MAIN MORAINIC SYSTEM OF THE SCIOTO LOBE. 397 



system is feebler and the aggregation less close than in the western, the 

 majority of knolls are but 8 to 10 feet in height. In portions of Ross 

 County, however, the outer belt is strong, especially between Adelphi and 

 Hopetown, where the moraine swings westward to the Scioto Valley. The 

 larger knolls there are commonly 20 to 40 feet high, and associated with 

 them are numerous lower ones. Some near Hopetown, noted by Wright, 

 are about 100 feet in height. They are, in fact, short gravelly ridges, with 

 a trend nearly at i-ight angles with the course of the moraine, and may be 

 allied to eskers. Several large gravelly ridges occur on the west side of 

 the Scioto between Paint Creek and North Paint Creek about midway 

 between Chillicothe and Frankfort. These ridges interlock and inclose 

 deep basins. Their height is in some instances 150 to 175 feet above 

 lowland tracts east of them, but scarcely half that above their western 

 bases, which are on a hillside slope. 



The terraces and gravel plains along the Scioto River from Circleville 

 southward seem to pertain chiefly to the inner member of this morainic 

 system. A gravelly tract several miles in width, known as the Pickaway 

 Plains, leads down the river from Cii'cleville. It is dotted here and there 

 b}^ drift knolls and ridges of considerable size, and in many places its sur- 

 face is gently undulatory, but fully one-half the district presents a plane 

 surface. Its variations in topography are probably due to the combined 

 effect of an overhanging ice sheet and a discharge of water from the melting 

 ice. The plane portions of this gravelly area vary somewhat in their 

 height above the Scioto, being about 40 feet in the vicinity of Circleville, 

 while 8 or 10 miles below they are fullj^ 50 feet. This difference is not 

 due to an increase in the altitude of the gravel plain, but to a greater 

 rate of fall of the river, there being a fall of about 50 feet in the stream 

 between Circleville and Chillicothe, a distance of but 18 miles in direct line. 

 The occasional drift knolls on the gravel plain apparently indicate that the 

 ice margin overhung the Scioto Valley for at least 10 miles below Circle- 

 ville at the time the later moraine was forming. The terraces along the 

 Scioto are discussed on a subsequent page. 



The morainic features among the hills of western Ross Count)" are 

 variable. Some of the larger knolls have already been referred to. There 

 are others in the valley of Paint Creek whose height reaches 100 feet or 

 more, and others in a group near Lattas are equally high. Aside from these 



