TRACKING THE INTERACTION BETWEEN SURFACE WATER – GROUNDWATER IN GLACIAL DEPOSITS USING ELECTRICAL RESISTIVITY METHODS, CENTRAL NEW YORK

The region of central New York is underlain by Paleozoic strata of the Appalachian basin overlain by glacial till, peri-glacial and glacial lake deposits. Although drumlins dominate the landscape, there are outwash deposit, and numerous isolated basins that contain glacier lake deposits (now wetlands). These depositional environments have specific deposit architectures that control the distribution and movement of groundwater to and from the surface. During this investigation, 2D, 3D & 4D electrical resistivity surveys were conducted to characterize the distribution of the groundwater within specific deposits, characterize the transition between deposit types, and examine the connections between surface and groundwater systems over time. Four different drumlins were examined (McIntyre, Rice Creek, Cornish Hill and New Haven) and the transition with glacial lake deposits (Rice Creek and New Haven) and glacial outwash (Rice Creek, Fallbrook and New Haven). As well, the transition between outwash and glacial lake deposits was studied.

From these experiments the following conclusions have been reached concerning the distribution of groundwater and interaction with the surface: 1. Drumlin deposits have the most unpredictable groundwater distribution and surface interaction is by way of seeps and springs that are seasonal; 2. Outwash deposits have the most predictable groundwater distribution, and in once example the local glacial lake basin recharges the aquifer; 3. The remnant glacial lakes have deep confined aquifers in ground moraine that are recharged laterally through drumlin and outwash deposits. As well, there are always unconfined perched aquifers that reside on varve clays and within post-glacial gravel, sand, silt and peat deposits. In the two wetlands studied, there appears to be little vertical communication between the surface water and deep confined aquifer, but lateral communication exists with aquifers in outwash and drumlin deposits.