264 



Chamberlin and Leverett — Studies of the 



old stream may have followed the lower part of the Sheuango 

 in reverse as far north as Sharon, Pennsylvania (passing per- 

 haps through an abandoned valley, which leads across from 

 the Mahoning to the Shenango, between Edenburg and Har- 

 bor Bridge). From Sharon, it may have turned westward to 

 the Mahoning river at Youngstown, through a lowland tract 

 occupied by the Erie and the L. S. & M. S. railways, since at 

 Hubbard, Ohio, situated in the midst of this lowland, the rock 

 floor is found to be but 790 feet A. T., or about 100 feet 

 lower than the rock surface of»the gradation-plane on the 

 Beaver, at Wampum (about 40 miles south). The valley is 

 broader than that occupied by the Mahoning, a feature which 

 lends support to this route in preference to the direct one 

 through the latter valley suggested by Spencer and Foshay. 



The slope of the uplands lends some support to the theory 

 of northward discharge, there being a decline of about 200 

 feet between the mouth of the Beaver and Sharon, and an 

 additional decline of 50 feet to the border of the Grand river 

 basin (see profile B, fig. 3). 



Level of Lake Erie {S73' A.T.) 

 PROFILE B. (Scale Same as m A.) 



Fig. 3. Profile A shows the old gradation-plane, the buried channels, and 

 the present drainage of the Mahoning-Beaver system, between Niles, Ohio, and 

 Beaver, Pennsylvania, together with the old col at Lowellville. In this and in 

 profile B well sections are represented by vertical lines beneath the line of the 

 present stream. 



Profile B shows the old gradation-plane, the buried channels, and the present 

 drainage of the supposed old outlet of the upper Ohio between Beaver, Pennsyl- 

 vania, and Niles, Ohio. 



The hypothesis of northward drainage on the upper Ohio 

 derives support from the narrowness of the portion of its pres- 

 ent valley along that part of "West Virginia known as the 

 "Panhandle." The narrowness of this portion of the valley 

 has been a matter of remark by nearly all glacialists who have 

 traversed the region, the width being scarcely one-half as 

 great as on the portion of the Ohio between Pittsburg and the 



