628 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



feet. The swells are 10 to 20 feet or more in height, closely aggregated in 

 places, and everywhere so associated as to give a decidedly morainic aspect 

 to the belt. An especially pi'ominent cluster of knolls appears on the line 

 of Hampden and Montville townships, about a mile from their southern 

 boundary, where, over an area of about one-fourth of a square mile, the 

 knolls are closely aggregated and rise sharply to heights of 10 to 40 feet. 



Upon entering Trumbull County the moraine descends into Grand 

 River Valley and is well defined on the slopes, though its knolls are low, 

 seldom exceeding 15 feet in height. In the Grand River Valley, in 

 Southington and Champion townships, its surface is uneven, with changes 

 of level as great as 25 or 30 feet within a half mile, but there are few if 

 any sharp knolls. This unevemiess is due to irregularity of drift deposi- 

 tion rather than to postglacial erosion, and the well sections show it to be 

 entirely independent of the rock floor under the valley. The moraine 

 presents here a nearly continuous ridge, which rises gradually on the inner 

 border, but rather abruptly on the outer. Two notable gaps occur in it, 

 each about a half mile in width. One, near the southeastern corner of 

 Champion Township, affords an easy passage for the Pittsburg, Youngs- 

 town and Ashtabula Railroad; the other is utilized by the Painesville and 

 Youngstown Railroad. Neither of these railroads has made cuttings in 

 crossing the moraine, but if they had been built across the stronger portion 

 either a steep grade or a cutting of 20 feet would have been required. 



In the vicinity of Mosquito Creek only scattering knolls occur, the 

 moraine being weaker there than at any other part of the loop that 

 surrounds the Grand ,River Valley. On the uplands east of Mosquito 

 Creek, in Mecca, Johnson, and Gustavus townships, it is well defined, 

 having closely associated knolls 10 to 15 feet high, with shallow basins 

 among them. 



Two miles north of Kinsman, in the valley of Pymatuning Creek, is 

 one of the most prominent hills in the moraine. It rises abruptly to a 

 height of 80 feet, is about one-fourth mile in length and one-eighth mile 

 in breadth. Its trend is nearly at a right angle to that of the moraine, 

 being northwest to southeast. It is highest and most abrupt at the 

 northwestern end, its slope having there an angle of 35° or 40°. At the 

 southeastern end it drops down gradually and merges into a pitted gravel 

 plain which leads down Pymatuning Creek. The pecuhar structure of 

 this hill is discussed on page 641. 



