ESKERS IN THE VICIXITY OF ROCHESTER, NEW YORK. 231 



It is associated with the Albion moraine, lying to the north of 

 it, the moraine making a jog southward from its regular trend and 

 passing through Clarendon beyond the southend of the esker (62). 

 The Albion topographic map exhibits the esker and associated 

 features clearly. 



The esker ridge rises rather abruptly at its north end, the coun- 

 try north of its place of origin being uneven with gravelly knolls 

 abounding. In fact these knolls parallel its course on either side and 

 are especially numerous beyond its southern termination around 

 Clarendon. 



Its course is of the meandering type, the meanders being long 

 and conspicuous. The ridge is unusually broad at its base, a feature 

 not characteristic of Western New York eskers, and its crest is like- 

 wise unusually broad. Its lateral slopes are gentle, much more so 

 than those of the ordinary esker. They are stony yet yield a fairly 

 good soil consequently the ridge is under cultivation its entire length, 

 part of it being in orchard. The crest-line is uneven or hummocky, 

 the highest one being "Indian Hill" which rises 45 feet above the 

 adjoining portion of the ridge on the north. 



From the point of origin to the place of termination no inter- 

 ruptions occur in the course of the esker, it being continuous 

 throughout its entire length. 



Its termination is gradual. From "Indian Hill'' it slopes south- 

 westward, first rapidly and then more gently until it has ceased to 

 appear as a distinct ridge among the irregularities of the ground 

 moraine on either hand. 



At least two gravel pits occur in its course. Neither has been 

 worked recently so that their features are obscured by weathering. 

 The bedding is imperfect and indistinct near the surface, becoming 

 more distinct with rude anticlinal structure with depth. The mate- 

 rials are fine, chiefly gravel of good grade. This is composed almost 

 entirely of Medina sandstone, a formation that is extensively worked 

 at Holley for building stone. Leverett states that ]\Iedina makes up 

 90 per cent, of the pebbles by actual count (62). 



One small tributary esker occurs just east of the north end of the 

 main ridge. It is about 800 feet long with a hummocky crest, the 

 hummocks rising to a height of 20 feet above the surface on either 

 side of the tributary. 



