| Basis for focus area |
Focus area includes in situ regolith deposits resting on Archean/Paleoproterozoic granitic source rocks. |
| Identified resources |
Unknown. |
| Production |
Unknown. |
| Status |
Unknown. |
| Estimated resources |
Unknown. |
| Geologic maps |
Jirsa and others (2012), scale 1: 500,000. |
| Geophysical data |
Adequate aeromagnetic coverage; inadequate aeroradiometric coverage. |
| Favorable rocks and structures |
Areas of deep weathering with development of in situ thick regolith over Precambrian rocks, typically preserved under remnants of Cretaceous rocks. |
| Deposits |
No data. |
| Evidence from mineral occurrences |
No data available. |
| Geochemical evidence |
Potential for chemically extractable REE. |
| Geophysical evidence |
No data. |
| Evidence from other sources |
In-situ regolith development during Jurassic/Cretaceous-preserved under Cretaceous cover. |
| Cover thickness and description |
Cretaceous rocks are more or less continuous beneath glacial cover through the western half of Minnesota and form numerous outliers in the eastern half. Exposures are sparse. |
| Authors |
Laurel G. Woodruff. |
| New data needs |
New mapping. |
| Geologic mapping and modeling needs |
Surficial mapping at 1:24:000 scale. |
| Geophysical survey and modeling needs |
None. |
| Digital elevation data needs |
Lidar inadequate. |
