22 NEW YORK STATE MUSEUM 



Properly they do not belong in the present writing but are briefly 

 introduced in this chapter in order to clarify the story. 



Conspicuous deltas occur at the foot of Otisco lake, with their 

 summit plateaus outlined by the contour of 940 feet. The streams 

 which built these excellent deltas headed near Xavarino and 

 Joshua with bottom altitudes of 1140 and 1020 feet, and evidently 

 carried westward the overflow of the ice-impounded waters of the 

 Onondaga valley. Across the ridge east of the Onondaga valley 

 we find a scourway at 1200 feet which carried the overflow of the 

 Butternut valley over into the Onondaga and dropped its detri- 

 tus 2 miles north of Lafayette at 1060 feet, correlating with the 

 Navarino channel. 



Looking to the west we find that the amber deltas at the foot of 

 Otisco lake had their level determined by the hight of the overflow 

 of the Otisco waters through a scourway 2 miles east of Skaneateles 

 village with altitude of 940 feet. The westward outflow from the 

 latter valley is below the field of this map, but lies at Mandana, 

 close to the west shore of the present lake and 6 miles south of 

 Skaneateles village, leading over to the Owasco valley, with alti- 

 tude of 900 feet. Thus we find a perfectly consistent series of inflow 

 and outflow of the glacial waters in the valleys from the Butternut 

 westward to the Owasco. 



Other west-leading channels at higher levels occur on the inter- 

 valley ridges, but they do not concern the present discussion. 



The question comes, where was the ultimate outlet for these 

 west-moving waters. In former writings it was supposed that 

 Lake Warren was the receiving water, in central Xew York. But 

 it has already been shown that the Warren waters did not invade 

 this part of the State until subsequent to the drainage epoch repre- 

 sented by the east-leading channels already described, excepting 

 perhaps the Fairport channel. The present writing is, therefore, 

 a correction of the former supposed relation of Lake Warren. 



It is apparent that the final escape of the waters must have been 

 at a level not greatly over 900 feet, since that is about the altitude 

 of the pass leading over to the Owasco valley. Only two possible 

 outlets can be found. One is the Horseheads channel, at 900 feet, 

 at the head of the Seneca valley, near the southern border of the 

 State, the outlet of Lake Xewberry; the other is the Batavia 

 scourways, 900 feet altitude. The north and south deformation of 

 the land since the glacial time has lifted the Xewberry plane on the 

 Skaneateles parallel not less than 80 feet above the outlet, or to 



