28 NEW YORK STATE MUSEUM 



and leads southeast with a width of J to ^ mile. The channel is 

 in Marcellus shale except at the intake, where it reaches the Onon- 

 daga limestone. About 50 rods east of the north and south road 

 which lies on the channel head the rock sill of the intake was cut 

 into a cataract with a fall of about 3c to 40 feet. In the shallow 

 and irregular basin below the cataract a lake of a few acres exists 

 in the wet season, but is said to drain off by fissures in the lime- 

 stone westward, under the cataract cliff, into the Xinemile creek 

 [pi. 20]. 



The rock strata at the head of this gorge, as well as all through 

 the region has a decided southward dip, with some flexures, the 

 latter being well shown in the quarries in the channel head. On 

 the north side of the intake the limestone is exposed and supports 

 the highways, but on the south side of the intake the Marcellus 

 shale is not entirely removed, being cut into three shallow channels 

 with two intervening ridges, plainly seen from the north and 

 south road. Taking as datum the United States Geological Survey 

 bench mark on the coping of the bridge in the village, 653 feet, 

 the elevations at the channel head are as follows: limestone at 

 northeast angle of the channel head, over 700 feet; at the road 

 corners, north side, 696 feet; channel in shale farthest south 685 

 feet. 



The map shows better than verbal description the great ancient 

 waterway, with its several branches and very extensive deltas. 

 As a whole the channels and deltas are the most imposing among 

 such features in Xew York State. The total length of the Cedar- 

 vale channel from Marcellus to the Indian Village in the Onon- 

 daga valley is nearly 12 miles, measured in its windings. A11 but 

 the upper 3 miles lies in a broad preglacial valley which the river 

 has largely filled with its delta rubbish ; depositing first at the 

 higher levels, then reexcavating and redepositing at lower and 

 lower levels as the base level of the stream was lowered. The 

 delta is of magnificent size and form even in its present fragmen- 

 tary state. Erosion has left it in two distinct masses. The upper 

 forms a great plateau south of Cedarvale post office, with two levels, 

 the higher one declining in terraces from 860 feet (using the map 

 contours) to 820 feet, the lower one being 6S0 to 660 feet. The 

 preglacial valley, at least 2 miles wide on the Cedarvale meridian, 

 must have been entirely filled with the delta, as fragments are 

 found north of the Cedarvale channel and on the south border of 

 the valley. That the present channel at Cedarvale, | mile wide 



