Exploration for a Buried Valley by Resistivity and Thermal Probe Surveys

Abstract

ABSTRACTElectrical resistivity and thermal probe surveys were conducted in the vicinity of Morning Sun, Ohio, in an attempt to locate a buried glacial valley.The resistivity survey along six roughly parallel traverse lines was able to distinguish buried valley gravel from glacial till and Upper Ordovician limestone bedrock. A relative depth to bedrock contour map drawn from the resistivity data reveals two buried valleys east of Morning Sun, which coalesce under Morning Sun, then continue as one valley to its junction with the Four Mile Creek buried valley at the northeast corner of Acton Lake. The field data yield only a proposed location of the buried valley since test holes were not drilled for confirmation.The thermal probe, an electronic thermometer utilizing a thermistor at the end of an aluminum‐tipped probe and a transistor‐amplified bridge circuit, was employed in measuring near‐surface temperatures at 4‐foot depths along the same 6 traverse lines made in the resistivity survey. The thermal probe survey was unable to distinguish a summer low‐temperature anomaly trend, indicative of a buried valley. The depth of the buried valley under the till overburden is 90 to 150 feet which is too deep to contact the summer segment of the annual wave; therefore, a near‐surface low‐temperature anomaly is not produced.