| Basis for focus area |
Mafic, ultramafic, and mixed phase sanukatoid-type intrusions (locally with mafic-ultramafic inclusions) in Minnesota, Wisconsin, Iowa, and Michigan that have plausible potential for magmatic sulfide and/or oxide mineralization. |
| Identified resources |
Unknown. |
| Production |
Unknown. |
| Status |
Unknown. |
| Estimated resources |
No data. |
| Geologic maps |
Jirsa and others (2012), scale 1:500,000; Reed and Daniels (1987), scale 1:500.000; Mudrey and others (1982), scale 1:100,000; Anderson (2006), scale 1:1,000,000. |
| Geophysical data |
Adequate to inadequate Rank 2 to 4 aeromagnetic coverage and inadequate aeroradiometric coverage. |
| Favorable rocks and structures |
Various types of mafic-ultramafic and multi-phase sanukatoid intrusions. |
| Deposits |
No data. |
| Evidence from mineral occurrences |
No data. |
| Geochemical evidence |
Highly variable; see Jirsa and others (2006). |
| Geophysical evidence |
Variable. |
| Evidence from other sources |
Variable. |
| Comments |
The GIS polygon for Minnesota is based on Jirsa and others (2006) with modifications based on subsequent published county atlas maps and the statewide geologic map (Jirsa and others, 2012, S-21). |
| Cover thickness and description |
Locally exposed but commonly covered with up to 200-300 meters of unconsolidated Quaternary sediment and local poorly consolidated Cretaceous sedimentary rocks. |
| Authors |
Benjamin J. Drenth, George Hudak, David Dahl, Amy Block. |
| New data needs |
Geological mapping with associated petrographic, geochemical, geochronological studies and subsurface investigations (drilling). Geophysical studies include bedrock topography (passive seismic) and detailed infill gravity. |
| Geologic mapping and modeling needs |
Geochemical analysis subsurface vein and deposit model. |
| Geophysical survey and modeling needs |
Magnetic survey to determine underlying basement control on sedimentary cover mineralization. |
| Digital elevation data needs |
Lidar variable; adequate, inadequate, and in progress. |
