State | Minnesota |
---|---|
Name | Mille Lacs and North Range Groups and equivalent sedimentary rocks |
Geologic age | Paleoproterozoic |
Lithologic constituents |
Major
Sedimentary > Clastic > Sandstone > Graywacke (Bed)sandstone and graywacke
Sedimentary > Clastic > Siltstone (Bed)
Metamorphic > Metasedimentary > Metaclastic > Slateargillite to slate
Minor
Sedimentary > Chemical > Banded-iron-formation (Bed, Carbonaceous)carbonate- and sulfide-facies iron-formation and allied anomalously iron-rich sedimentary rocks
Incidental
Metamorphic > Metasedimentary > Metacarbonate > MarbleTrout Lake marble of Mille Lacs Group
|
Comments | Part of the Mille Lacs and North Range Groups in the fold-and-thrust belt of the Penokean orogen (twice-deformed). Twice-deformed metasedimentary rocks at the apparent base of the Animikie basin. Part of the Geon 18 intrusions and supracrustal rocks (syn- to late Penokean orogenesis). |
References | Jirsa, Mark A., Boerboom, Terrence J., Chandler, Val W., Mossler, John H., Runkel, Anthony C., and Setterholm, Dale R., 2011, S-21 Geologic Map of Minnesota-Bedrock Geology; Minnesota Geological Survey, State Map Series S-21. Scale 1:500,000.USGS Geologic Names lexicon found at: http://ngmdb.usgs.gov/Geolex/https://ngmdb.usgs.gov/Geolex/search |
NGMDB product | |
Counties | Aitkin - Benton - Carlton - Cass - Crow Wing - Mille Lacs - Morrison - Sherburne - Todd |