Geologic units in Shawano county, Wisconsin

Wolf River batholith; Wolf River Granite (Middle Proterozoic) at surface, covers 34 % of this area

Red, coarse-grained rapakivi granite consisting of large (1-3 cm) ovoid alkali feldspar sporadically mantled by plagioclase, interstitial plagioclase, quartz, biotite, hornblende, and ilmenite

Cambrian, undivided (Cambrian) at surface, covers 25 % of this area

Sandstone with some dolomite and shale, undivided; includes Trempealeau, Tunnel City, and Elk Mound Formations

Wolf River batholith; Red River Granite (Middle Proterozoic) at surface, covers 15 % of this area

Contains alkali feldspar phenocrysts (0.5-2 cm), subordinate plagioclase and quartz, and rare clusters of biotite with or without hornblende

Prairie du Chien Group (Ordovician) at surface, covers 11 % of this area

Dolomite with some sandstone and shale; includes Shakopee and Oneota Formations

Wolf River Batholith; Anorthosite (Middle Proterozoic) at surface, covers 10 % of this area

Gray, coarse-grained (1-20 cm) plagioclase-rich (An45-53) rock containing interstitial orthopyroxene, clinopyroxene, Fe-Ti oxides, and apatite.

Sinnipee Group (Ordovician) at surface, covers 3 % of this area

Dolomite with some limestone and shale; includes Galena, Decorah, and Platteville Formations

Ancell Group (Ordovician) at surface, covers 1 % of this area

Orthoquartzitic sandstone with minor limestone, shale and conglomerate; includes Glenwood and St. Peter Formations