216 ROCHESTER ACADEMY OF SCIENCE. 



by a kame area that is bounded on the east by a steep slope about 20 

 feet high. 



Ridge B is bordered on the east for a considerable part of its 

 course by a long parallel ridge of about 25 feet in height. 



Ridge C. One-fourth to one-half of a mile north of Ridge B 

 occurs the third part of the esker. It proceeds northward from the 

 kame area that terminates Ridge B on the north, the steep eastern 

 edge of the kame area forming the eastern side of Ridge C. 



This portion of the esker system trends northward for one- 

 fourth of a mile or more as a well-defined ridge 15 to 25 feet high 

 with steep slopes and a meandering course through swampy ground. 

 Knolls along its crest are common. The excavations for gravel 

 here show material of uniform grade and medium size. Sand is 

 lacking, and few large boulders occur. 



In the northern part of the esker two shallow kettles are de- 

 pressed into the ridge, ^^'here these kettles occur the ridge exhibits 

 a tendency to become low and broad, while on either side the esker 

 rises abruptly to the normal height. The slopes leading into the 

 kettles and outward from their rims are very gentle. 



Northward the esker terminates rather abruptly in a swamp. 



Ridge D. This northermost segment of the esker system lies 

 between two high drumlins bordered by swampy land with small 

 ponds on either side. It is short, only about one-quarter of a mile 

 long, with a meandering course throughout its entire length. No- 

 where is its height greater than 30 feet. 



The southern portion of the ridge is of low altitude with uneven 

 crest, the northern part reaches a height of nearly 30 feet and has a 

 remarkably even level crest with steep and stony slopes that are un- 

 der cultivation. Northward this level-crested ridge terminates ab- 

 ruptly in a flat field, southward the esker blends with the high drum- 

 lin that parallels its cottrse on the west. 



Where the stream cuts through the esker there is an old excava- 

 tion which reveals a rude indistinct stratification. At least three- 

 fourths of the materials are from local formations. There is some 

 sand here on the eastern side of the excavation in which are em- 

 bedded numerous rounded stones. On the opposite side of the exca- 

 vation occurs sand near the surface, with numerous embedded 

 rounded stones. 



