CHANGES IN LEVEL OF THE LAND 3038 
affected the whole northeastern part of our continent. 
An old lake in the valley of the Red River of the 
North also built shore lines which bear like witness. 
Hence from Minnesota and Manitoba to Labrador and 
New England, the land has been raised, and the north 
lifted higher than the south. In some places this 
uplift is still in progress. 
wn oo ealonag > Soa 
Fic. 177. 
Ancient beach above present level of Lake Michigan. 
This evidence from the lake shore lines of the 
interior is also proof of land movement; for of course 
changes in sea-level cannot account for the differences 
in level of these beaches. We may, therefore, conclude 
that the variation is usually one of the land, and that, 
while a change in the level of the sea is certainly possi- 
ble, there is as yet no evidence that it has really caused 
any of the recorded elevations or depressions. 
