28 W. UPHAM — DRUMLINS AND MARGINAL MORAINES. 



ican ice-sheet had been well explored in their main features from the 

 Atlantic coast to North Dakota, the first discoveries of the similar mar- 

 ginal moraines of the British and European ice-sheets were made less 

 than ten years ago by two American giacialists, who were specially quali- 

 fied for these observations by their previous work in the United States, 

 namely, Professor H. Carvill Lewis, in Great Britain and Ireland, and 

 Professor R. D. Salisbury, in Germany. It is now ascertained that there 

 are well defined belts of morainic drift hills in southern Sweden, Den- 

 mark, northern Germany, and Finland. The most conspicuous German 

 moraine belt is named the Baltic ridge, and the waning ice-sheet at the 

 stage of its formation is known as the great Baltic glacier. All these 

 moraines appear to belong to the same declining part of the Ice age, 

 being correlative with the Wisconsin stage of glaciation in the northern 

 United States.* 



Recognition of the Champlain Epoch in Europe. 



The general contemporaneousness of the Glacial period on the opi)o- 

 site sides of the North Atlantic ocean had been long accepted as prob- 

 able, but its demonstration and the identification of the corresponding 

 jmrts of the Ice age, having the same sequence on the two continents, were 

 first made known last year by the studies of Geikie and Chamberlin in 

 the new third edition of " The Great Ice Age," and by their later papers 

 this year in the Journal of Geology, as already cited. Not only are the 

 Kansan and lowan stages of culmination of the ice-sheets closely alike 

 for these widely separated great areas, but also the land depression of 

 the Champlain epoch in both North America and Europe brought marine 

 submergence of coastal tracts and caused rapid disappearance of the ice- 

 sheets, with the formation of their drumlins and marginal moraines. 

 These two continents were included in the portion of the earth's crust 

 which twice experienced far extended epeirogenic movements, first of 

 high uplift, bringing the cold climate and snow and ice accumulation 

 of the Ghicial period, and afterward of depression somewhat lower than 

 now, whereby the vast ice fields were melted away. 



Contrast of the Growth and Decline of the Pleistocene Ice- 

 sheets IN THEIR Deposition of Drift. 



During the growth and maximum advance of the ice-sheet on each 

 continent the border of tlie drift along the greater part of its extent was 



* For a correlation of the stages of the Ice age ia North America and Europe leading to the fore- 

 going explanation of the rapid accumulation of the marginal moraines, see the Am, Geologist, vol. 

 xvi, pp. 100-113, Aug., 1895, with maps of the Kansan, lowan, and Wisconsin boundaries of the North 

 American and European ice-sheets. 



