Bgoc83

The Bgoc83 file contains information created by the Minnesota Geological Survey about the location, shape, and type of Precambrian bedrock outcrop in the upper Minnesota River valley from the mouth of Sacred Heart Creek in Renville County westward to Ortonville. Setterholm created the polygons for the outcrops (see Setterholm, 1998). The outcrops were mapped in the field on 1:24,000 scale topographic maps. The outcrop boundaries were digitized from the field maps. The data was transformed to NAD83 datum by the DNR. In the northern tip of Redwood County, where there is overlapping bedrock outcrop data from this reference and the Bdrkpy file, the polygons from this file are presented on Plate III. [Compiler’s note: floods change the landscape over time by uncovering some bedrock outcrops and covering others.] The source of this information is:

Setterholm, D.R., 1998, Depth to Bedrock and Glacial Drift Thickness for the Minnesota River Valley Corridor Database Development and Mapping Project; Minnesota Geological Survey [Arc/Info Coverages; The data source for Precambrian bedrock outcrops was Minnesota Geological Survey Regional Hydrologic Assessment 4, Part A, Quaternary geology- upper Minnesota River basin, Minnesota; C.J. Patterson, project manager, 1999. Scale 1:200,000.]