Geologic units in Watonwan county, Minnesota

Upper Cambrian, undivided (Late Cambrian) at surface, covers 2 % of this area: Upper Cambrian, undivided - Jordan Sandstone; dolomite, glauconite, and silty glauconite rocks of the St. Lawerence and Franconia Formation; Ironton and Galesville Sandstones; sandy and shaly rocks of the Eau Claire Formation; and the Mt. Simon Sandstone.
Lithology: dolostone (dolomite); sandstone; shale
Sioux Quartzite (Early Proterozoic) at surface, covers 19 % of this area: Sioux Quartzite - Red quartzite of fluvial to possibly marginally marine origin. Includes quartz-pebble conglomerate, claystone (catlinite, also called pipestone), a basal (rhyolite) pebble conglomerate in Pipestone County, and a basal (granite, quartz, chert, iron-formation) conglomerate in Nicollet County on the Minnesota River
Lithology: quartzite; conglomerate; claystone
Cretaceous rocks, undivided (Cretaceous) at surface, covers 79 % of this area: Cretaceous rocks, undivided - Dakota, Graneros, Greenhorn, Carlie, Niobara, and Pierre formations and their nonmarine equivalents in northwestern, southwestern, and southeastern Minnesota
Lithology: shale; sandstone; limestone