Middle Keweenawan Basin Evolution Inferred from Geophysical Analysis of Strongly Magnetic Intrusion, Clam Lake, Wisconsin Open-file report; contains unpublished data that has not yet been peer-reviewed. Bedrock Geology Geophysics Data and Resources WOFR2003-04 Middle Keweenawan Basin Evolution Inferred from Geophysical Analysis of a Strongly Magnetic Intrusion, Clam Lake, Wisconsin Mudrey, M.G., Jr.; Ervin, C.P.; Olmstead, J.F.; 2003 Report: 17 p. Download Related Collections Open-File Report View Open-File Report