EPEIROGENIC MOVEMENTS EFFECT ON ICE AGE 5 



Lantern slides were used to show the appearance of the strata and 

 blue bands in different parts of the glacier. The paper will be printed 

 in the Journal of Geolog^y. 



The following paper was then read: 



EVIDENCES OF EPEIROGENIC MOVEMENTS CAUSING AND TERMINATING THE 



ICE AGE 



BY WAKKEN UPHAM 



Contents 



Page 



Introduction 5 



Preglacial liigh elevation known by fiords and submerged valleys 6 



West coast of North America 6 



Interior of North America 7 



Atlantic borders of the United States and Canada 7 



Arctic America and Greenland 7 



Western Europe and western Africa 7 



Competence of the preglacial epeirogenic uplift to cause the accumulation of the ice-sheets 8 



Late glacial or Champlain depression known by fossiliferous marine deposits overlying the 



glacial drift ;. 9 



North America 9 



Europe 9 



Competence of the Champlain depression to terminate the Ice age 9 



Introduction 



In our endeavor to ascertain the causes of the unique Ice age, forming the latest 

 completed period of the geologic record, we receive from Lyell, Dana, and Le Conte 

 the recognition of three great vertical movements, now denominated epeirogenic, 

 which were experienced by each of the three great regions of the earth that are 

 overspread by glacial drift, namely, the northern half of North America, the north- 

 western half of Europe, and Patagonia. Their series of epeirogenic movements in 

 each case were, first, a preglacial general uplift to a vertical extent measured by 

 the depths of their fiords and submerged valleys, that is, 1,000 to 8,000 feet above 

 their present heights ; second, a general depression in the Champlain epoch, clos- 

 ing the Ice age, to levels somewhat lower than now ; and, third, a recent general 

 re-elevation, varying in vertical amount up to at least 600 feet in North America, 

 nearly as much in Patagonia, and about 1,000 feet in Scandinavia. The purpose of 

 the present paper is to review the evidences of these epeirogenic movements in 

 North America and Europe, and to inquire whether they were probably sufficient, 

 in their influence on climatic conditions, to cause, by the high land altitude, the 

 accumulation of the ice-sheets of these continents, and hj the ensuing depression, 

 to bring the comparatively sudden end of the Glacial period, with the mainly 

 rapid, though fluctuating, departure of the ice-sheets and deposition of their drift. 

 Since tlie announcement by Dana, more than forty years ago, of the threefold 

 oscillations of this continent respectively preceding, during, and after its glaciation, 

 detailed hydrographic surveys of submerged valleys on both our Atlantic and Pa- 

 ■ cific coasts have demonstrated a vertical extent of the preglacial uplift far exceed- 

 ing its known amiount when the attention of geologists was thus first directed to it. 

 No doubt need be longer entertained that its climatic effect could and did induce 

 the general glaciation of the cool temperate and in part still frigid northern half 



