FOUNDATIONS OF THE GREAT DEEP 



35 



FIGURE 15. MAP SHOWING LIMITS OF THE LAST ICE-CAP ON FENNOSCANDIA. 



far advanced that the Fennoscandian geologists make that 

 epochal date the beginning of post-Glacial time. 



At the Bothnian center the mighty load had depressed the 

 earth's crust about half a mile, but less and less along the radii 

 out to the edge of the glaciated tract. During the slow. melting 

 and transfer of water back to the ocean, and ever since, most of 

 the glaciated region has been slowly rising. In leisurely but 

 unmistakable fashion the earth's crust has been recoiling from 

 its temporarily basined condition. Where the ice had been 

 thickest and heaviest the crust has risen most; where thinner, 

 it has risen less; and near the outermost moraine, not at all. 



The upwarp of the crust has been proved by the tilting of 

 sea-beaches and of beaches made by extensive, temporary lakes 

 which, during the retreat of the ice-front, were shored by the 

 ice-cap itself and by the rocky hills of the basined tract. The 



