OUTWASH OF ILLINOIAN AGE. 287 



the dam was accumulating a lake probably occupied the valley to the east. 

 The filling is largely a fine silt of blue color, capped by a few feet of gravel 

 and sand. The amount of filling has been sufficient to cause a new chaimel 

 to be opened by the Licking for a short distance in the vicinity of the drift 

 border. 



In the tract lying between the Licking and the old valley of the 

 Muskingum, east ^rom the drift border as far as the present valley, there has 

 been a general filling up of valleys, not only on the main lines of drainage, 

 but also on the tributary lines. Much of the filling is a fine silt, but the 

 surface, as in the dam at the drift border, is of coarser material. In some 

 of the tributary valleys small drift pebbles have been observed on the 

 slopes up to a level 25 feet or more above the flat valley bottoms, a feature 

 which seems to indicate that the region has been submerged to levels above 

 the valley bottoms. It is suggested that the prevailing west winds may 

 have carried cakes of ice laden with pebbles from the vicinity of the drift 

 border eastward into these valleys, passing, in some cases, over low divides, 

 and thus distributing them outside the range of the present system of 

 drainage. 



The glacial lake which was held in this portion of the Muskingum 

 Valley discharged southward to the Ohio across the old divide south of 

 Zanesville. The volume of its discharge was probably much greater than 

 that of the present Muskingum, since it appears to have carried nearly all 

 the drainage of the ice field in northeastern Ohio. The high-level gravels 

 below the old divide at McConnelsville, and at points farther down the 

 valley, may prove to have been deposited by the glacial waters crossing 

 this divide. But as yet this is merelj" a matter of conjecture. The gravel 

 at McConnelsville has an aged appearance quite similar to that of the 

 glacial gravels connected with the lUinoian drift, and decidedly in contrast 

 with the fresh gravels of Wisconsin age, which occur at lower levels in the 

 valley. In this connection it may be remarked that gravel of Wisconsin 

 age has been deposited in such large amount along the line of the Licking 

 below Hanover and along the entire length of the Muskingum that the 

 outwash from the earlier ice field has been rendered rather obscure, except 

 at the great dam near Hanover. 



