A distinctive, cherty marine limestone occurring about 35 ft above the Delwood Coal Bed in southern IL, here named Mitchellsville Limestone Bed of the Spoon Formation. Mapped in the northern part of the Eddyville, and the southern part of the Harrisburg and Rudement quads. Strata previously referred to the Curlew Limestone by Butts (1925) and Weller (1940). Palynological study confirms that this limestone is younger than the type Curlew at Indian Hill, Union Co., western KY. Fresh samples are medium to light gray or brownish gray. Limestone is sublithographic to fine grained and contains numerous crinoid fragments, corals, whole brachiopods, and other fossils. Contains abundant nodular chert. Thickness of Mitchellsville 5 ft at type section. Directly underlies the golden sandstone. Age is early Desmoinesian according the Douglass (1987).

Source: GNU records (USGS DDS-6; Reston GNULEX).