632 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



the Girard topographic sheet. South from Crossingville the east side of 

 Cussewago Creek is characterized hj numerous drift knolls, but the western 

 slope and part of the valle}' bottom is destitute of them. The majority fall 

 between 10 and 25 feet in height, but at Mosiertown there is a knoll fully 

 50 feet in height. 



Between Cussewago and French creeks there are no clearly defined 

 morainic tracts, though drift knolls 10 feet or more in height are not rare. 

 On the borders of French Creek Valley above Saegerstown, where the stream 

 crosses an old divide, there are a few low drift knolls among the rock hills, 

 the majority being less than 20 feet in height. East from Cambridge there 

 is an open valley to the mouth of Muddy Creek, but along its southeastern 

 slope sandy knolls occur and there are numerous knolls and ridges along the 

 east side of French Creek, above the mouth of Muddy Creek; the largest 

 of these are 25 to 30 feet in height. As a rule, the knolls are conical or 

 slightly elliptical, and the ridges short, one-fourth mile or less in length. 

 One ridge, however, was observed, about a mile southeast of Millers 

 station, which is sharp and narrow like an esker, has a northwest-southeast 

 trend, and is nearly one-half mile long. It rises to the uplands from near 

 the base of the eastern slope of French Creek Valley. Its height is 30 

 feet, more or less, and its breadth is 50 to 100 yards. 



Scattering knolls 10 to 20 feet high occur on the northwest side of 

 French Creek in northern Crawford County and along Comieautee Creek, 

 between Cambridge and Edinboro. Above Edinboro, in the vicinity of 

 McLaue post-oflfice, the valley is nearly filled with sharp drift knolls, the 

 largest of which are 30 to 40 feet in heig'ht. Among them basins are 

 inclosed. The ridges trend in various directions. Near the northern border 

 one, trends north-northwest to south-southeast, or about in the direction oi 

 the ice movement, but farther south, just west of McLane, are ridges which 

 trend nearly at right angles with it and lie directly across the course of the 

 creek. 



On the uplands east of Conneautee Creek drift knolls are very rare, 

 but east of these uplands, just above Waterford, in the valley of Le Boeuf 

 Creek, the moraine is finely developed. It consists principally of a ridge 

 that crosses the valley from west-southwest to east-northeast (the valley 

 having a north-south direction). Its highest points are 75 to 100 feet 

 above the flood plain of the creek. Its length is nearly a mile, and it so 



