Anderson, S. (Geologist)Chandler, Val W.Nordstrand, E.Aeromagnetic anomaly map, (relative to the earth's magnetic field, interpretation of magnetic data collected from airborne surveys, the map colors indicate the distribution and concentration of magnetic minerals (primarily iron-bearing) within the upper crust of the earth, shaded-relief (psuedo 3d), northeastern and east-central Minnesota, scale 1:1,000,000.PDFengMinnesota Geological SurveyPublicShaded relief aeromagnetic anomaly map of northeastern and east-central Minnesota, M-53MapsMinnesota1984University of Minnesota