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Federal
Tertiary dikes in the Southern Piceance Basin, Colorado (psintrg)
Department of the Interior —
Tertiary dikes in the southern Piceance Basin. -
Federal
Exposed Precambrian Bedrock in Part of Dickinson County, Michigan, and Marinette and Florence Counties, Wisconsin
Department of the Interior —
The U.S. Geological Survey conducted a program of bedrock geologic mapping in much of the central and western upper peninsula of Michigan and parts of Wisconsin from...