OF DENISON UNIVERSITY. 37 



From the facts stated it seems certain that the main preglacial drain- 

 age of this region was ahnost directly east from New Lexington to 

 Lancaster. Tributary valleys of considerable size opened into this 

 main valley at various points, notably one from the north at Bremen in 

 the present position of North Fork, Rush creek. Also near same 

 place one from the south which was the westward continuation of the 

 Turkey creek valley. 



As the ice tongue which was pushed up this valley as far as 

 Junction City was withdrawn and while yet the mouth of the valley at 

 Lancaster was filled with ice, the waters were ponded back until they 

 rose over a col, located just on the county line between Fairfield and 

 Hocking, where the present Rush creek crosses, and found their way 

 southward into the Hocking. The position of this old col is so plainly 

 indicated by the surrounding topography that its location can be made 

 with certainty to within a hundred yards Just north of this valley the 

 waters ponded back by the main ice front crossed the divide at the col 

 near Rushville and scoured out the gorge from Rushville to Bremen, 

 thus finding an outlet southward along Rush creek. 



This torrent of glacial waters had so deepened the Rush creek 

 drainage, line and silted up the old valleys that when finally the ice 

 was withdrawn from the mouth of the valley at Lancaster the waters did 

 not re-occupy their old valleys but followed the glacial drainage lines. 

 The lower portion of the present Rush creek valley, south of the 

 county line, was occupied in preglacial time by a stream heading in 

 several small streamlets in the eastern portion of Marion township, 

 Hocking county. Towards its mouth it bore to the north-westward to 

 join the Hocking and not to the south-westward as at present. 



When it is borne in mind that many facts not stated herein seem 

 to indicate that the present Hocking is a reversed stream, it becomes 

 apparent that these preglacial valleys conform to the original preglacial 

 Hocking drainage and add more evidence to the support of the opin- 

 ion that the preglacial Hocking ran north-westward. And this in its 

 turn to the still larger problem of the central Ohio preglacial river sys- 

 tem formed from northward flowing streams which crossed the present 

 course of the Ohio river. One more link is thus added to the chain of 

 evidence in support of the view that the Ohio river along southern 

 Ohio owes its origin and position to glacial forces and does not date 

 back of the glacial period. 



