Migmatitic gneiss and amphibolite (Late to Early Archean) (MIAgn;0)

State	Michigan
Name	Migmatitic gneiss and amphibolite (Late to Early Archean)
Geologic age	Archean
Original map label	Agn
Comments	continental margin assemblage (north of Niagara Fault)
Primary rock type	gneiss
Secondary rock type	migmatite
Other rock types	amphibolite
Lithologic constituents	Major Metamorphic > MigmatiteVaried gneisses of mostly unknown age in cores of gneiss domes and fault-bounded uplifts (Archean gneiss terranes). Except for the Watersmeet dome (Late to Early Archean); all dated rocks are Late Archean. Includes granite of Late Archean age that transgresses gneisses and amphibolite. Metamorphic > AmphiboliteVaried gneisses of mostly unknown age in cores of gneiss domes and fault-bounded uplifts (Archean gneiss terranes). Except for the Watersmeet dome (Late to Early Archean); all dated rocks are Late Archean. Includes granite of Late Archean age that transgresses gneisses and amphibolite. Metamorphic > GneissVaried gneisses of mostly unknown age in cores of gneiss domes and fault-bounded uplifts (Archean gneiss terranes). Except for the Watersmeet dome (Late to Early Archean); all dated rocks are Late Archean. Includes granite of Late Archean age that transgresses gneisses and amphibolite.
Map references	Sims, P.K., 1992, Geologic map of Precambrian rocks, southern Lake Superior region, Wisconsin and northern Michigan: U.S. Geological Survey Miscellaneous Investigations Map I-2185, scale= 1:500,000 [http://pubs.er.usgs.gov/publication/i2185]
Unit references	Sims, P.K., 1992, Geologic map of Precambrian rocks, southern Lake Superior region, Wisconsin and northern Michigan: U.S. Geological Survey Miscellaneous Investigations Map I-2185, scale= 1:500,000 [http://pubs.er.usgs.gov/publication/i2185]
Geographic coverage	Baraga - Dickinson - Gogebic - Iron - Marquette