62 



H. L. FAIRCHILD — ICE EROSION THEORY A FALLACY 



somewhat variable, but none of them are the typical U shape of the 

 glaciated mountain valleys. 



Rock cliffs. — A large part of the shores not only of Seneca and 

 Cayuga, but of the smaller lakes as well, are nearly vertical rock cliffs. 

 These may be regarded as the product of wave work on decomposable 

 shales that are intersected with innumerable joints, but there is abundant 

 testimony, of people living by the lakes and familiar with their features, 

 to the existence of submerged cliffs and ledges. These might be attrib- 



Figure 6.— Map of Cayuga Lake Shores at Union Springs. 

 From the topographic map. 



uted to wave work when the lakes had a lower level, before the differ- 

 ential northward uplift had lifted the outlets and so raised the water 

 levels to the present planes. Moreover, there are cliffs, at least in the 

 Seneca and Cayuga valleys, much above the present waters. These might 

 be credited to the local high-level glacial waters which occupied the 

 valleys during the ice retreat. 



