390 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



It will be observed that the gravelly knolls in the valley, as well as 

 the level-topped gravel deposits, are included by Professor Wright in the 

 terrace. In the writer's description the terrace is considered to have its 

 head where the level-topped gravel deposit begins. The gravelly knolls 

 are included in the moraine, since they owe their existence largely to the 

 mechanical agency of the ice sheet, like portions of the moraine on the 

 uplands. With this in mind the reader will find no difficulty in harmonizing 

 the two descriptions. 



The moraine fills the valley for a couple of miles north from the 

 glacial boundary. There is ..then an interval of 3 miles or so where the 

 valley is comjsaratively open, and is bordered by a low plain nearly 

 one-half mile in width. Near Holmesville this low plain rises into a gravel 

 terrace, and about three-quarters of a mile north of that village the terrace 

 heads in the middle member of the morainic system. At its head it stands 

 35 or 40 feet above the creek. It is well displayed on the east side of the 

 valley. In the western portion of the valley there is a low plain which has 

 no connection with the middle member, but passes entirely thi'ough it and 

 also through the inner member, the middle and inner meixibers extending 

 down to the borders of the plain on either side of the valley. The width of 

 the plain is nowhere less than one-fourth mile, and in the vicinity of Wooster 

 it expands to a mile or more. It was occupied by glacial waters at a later 

 date than the time when this morainic system was being formed, probably 

 while the ice margin stood near the continental divide. The inner member 

 crosses the valley 2 to 4 miles below Wooster, but no terrace was dis- 

 covered in connection with it. The morainic knolls in this valley seldom 

 exceed 30 feet in height, and more commonly are but 10 to 16 feet. 



Between Killbuck Creek and Lake Fork of Mohican Creek there are, 

 near the southern border of the drift, large dome-shaped hills, 50 to 100 feet 

 in height, covering 20 to 40 acres or more each, which probably contain in 

 every case a nucleus of sandstone, but whose outline is markedly in con- 

 trast with that of unglaciated hills near them on the south. In one large 

 hill, about a mile south of Nashville, the north slope was smoothed, like its 

 neighbors, hj the ice sheet, while the south side remains rough, like hills 

 in the unglaciated district, and is covered by immense detached masses of 

 sandstone. The drift knolls in this district are but 10 to 20 feet high. 

 They present fresh contours out to the very borders of the glaciated district. 



