Cretaceous weathering of Archean and Paleoproterozoic rocks

Region Central, North Central
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

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.