OUTWASH IN THE GRAND RIVER LOBE. 463 



deep, but since these are located in the moraine west of the river they are 

 more propo'ly discussed in connection with that moraine. On the east 

 side of the river from Ravenna northward the drift is not thick, and out- 

 crops of rock are numerous. The greatest amount noted was 66 feet, in 

 H. C. Babcock's well, in the southwest part of Shalersville Township. 



BOWLDERS. 



Over nearly the whole of tliis morainic system bowlders are a common 

 feature on the surface, and they are to a considerable extent incorporated 

 in the surface portion of the drift. A few places were noted where they are 

 especially numerous, viz, near Salem, Ohio, along the inner part of the knob- 

 and-basin portion of the moraine; in Beaver, Lawrence, and Mercer coun- 

 ties. Pa., in the outer part of the moraine, and along French Creek, in 

 western Venango County,, north of Utica. The bowlders seem to be 

 scattered broadcast rather than confined to narrow belts. 



CHARACTER OF THE OUTWASH. 



In the description of the moraine, numerous references have been made 

 to moraine-headed gravel terraces and gravel aprons which connect closely 

 with the moraine and clearly represent the outwash from it. These terraces 

 in most cases merge at their heads into the gravelly knolls of the moraine. 

 They usually descend somewhat rapidly for the first few miles, beyond 

 which their slope is more gradual, differing but little from that of the 

 present stream bed. They lead down the tributaries of the Allegheny to 

 the main stream, and thence down to the Ohio and along that valley as far 

 down as the mouth of the Muskingum, where contributions from the Scioto 

 lobe have been received. 



The material is so coarse as to indicate a current of considerable 

 strength. It is coarser than that readily transported by the present streams 

 except in their flood stages, and seems to indicate that the streams then had 

 at times a volume fully as great as the present greatest flood stages. The 

 silt and fine sand, which are now such conspicuous ingredients in the flood 

 plains-,^ the Ohio and Allegheny rivers and their tributaries, were swept 

 away from their glacial valley deposits; as a conseqiience, the glacial 

 terraces are composed largely of gravel, some of which is very coarse. 



