Geologic units in Outagamie county, Wisconsin

Sinnipee Group (Ordovician) at surface, covers 37 % of this area

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

Cambrian, undivided (Cambrian) at surface, covers 37 % of this area

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

Prairie du Chien Group (Ordovician) at surface, covers 19 % of this area

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

Ancell Group (Ordovician) at surface, covers 5 % of this area

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

Wolf River batholith; Waupaca Granite (Middle Proterozoic) at surface, covers 2 % of this area

Rapakivi granite (wiborgite) containing 70-80 percent coarse (1.5 -5 cm) ovoid alkali feldspars mantled by plagioclase, coarse anhedral quartz, and interstitial hornblende and biotite

Maquoketa Formation (Ordovician) at surface, covers < 0.1 % of this area

Shale, dolomitic shale and dolomite; includes overlying Neda Formation (age uncertain) consisting of oolitic iron oxides and shale