ESKERS IX THE VICINITY OF ROCHESTER, NEW YORK. 215 



The greater portion of this esker is under cultivation, in fact 

 its surface is better suited to cultivation than the adjoining wet 

 swampy ground, with its small ponds containing stagnant water. 

 The ridge terminates northward in a comparatively flat swampy area, 

 southward it gradually fades out and blends with the ground 

 moraine. 



East of the southern half of the esker and between it and the 

 highway occurs a series of knolls resembling kames. The topo- 

 graphic sheet indicates several of them. They are joined by low 

 intervening ridges except in one or two instances where deposition 

 between the knolls apparently was lacking. The northernmost of 

 these knobs is separated from the rest by a swamp and is attached 

 to the eastern slope of the esker. Its surface is under cultivation as 

 in the case of the knolls, and it is not excessively stony. This series 

 of knolls may be regarded as a parallel esker or as a series of kames 

 originating as a result of the deposition of detritus (formed by a 

 superficial or subglacial stream) at the edge of the ice or in a re- 

 entrance of the ice, the localization of accumulation being due to the 

 wavering retreat of the ice. 



Ridge B. About one mile north of Ridge A occurs another 

 esker segment closely paralleling the base of a lofty drumlin, to 

 which it is joined in two places. For the most part it is low, being 

 less than 20 feet high. Several gaps occur in its course, one or two 

 of which are probably due to stream erosion. Near the northern 

 portion of the ridge a shallow kettle occurs in its highest part ; here 

 the ridge is about 50 feet wide across its crest. 



The southern portion of this ridge exhibits a notable tendency 

 to meander. It terminates southward in a kame area, the surface of 

 which is very stony. Some of these stones may have been derived 

 from the erosion of the esker itself. 



The northern portion of Ridge B is its highest part. Here a 

 detached segment 500 feet long and 25 to 30 feet high rests upon an 

 elevated surface which is apparently of till, possibly being a broad 

 flat drumlin. 



This segment is densely wooded, its crest is unusually level and 

 rather broad, its termination on the south is very abrupt and its ini- 

 tiation northward is of equal abruptness. It is succeeded northward 



