GLACIAL WATERS IN CENTRAL NEW YORK 



27 



heads 4 miles north of Skaneateles and a mile northwest of Shepard 

 Settlement delta, at an elevation by the map of 820 feet. The 

 bare limestone at the intake covers many acres, the appearance 

 being well shown in plate 18, a characteristic view of a water- 

 swept limestone surface. It is apparent that the great channel 

 was not cut by merely local waters, for the features require the 

 work of an enormous volume of water. The depth of the gorge is 

 from 100 to 150 feet. The width of the bottom of the channel is 

 from J to I mile, and the walls are flaring and not vertical, as the 

 rocks are Marcellus shale [see pi. 19, fig. 1]. In the head of the 

 gorge is a low cascade slope with two lakes (Mud Pond) at the foot. 

 The altitude of the lakes is slightly under 800 feet and the decline 

 of the channel bottom in the 5 miles to Ninemile creek valley is 

 about 80 feet. 



The map clearly shows how the channel widens as it joins the 

 Ninemile (Marcellus) valley and ends in a huge fan delta. The 

 currents of the heavy flood swung to the north through the narrow 

 Marcellus lake to find their escape at Marcellus by the Marcellus- 

 Cedarvale-South Onondaga channel. With the down-cutting of 

 the latter gorge and consequent lowering of the Marcellus waters 

 the inflowing river carved its delta into terraces with steep , curving 

 fronts. These conspicuous erosion features on the delta can 

 be plainly seen from the electric railway. 



The highest portion of the delta, on the northwest side, reaches 

 up to about 880 feet, and consists, as would be expected, of very 

 coarse and poorly assorted material. The curving bluffs of erosion, 

 representing the left-hand river banks, occurring at levels from 

 about 860 down to about 760, mark the successive hights of. the 

 falling lake as determined by the Cedarvale outlet. 



It is possible that some portion of the mass of the Gulf delta is 

 moraine drift, as a heavy moraine lies against the delta on the 

 south. 



The body of water of small dimensions held in the Marcellus 

 section of the Otisco valley during the life of the Gulf river has 

 been named the Marcellus lake, it being the third in falling suc- 

 cession of the local glacial waters in the valley. The surface alti- 

 tudes of this water were determined by the hights of the east- 

 leading channel, the down-cutting of which accounts for the delta 

 terraces and curving banks noted above. 



The head of the Cedarville channel is at the southeast edge of 

 the village of Marcellus, some 50 feet above the Ninemile creek, 



