Prism GeoImaging, Inc., Fishers, IN 46038, [email protected]
Advancements in instrumentation and data processing technologies in recent years have significantly increased the role of geophysical methodologies in geologic site characterization projects. The spectrum of projects which benefit from these advances include environmental source and contaminant transport investigations, aquifer exploration and wellfield characterization studies, geotechnical site characterization, aggregate and industrial mineral exploration, and other geologic research studies requiring insitu visualization of unconsolidated and consolidated formations.
One of the most promising methods applied is twodimensional resistivity imaging. This technology appears to be well suited to the types of soil conditions found in the upper Midwest, where silty clay soils are prevalent in many areas. These soils, which are relatively electrically conductive, promote the passage of galvanic electrical currents into the subsurface and into deeper strata.
Continued amassing of resistivity imaging data has begun to better reveal the true nature of both Pleistocene glacial sequences and much older Paleozoic bedrock. Examples of various setting are presented to give the audience a new appreciation for the complexities which until recently were not apparent through widely spaced drilling and very limited exposures in quarries and road cuts.
AAPG Search and Discovery Article #90095©2009 AAPG Eastern Section Meeting, Evansville, Indiana, September 20-22, 2009