CONTINUITY OF AQUIFERS IN GLACIAL DEPOSITS: A REGIONAL INVESTIGATION USING ELECTRICAL RESISTIVITY METHODS AT THE RICE CREEK FIELD STATION, OSWEGO, NEW YORK

Over the past 6 years, a series of high-resolution electrical resistivity experiments were conducted to characterize the interaction between surface- and groundwater in glacial till at the Rice Creek Field Station, Oswego County, New York. Each of these investigations were conducted at discrete field locations with the objective of characterizing aquifers with specific glacial deposits, ranging from tops and flanks of drumlins, outwash deposits, ground moraine, and glacial lake deposits that occur in low lying wetlands between drumlins. The current electrical resistivity investigation was carried out to connect the individual field sites and to understand the regional continuity of aquifers across and between various types of glacial till. A continuous electrical resistivity survey was completed over a line distance of 3.2 km using an automated ER meter, 3 meter node spacing and standard Wenner array. The depth of ER imaging was about 11.5 meters. From these experiments the following conclusions have been reached concerning the continuity of aquifers in glacial deposits: 1. The top of two drumlins were investigated and both deposits have the least aquifer continuity with isolated aquifers that span 10’s of meters, and many small perched aquifers. 2. The transition to the flank of the drumlins shows continuous unconfined aquifers that transition into outwash deposits at the base. 3. Within the outwash deposits, the aquifers discontinuous and appear to be best developed in paleo-channel deposits. 4. The outwash deposits transition into glacial lake deposits where the aquifer continuity increases. Continuous perched aquifers correlate with surface water in wetlands that reside on top of varve deposits. As previously concluded, there is little vertical continuity between deep and perched aquifers in the glacial lake sediment environment.