Chengwatana Volcanic Group (WIYcv;0)

State	Wisconsin
Name	Chengwatana Volcanic Group
Geologic age	Middle Proterozoic
Lithologic constituents	Major Igneous > Volcanic > Mafic-volcanic > Basalt (Flow, Pyroclastic-tuff) Minor Sedimentary > Clastic > Mixed-clastic (Bed)
Comments	This group has U-Pb zircon ages ranging from about 1094.6 +/- 2.1 Ma from a rhyolite near Lake Nelson, WI (Zartman and others, 1997, U-Th-Pb zircon ages of some Keweenawan Supergroup rocks from the south shore of Lake Superior: Canadian Journal of Earth Sciences, v. 34, p. 549-561) to 1100-1102 +/- 5 Ma elsewhere in the unit (G. Garrels, Univ. of Arizona, unpublished data, 2000; M. Schmidt, MIT, unpublished data, 2000).
References	Zartman and others, 1997, U-Th-Pb zircon ages of some Keweenawan Supergroup rocks from the south shore of Lake Superior: Canadian Journal of Earth Sciences, v. 34, p. 549-561. G. Garrels, Univ. of Arizona, unpublished data, 2000. M. Schmidt, MIT, unpublished data, 2000. 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	Bayfield - Burnett - Douglas - Polk - Sawyer - Washburn

State

Wisconsin

Name

Chengwatana Volcanic Group

Geologic age

Middle Proterozoic

Lithologic constituents

Major

Igneous > Volcanic > Mafic-volcanic > Basalt (Flow, Pyroclastic-tuff)

Minor

Sedimentary > Clastic > Mixed-clastic (Bed)

Comments

This group has U-Pb zircon ages ranging from about 1094.6 +/- 2.1 Ma from a rhyolite near Lake Nelson, WI (Zartman and others, 1997, U-Th-Pb zircon ages of some Keweenawan Supergroup rocks from the south shore of Lake Superior: Canadian Journal of Earth Sciences, v. 34, p. 549-561) to 1100-1102 +/- 5 Ma elsewhere in the unit (G. Garrels, Univ. of Arizona, unpublished data, 2000; M. Schmidt, MIT, unpublished data, 2000).

References

Zartman and others, 1997, U-Th-Pb zircon ages of some Keweenawan Supergroup rocks from the south shore of Lake Superior: Canadian Journal of Earth Sciences, v. 34, p. 549-561.

G. Garrels, Univ. of Arizona, unpublished data, 2000.

M. Schmidt, MIT, unpublished data, 2000.

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

Bayfield - Burnett - Douglas - Polk - Sawyer - Washburn