SlGNincANrn of kskef: TKi^RAr-Ks 



285 



"At Warren the drive-pipes of oil wolls in niMiiy cmscs have l>eeii driven 

 through the gravels from a surface hundreds of feet above the present level 

 of the river to a depth 20 feet below the present water level, showing that the 

 Conewango Valley was degraded before the gravels were deposited, and the 

 river now flows on 20 feet of those gravels, and so 20 feet above the preglaeial 

 level of the valley. There is no roek shelf there, but an aggraded valley, with 

 bed 20 feet above its preglaeial level." 



Figure 3. — Topography East of Warren, Pennsylvania 



A is a hill, whicli deflected the glacial stream down the Conewango ; mi, mii, min, miv 

 and xi, xii^ xHi are places where wells have been sunk, revealing gravel as in figures 

 4 and 5. These high, level gravels at Warren are shown to be deposits of the Glacial 

 age in a valley that was entirely preglaeial. The force of the current was such that, 

 while leaving these gravels in the lee of hill A, it scoured them all away from the south 

 side of the Conewango. 



Significance of Esker Terraces 



The existence of "esker" terraces has also led, as I believe, both in this 

 country and in Europe, to a great exaggeration of post-Glacial time. 

 Two such series of terraces have come under my observation in Ohio, 

 namely, in the River Styx, in Medina County, between Seville and Wads- 

 worth, and in the Mohecan River, in Wayne County, in the vicinity of 

 Wooster. In both cases these streams flow southward from the water- 



