20240112 08342100 1.0 TRUE Bedrock Geology The map depicts bedrock geologic units exposed and covered by glacial sediment in Renville County. The interpretation relies on previously published and unpublished geologic mapping, augmented with high-resolution geophysical data and field work by the authors. The bedrock ranges in age from Paleoarchean (3600-3200 Ma, or million years old) to Late Cretaceous (~90 Ma), and records a complex history involving multiple igneous, sedimentary, metamorphic, and tectonic events, as well as significant episodes of weathering and erosion. Mark A. Jirsa, Dale R. Setterholm, and V.W. Chandler