VALLEYS AND RIDGES 451 



the highest levels of the region, a dozen of which are above 2,000 feet 

 and two above 2,250 feet. The south ends of the ridges are often very 

 abrupt, as in the case of High Point and Stony Lonesome. In many 

 cases the slopes have been oversteepened. Of this the west side of 

 Hemlock lake, both sides of the upper Honeoye valley, the east side of 

 High Point, and the west sides of Worden and Gannett hills are notable 

 instances. The east side of High Point has an angle of 40 degrees 

 (figure 1, plate 38). The steeper slopes are scored by hundreds of sharp 

 postglacial ravines, some of which are 200-300 feet deep, but they are 

 so narrow as to be inconspicuous from a distance, and the general ap- 

 pearance of the slopes is smooth. They are occasionally broken by flat 

 or gently sloping terraces of considerable width, due to the presence of 

 more resistant strata at that level. 



Canandaigua Valley 



It is not my purpose to enter upon a detailed description of the 

 Canandaigua valley, but only to note its relation to the other valleys 

 described. From Canandaigua it extends south-southwest 24 miles. 

 Its lower 16 miles is occupied by the lake with a maximum width of 

 one and one-half miles, narrowing to three-fourths of a mile at its head. 

 The lake surface is 686 feet above tide, while the plateau summits on 

 either side are 1,000-1,400 feet higher. At Naples, 4 miles above the 

 lake head, the valley, joined by converging tributaries, widens into an 

 amphitheater filled with deltas and moraines on a magnificent scale. 

 These have been described by Chamberlin* and Fairchild.f The valley 

 continues southwestward 4 miles, rising up the slope of the moraine 600 

 feet, and opens into the Cohocton-Wayland valley at the 1,400-foot level, 

 precisely as the Canaseraga valley opens into it 10 miles to the westward. 



Canaseraga Valley 



Canaseraga creek is one of the eastern tributaries of the Genesee, which 

 it joins near mount Morris. Its valley, straight, flat floored, swampy, 

 and more than a mile wide, extends east of south 15 miles to Dansville, 

 rising from 577 to 700 feet above tide. Above Dansville it is blocked 

 by a moraine, in every respect the counterpart of the moraine at the 

 head of the Canandaigua valley. With a step up of 600 feet in 2 miles, 

 it is continuous to the eastward with the Cohocton-Wayland valley. 



Cohocton-Wayland Valley 

 The east- west valley, 10 miles long and more than a mile wide, which 



* Third Report, U. S. Geol. Survey, p. :S54. 

 fBull. Geol. Soe. Am., vol. 6, p. 362. 



