THE SYRACUSE CHANNELS: MELTWATER MAYHEM OR PROGLACIAL TRICKLE?

In central New York, north of the Valley Heads Moraines and centered between Elbridge and Kirkville, exist a complex progression of large channels oriented E-W across portions of the northern edge of the Onondaga Escarpment. Known as the Syracuse Channels these meltwater features have been attributed to Late Wisconsin ice marginal drainage associated with the Ontario Lobe of the Laurentide Ice Sheet. Recently developed high resolution DEMs and new investigations by the New York State Geologic Survey reveal details that shed new light on these drainage features.

Many of the channels appear as conspicuous segments suspended on interfluves of the through valleys in the region. Morphologically the channels range in size from .25 km – 1km in width, 10-30 meters deep and continue as single channels for several kilometers. Channel forms crosscut drumlin fields, former ice marginal positions and appear to have been coincident with many large proglacial lakes. Channel incision occurs in both unconsolidated glacial deposits and Paleozoic sedimentary rocks. Some channel segments appear to be polygenetic in origin and may have been used multiple times to route drainage from earlier glacial cycles or recurrent ponding associated with ice-marginal fluctuations. The eastern ends of some channels terminate at bare rock surfaces possibly swept clean by high discharges of meltwater and some localities display stratigraphic, sedimentologic and geomorphic evidence supportive of catastrophic discharges. Alternatively, some channel segments likely formed as a result of incision from conventional meltwater processes.

Ground penetrating radar transects and exploratory drilling has just initiated to determine the stratigraphic and sedimentologic details of the channels with hopes of recovering datable material to better constrain the chronology of channel development. The Syracuse Channels directed meltwater into the ancestral Mohawk and down the lower Hudson River Valley. The source of meltwater may have been associated with elevated proglacial lake levels within the Erie basin or beyond or simply short duration, high magnitude discharges from localized proglacial basins and other cases perhaps good old uniformitarian meltwater processes.