692 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



(Trumlins near Lockport and fartlier west stand in a very level region, 

 decidedly in contrast to that found in tlie druralin belt to the east. 



RANGE IN ALTITUDE. 



Although the di-umlins of this belt are all situated in the district 

 between the Niagara and Corniferous escarpments, the belt shows a range 

 of about 300 feet in altitude. They appear at the lowest altitude near 

 the Grenesee Kiver, 525 to 550 feet, and at the highest altitude in eastern 

 Elba and northern Stafford townships in the Albion quadrangle, where 

 their crests, in a few instances, rise above the 820-foot contour. It should, 

 perhaps, be explained that there are other drumlins near tlie shore of Lake 

 Ontario (some of which appear in PI. Ill) that are not in the belt under 

 discussion. 



TOPOGRAPHY. 



The usual form assumed by the drumlins in this region is an elliptical 

 smooth-surfaced knoll, a mile or less in length and scarcely one-fourth mile 

 in width, but in places they are elongated to 10 or 12 times their width 

 and reach a length of 2 miles or more. They trend in a general northeast- 

 southwest direction, with variations of perhaps 20° on either side of a due 

 northeast- to-southwest line. The northeast end shows a tendency to be more 

 abrupt than the southwest, though a large proportion of the drumlins are 

 very symmetrical. Where the sides are not symmetrical the southeast is 

 usually the more abrupt. The height ranges from 10 or 15 feet up to 

 about 100 feet, but in the majority it is not far from 40 feet. The most 

 prominent drumlins are in northern Elba Township, the one utilized for 

 the Parker geodetic station being about 105 feet above the Oak Orchard 

 Swamp, only one-fourth mile to the north. Two miles farther west a knoll 

 of gravelly constitution and less regular form than the typical di'umlin 

 stands 130 feet above the bordering swamp. 



The knolls and ridges which occur among the drumlins and along the 

 south border of the belt are of various shapes and sizes, as may be seen to 

 some extent in PI. III. There are with these knolls and ridges small, 

 nearly plane areas carrying shallow basins. Such areas are usually 

 gravelly, and present the appearance of the pitted outwash plains that 

 border moraines. These pitted plains occur at intervals along the north 

 side of Aliens Creek from Scottsville westward to the bend north of 



