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As part of a hydrogeophyscial study of the Vars-Winchester esker three seismic profiles have been acquired using a novel in-house two component (horizontal and vertical) Microvibe seismic source with a 48-channel, three component landstreamer. This new hardware has allowed for the acquisition and processing of very high-resolution 2-D images of the esker for groundwater exploration. Following the acquisition of the profiles, four boreholes have been drilled to bedrock. The lithologies of the esker system such as marine mud (silt and clay), sand, gravel, and diamicton, are well characterised by the seismic facies and shearwave velocities.

A study examining the relationship between hydraulic and geophysical properties is underway in the South Nation Conservation Area, southeast of Ottawa, Ontario. Groundwater resources for the local community are drawn from a sand and gravel esker, which is capped by a thick sequence of post-glacial massive to laminated mud sediment. Surface geophysical techniques (high-resolution seismic and electrical resistivity) identified the depth, shape, and general stratigraphy of the esker within the 2-km study area. Four boreholes were then drilled into the center and flanks of the esker to install fully screened PVC casings to conduct hydraulic packer testing and downhole geophysical logging. The geophysical log suite provided a number of insights into the esker stratigraphy and overlying Champlain Sea mud. Gamma, conductivity, magnetic susceptibility, and density logs refined the depths of lithological boundaries and the nature of these contacts (abrupt vs transitional). Bulk conductivity profiles revealed differences in pore water conductivities in the mud sediments overlying and lateral to the esker. Magnetic susceptibility logs revealed the presence of stratigraphic layering within the esker, which nuclear magnetic resonance (NMR) logs identified as having variable porosity.

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