G. F. Wright — Continuity of the Glacial Period. 167 



moraine is about forty feet higher. The overwash terrace plane 

 declines southward, so that at Warren it is but a little over 

 1200 feet above tide. The trough averages, I should say, about 

 half a mile in width, and is bordered by hills to a height of 

 about 2000 feet above tide, or from TOO to 800 feet above the 

 present valley. 



Figure 3. 



Between the lower terrace referred to and the higher hills 

 there are the remnants of a rock shelf which is about 200 feet 

 above the present level of the Allegheny River, and as the 

 Allegheny and Conewango are both partially filled with gravel, 

 this shelf is about 250 feet above the rock bottom of these 

 streams, and is covered to a depth of from twenty to fifty feet 



