ABSTRACTA detailed gravity survey of 295 points was conducted in Brimfield Township, Ohio to map buried bedrock topography with a higher degree of resolution than was possible by well data alone. The survey included a subset of 40 stations where both gravity and bedrock depth were determined. Partial correlation analysis allowed identification of a regional gravity trend, and multiple linear regression led to quantitative estimates of depth to bedrock throughout the surveyed area in a manner different from the standard method of gravity interpretation that employs models of different shapes, sizes, and density contrasts. Glacial sediments range in thickness from 10 to 150 feet, with the thickest portions generally over the axis of the buried valley. Some variations in predicted versus measured bedrock depth may be a function of variation in density of the glacial sediments or of topographic effects of the buried bedrock surface. The results of the analysis led to an improved estimate for the bedrock elevation and thickness of valley fill. The interpretation has implications with regard to the volume of glacial sediments in the area and their potential productivity as sources of ground water in the future.
展开▼
