Neoarchean Greenstone Belts of Minnesota, North Dakota and South Dakota

Region Central, North Central
Mineral systems
Deposit types
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Geophysical anomalies and limited borehole data indicate the existence of these greenstone belts of the Wabigoon subprovince concealed under Paleozoic cover. Archean greenstone belts in general are permissive for these deposit types.
Identified resources No data.
Production No known production.
Status Possible past exploration.
Estimated resources No data.
Geologic maps Sims and others (1991), scale 1:1,000,000.
Geophysical data Inadequate Rank 5 aeromagnetic data with poor ground gravity coverage in central and western North and South Dakota. Inadequate Rank 3 aeromagnetic data in coverage areas of northern and southern Minnesota. Inadequate aeroradiometric coverage.
Favorable rocks and structures Archean greenstone belts.
Deposits None.
Evidence from mineral occurrences No data (concealed).
Geochemical evidence No data.
Geophysical evidence Aeromagnetic and ground gravity anomalies.
Evidence from other sources Limited borehole information.
Comments Defined on the basis of generally very poor geophysical data and limited borehole info; a primary goal should be systematic coverage with modern, high-quality geophysics.
Cover thickness and description Total cover is variable from 0 to 1000 feet; The most common overburden is Quaternary glacial sediment (till) which can range from 0-over 500 feet thick. Patchy Mesozoic (Cretaceous) and Paleozoic strata up to ~300 feet thick are locally present beneath glacial sediments. Locally saprolite of several tens of feet covers solid Precambrian bedrock.
Authors Benjamin J. Drenth, Amy Block.
New data needs Complete Rank 1 aeromagnetic coverage, ground gravity coverage, basement mapping.
Geologic mapping and modeling needs Improved basement map.
Geophysical survey and modeling needs Rank 1 aeromagnetic coverage, ground gravity coverage.
Digital elevation data needs Lidar adequate, but not needed (concealed).