|Geologic age||Late Archean|
Metamorphic > Schist > Quartz-feldspar-schistQuartz-plagioclase-biotite schist
Metamorphic > GneissQuartz-plagioclase-biotite schist
|Comments||Continental margin assemblage (north of Niagara Fault). Note that on original map (Sims, 1992), this unit's map symbol was "Wbs". This was shortened to "Ws" in digital version (Cannon et al, 1997) and that convention is followed here. Unit description above is from Sims (1992) for the unit labeled "Wbs".|
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.
Cannon, W.F., Kress, T.H., Sutphin, D.M., Morey, G.B., Meints, Joyce, and Barber-Delach, Robert, 1997, Digital Geologic Map and mineral deposits of the Lake Superior Region, Minnesota, Wisconsin, Michigan: USGS Open-File Report 97-455 (version 3, Nov. 1999).