Puritan Quartz Monzonite

Pink to pinkish-gray, medium- to coarse-grained, equigranular to inequigranular granite to granodiorite in Puritan batholith south of Gogebic Range. Age 2710 +/- 140 Ma (Sims and others, 1977)
State Wisconsin
Name Puritan Quartz Monzonite
Geologic age Late Archean
Lithologic constituents
Igneous > Plutonic > Granitic > Granodiorite
Igneous > Plutonic > Granitic > Granite
Comments Continental margin assemblage (north of Niagara Fault)

Sims and others, 1977, Geology and Rb-Sr age of Precambrian W Puritan Quartz Monzonite, northern Michigan: U.S. Geological Survey Journal of Research, v. 5, p. 185-192.

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.


NGMDB product
Counties Ashland - Iron