1. Geologic Units (Lines): Geology of the Conterminous United States, 2005
2005. King, Philip B., Arndt, Raymond E., Schruben, Paul G., Bawiec, Walter J., and Beikman, Helen M. This line shapefile shows the outlines of geologic units within the United States. This layer is part of the Geologic Map of the United States, ori... Geological Survey (U.S.).