22 THE ICE AGE IN CANADA. 



active and voluminous of American glacialists,* adduces a 

 long array of citations from Geikie, Woeickkoff', Winchell, 

 Gilbert, Andrews, Wright, Mackintosh, Logan, Spencer 

 and others on facts showing the recency of the glacial 

 age, which he holds could not have been more remote 

 from our time than from 7,000 to 10,000 years. He 

 further concludes, from the observations of Dr. G. M. 

 Dawson and others, that " the cause of the glacial period 

 was great uplifts of the glaciated areas," accompanied and 

 followed by great and unequal subsidence ; and he brings 

 evidence to show that the passage of the equatorial 

 current into the Pacific, in consequence of the subsidence 

 of Central America, diverted the warm waters of the 

 Gulf Stream from the Atlantic. Claypole, in a review of 

 the Astronomical Theory ,f adduces a great number of 

 facts in evidence of the recency of the glacial period and 

 of its origin from terrestrial causes. In a later paper,! 

 in which he endeavours to harmonise the doctrines of 

 great ice-sheets and local glaciers, he admits that the 

 evidence from both Europe and North America " opposes 

 the theory of a great polar ice cap while favouring that of 

 a number of separate radiants." 



The great subsidence of the pleistocene period is 

 emphasised by recent discoveries of high-level glacial 

 gravels in England, which are described by Mr. A. C. 

 Nicholson, and which show a depression in that country 

 to the level of more than 1,300 feet. 



* American Geologist, December, 1890. 

 t Trans. Ed. Geol. Society, Vol. V. 

 J "Glacial Radiants," American Geologist, 1889. 

 " High Level Gravels at Gloppa," Journal Geological Society, 

 February, 1892. 



