GLACIAL WATERS IN CENTRAL NEW YORK 



7 



GENERAL DESCRIPTION: PRELIMINARY OUTLINE 



The glacier acting as a barrier to northward drainage is the funda- 

 mental fact to be apprehended by the reader. The ice sheet was 

 a melting dam during both its advance and its retreat, and waters 

 were flowing copiously from it, not into it. Valleys or land depres- 

 sions sloping toward the ice front were by the ice barrier made 

 into lake basins [see pi. 34-42]. 



The earliest outlets for the ice-dammed waters were at the heads 

 of the greater valleys, or across the cols, to southern drainage. A 

 later escape of the waters was by flow past the ice margin across 

 the ridges between the lakes, thus draining higher valley lakes into 

 lower lakes. These cross-ridge outlets were successively lowered 

 and shifted northward as the ice front receded, until at lower levels 

 the proglacial drainage formed extended rivers on the intervalley 

 stretches. Rivers of glacial water had no less power of carv- 

 ing channels and building deltas than other streams, and these 

 effects of the ancient rivers are still conspicuous evidence of their 

 existence. 



West of Batavia all the glacial waters escaped westward to the 

 lakes held in the Erie basin [see title 37, p. 10] and ultimately to the 

 Mississippi river. The same is true of all the waters held in the 

 Genesee region under about 1200 feet (the lowest southward escape 

 of Genesee waters; see title 40). This is probably true, also, of all 

 the glacial waters of central New York between the Newberry 

 plane (about 1000 feet on the Batavia parallel) and 900 feet, the 

 elevation of the lowest west-leading channels at Batavia. All the 

 drainage under 900 feet was eastward past Syracuse to the Mohawk 

 valley. These east-leading channels, from their heading near Leroy 

 to beyond Syracuse, form the subject of the present writing. 



The general history may be clearer if the physiography of the 

 region is emphasized. In the territory between the meridians of 

 Batavia and Syracuse, covered by the accompanying maps and plates 

 1-5, at least 13 distinct valleys lie sloping northward. Named in 

 order from west to east these are Oatka, Genesee, Conesus, Honeoye, 

 Bristol (Mud creek), Canandaigua, Flint, Seneca, Cayuga, Owasco, 

 Skaneateles, Otisco and Onondaga. The higher and more local 

 glacial waters in these valleys had different outflow seeking south- 

 ward escape, but a later stage saw the waters of the broad area 

 collected mainly into two large lakes. One of these was Lake New- 



