LAKES. 239 



narrow, and the banks rise to a considerable height, and abruptly from the lake. The water 

 line of the lake, with the exception of the south part, is excavated in the Hamilton group ; 

 the TuUy limestone and the Genesee slate appearing to the south of Borodino, rising when 

 first seen about one hundred and fifty feet above the lake ; and the Ithaca group, commencing 

 still further south, surrounds the head of the lake. The greatest depth appears to be south 

 of Borodino, the deepest sounding being 320 feet. This lake is about eighty feet higher than 

 Owasco lake. It is about fourteen miles long, and varying from about a half to a mile and a 

 quarter in breadth. 



Owasco Lake. 



With the exception of the foot of the lake where the Marcellus shales must appear, the 

 outlet near the village of Auburn being in the lower part of the mass, the whole of the lake 

 is in the Hamilton group. Its length is over ten miles ; its width at the south end about a 

 half a mile, increasing to a mile and a half at the north. The foot of the lake is flat and 

 covered with alluvial ; rolled stone is abundant on the east side of the foot, and sand-hills on 

 the west side, covered in parts with the upper deposit of Chittenango. Along the outlet the 

 water has uncovered numerous boulders of primary rock, and blocks of limestone, which 

 show the composition of the flat which forms the foot of the lake. At the head of the lake 

 is the fine broad deep valley in which Moravia and Milan are seated, the bottom of the valley 

 constantly rising going south for about fifteen miles. 



Cayuga Lake. 



This lake forms a part of the west boundary of the district. The northern part, to near 

 Springport, shows the Onondaga salt group, or the gypseous deposit. The range of the Hel- 

 derberg terminates a short distance below the same village. The Marcellus shales and the 

 Hamilton group range near the water line as far south as Bell's ferry and Goodwin's point, 

 where the lower edge of the Tully limestone comes within a foot of the lake, conceahng all 

 but that part of the group. As the limestone rises by the bending of the lake to the east, the 

 Hamilton group reappears, showing about sixty feet of height at Ludlowville ; from whence 

 it diminishes in height, and disappears to the north of Bloom's lime-kiln. The Tully lime- 

 stone first appears on the lake near the north line of the town of Genoa, curves apparently 

 with the group upon which it rests, and ends its course at the kiln. The two remaining 

 masses of the east side of the lake are the Genesee slate, and the Portage and Ithaca groups ; 

 they are first seen to the south of Salmon creek, and the slate disappears about half way 

 between the lime-kiln and the head of the lake. 



This lake is nearly forty miles in length, and averages about two miles in breadth, being 

 wider towards the middle than towards the extremities. The greatest depth is 396 feet. 



