Precambrian geology and geochronology of Minnesota, Bulletin 41, Plate 1
Description:
Interpretations of bedrock geology (distribution of rock at the land surface and beneath surface sediments) of northeastern Minnesota, scale 1 inch = about 15 miles.
Creator:
Baadsgaard, Halfdan, Goldich, Samuel S., 1909-, Hoffman, J. H. (John H.), Krueger, Harold W., and Nier, Alfred O. (Alfred Otto), 1911-1994