Powder Mill Group; Siemens Creek Volcanics (WIYs;0)

State	Wisconsin
Name	Powder Mill Group; Siemens Creek Volcanics
Geologic age	Middle Proterozoic
Lithologic constituents	Major Igneous > Volcanic > Mafic-volcanic > Basalt (Flow) Incidental Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)
Comments	This unit is labeled ""Ysb"" on the paper map of Sims (1992) and ""Ys"" in Cannon and others (1997). Unit description is from the unit labeled ""Ysb"" from Sims (1992).
References	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), scale 1:500,000. https://pubs.er.usgs.gov/publication/ofr97455 Davis, D.W., and Green, J.C., 1997, Geochronology of the North American Midcontinent rift in western Lake Superior and implications for its geodynamic evolution: Canadian Journal of Earth Sciences, v. 34, pp. 476-488. 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. https://pubs.er.usgs.gov/publication/i2185
NGMDB product	NGMDB product page for 10177 NGMDB product page for 49339
Counties	Ashland - Iron

State

Wisconsin

Name

Powder Mill Group; Siemens Creek Volcanics

Geologic age

Middle Proterozoic

Lithologic constituents

Major

Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)

Incidental

Igneous > Volcanic > Mafic-volcanic > Andesite (Flow)

Comments

This unit is labeled ""Ysb"" on the paper map of Sims (1992) and ""Ys"" in Cannon and others (1997). Unit description is from the unit labeled ""Ysb"" from Sims (1992).

References

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), scale 1:500,000.

https://pubs.er.usgs.gov/publication/ofr97455

Davis, D.W., and Green, J.C., 1997, Geochronology of the North American Midcontinent rift in western Lake Superior and implications for its geodynamic evolution: Canadian Journal of Earth Sciences, v. 34, pp. 476-488.

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.

https://pubs.er.usgs.gov/publication/i2185

NGMDB product

NGMDB product page for 10177

NGMDB product page for 49339

Counties

Ashland - Iron