents and are supported by attempted explanations of glacia- 

 tion in Permo-Carboniferous and Pleistocene times. ^^ From the 

 point of view of the glacialist his conclusions are unacceptable; but 



16 F. B. Taylor: Bearing of the Tertiary Mountain Belt on the Origin of the Earth's Plan, Bull. 

 Geol. Soc. of Amer., Vol. 21, 1910, pp. 179-226. 



1' Alfred Wegener: Die Entstehung der Kontinente und Ozeane, 3rd edit., Brunswick, 1922 

 (ist edit., 1915; first publication in idem: Die Entstehung der Kontinente, Petermanns Mitt., Vol. 

 58, Part I, 1912, pp. 185-195, 253-256, and 30S-309). 



