WARREN UPHAM, ESQ., ON CAUSES OF THE ICE AGE. 217 



altitude, must have brought chmatic conditions under which 

 the ice would very rapidly disappear. The depression would 

 be like coming from Greenland to southern Canada and New 

 England. In Prof. Dana's words : "Such an extended change 

 of climate over the glacier area was equivalent in effect to a 

 transfer from a cold icy region to that of a temperate climate 

 and melting sun. The melting would therffore have gone 

 forward over vast surfaces at once, wide in latitude as well as 

 longitude."* 



36 Such explanations as these accounting for the gradual 

 accumulation and comparatively rapid dissolution of the North 

 American ice-sheet are also found to be applicable to the ice- 

 sheets of other regions. The fjords of the northern portions 

 of the British Isles and of Scandniavia sho\\^ that the drift- 

 bearing north-western part of Europe stood in preglacial 

 time 1,000 to 4,000 feet higher than now, while on the other 

 hand late glacial marine beds and strand lines of sea erosion 

 testify that Avhen the ice disappeared the land on which it had 

 lain was depressed iOO to (iOO feet beloAvits present height, or 

 nearly to tlie same amount as the Champlain depression in 

 North America. Mr. T. F. Jamieson appears to have been 

 the tirst in Great Britain or Europe to attribute the ice 

 accumulation to altitude of the land, and to hold the view, 

 which I receive from him, that the submergence of glaciated 

 lands when they were loaded with ice has been caused 

 directly by this load pressing down the earth's crust upon its 

 fused interior, and that the subsequent re-elevation v/as a 

 hydrostatic uplifting of the crust by underflow of the inner 

 mass when the ice was melted away.f Just the same 

 evidences of abundant and deep fjords and of marine beds 

 overlying the glacial drift to heights of several hundred feet 

 above the sea are found in Patagonia, as described by Darwin 

 and Agassiz. On these three continental areas, the widely 

 separated chief drift-bearing regions of the earth are found 

 to have experienced in connection with their glaciation in 

 each case three great epeirogenic movements of similar 



* Tram. Conn. Acad, of Arts and Sciences^, vol. ii, 1870, p. 67. Compare 

 the Am. Jour, of Science, III, vol. x, pp. 168-183, Sejit., 1875. 



t Quart. Jour. Oeol. Sue, vo). xviii, 1862, p. 180 ; vol. xxi, 1865, p. 178. 

 Later dificus-ions of this subject by Mr. Jamiesson are in the (Jeoloiiical 

 Magazine, II, vol. ix, pp. 400-407 and 457-466, Sept. and Oct., 1882 ; 

 III, vol. iv, pp. 344-348, Aug. 1887 ; aud III, vol. viii, pp. 387-302. Sept., 

 1891. 



