346 



EARTH FEATURES AND THEIR MEANING 



Whittlesey beach is evidence that the elastic recoil, as it were, 

 from the weight of the mantling glacier did not begin until after 

 the draining of Lake Whittlesey. The determination by Taylor 

 that there is a similar initial hinge line in the Warren beach 

 that this strand begins its uptilt some fifteen miles farther north- 

 east than does the Whittlesey beach is one of the greatest im- 

 portance in obtaining a correct idea of the recent uplift ; for it 



FIG. 375. Series of idealistic diagrams to indicate the nature of the quick recovery 

 of the crust by uplift in blocks unloaded of the ice in succession. A further and 

 slower uptilt, added after the completion of the first movement, is brought out in 

 the last diagram (&') 



shows that the draining of Lake Whittlesey was followed by 

 a period of quick uplift and seismic activity, that the stage of 



