THE GLACIAL PERIOD AND THE EARTH-MOVEMENT HYPOTHESIS. 'lot 



Ave have been considering can be accounted for by movements 

 of the earth's crust — a view which has recently received con- 

 siderable support, more especially in America. I need hardly 

 say that the view in question is not a novelty. Many years 

 ago, while our knowledge of Pleistocene phenomena was 

 somewhat rudimentary, it was usual to infer that glaciation 

 had been induced by elevation of the land. This did not 

 seem an unreasonable conclusion, for above our heads, at a 

 less or greater elevation, according to latitude, an Arctic 

 climate prevails. One could not doubt, therefore, that if a 

 land-surface were only sufficiently uplifted it would reach 

 the snow-line, and become more or less extensively glaciated. 

 But with the increase of our knowledge of Pleistocene and 

 postglacial conditions, such a ready interpretation failed to 

 satisfy, although not a few geologists have continued to 

 defend the " earth-movement hypothesis," as accounting 

 fairly well for the phenomena of the glacial period. By these 

 staunch believers in the adequacy of that view, it has been 

 pointed out that elevation might not only lift lands into the 

 region of eternal snow, but, by converting large areas of the 

 sea-bed into land, would greatly modify the direction of ocean- 

 currents, and thus influence the climate. What might not 

 be expected to happen were the Gulf Stream to be excluded 

 from northern regions ? What would be the fate of the 

 temperate latitudes of North America and Europe were that 

 genial ocean-river to be deflected into the Pacific across a 

 submerged Isthmus of Panama? The possibility of such 

 changes having supervened in Pleistocene times has often 

 been present to my mind, but I long ago came to the con- 

 clusion that they could not account for the facts. Moreover, 

 I have never been able to meet with any evidence in favour 

 of the postulated " earth-movements." Having carefully 

 studied all that has been advanced of late years in support of 

 the hypothesis in question I find myself more than ever con- 

 strained to oppose it, not only because it is grounded on no 

 basis of fact, but because it altogether fails to explain the 

 conditions that obtained in Pleistocene and postglacial 

 times. 



There are various forms in which the hypothesis has 

 appeared, and these I shall now consider seriatim, and with 

 such brevity as may be. It has been maintained, for example, 

 that at the advent of the glacial period vast areas of 

 Northern and North- Western Europe, together with enormous 

 regions in the corresponding latitudes of North America, 



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