South Dakota mafic intrusions

Region Central, North Central
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Mafic intrusive rocks are present in southeastern South Dakota and northern Nebraska; some maybe related to the 1.1 Ga Midcontinent Rift System, but others may not be; at least 1 layered intrusion identified. Focus area includes Corson diabase.
Identified resources Unknown.
Production Unknown.
Status Sporadic exploration in the 1960s and 2000s.
Estimated resources Unknown.
Geologic maps Rocks of interest are fully concealed by younger rocks.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Mafic intrusive rocks are present, at least some known to be related to Midcontinent Rift, and at least one layered intrusion may be present. Located along the Spirit Lake tectonic zone.
Deposits No data.
Evidence from mineral occurrences No data.
Geochemical evidence Need to follow up on borehole information.
Geophysical evidence No data.
Evidence from other sources No data.
Cover thickness and description Covered by <300 m of Paleozoic sedimentary rocks.
Authors Benjamin J. Drenth, Darren J. Johnson.
New data needs New mapping, high resolution geophysics.
Geologic mapping and modeling needs Basement geologic map needed.
Geophysical survey and modeling needs Need Rank 1 aeromagnetic data and gravity data.
Digital elevation data needs Lidar adequate for most or focus area, other area incomplete, but not needed (concealed).