GIS-BASED DELINEATION OF A BURIED BEDROCK VALLEY IN EAST-CENTRAL WISCONSIN
WCR data were acquired for twelve counties in east-central Wisconsin; within this area, over 75,000 well records were collected. The WCR data were processed to verify that all records were accurately geolocated, ensuring that each record was associated with an accurate ground-surface elevation. Records that could not be accurately located were removed from the analysis. The WCR data were then filtered to remove well records that did not provide useful information about depth to the buried bedrock surface, and further processed to remove closely-spaced, redundant records. This resulted in approximately 16,000 well records that were used to resolve bedrock topography. These verified points were processed with an ArcMap raster interpolation tool to identify the location and trend of the buried bedrock valley, as well as the higher bedrock surfaces on either side of the buried valley.
The bedrock topography defined by this work refines evidence presented by Stewart (1973) for a deep, buried channel extending northeast from the Sauk City area through Marinette County. The location and gradient of this buried valley is consistent with it being a downstream continuation of the east-flowing river identified in southwestern Wisconsin.