Named as basal member of Floris Formation of Cherokee Group of Des Moines Supergroup. Name derived from name of an abandoned mining town. Type section is in stream cut on Soap Creek, SE1/4, SE1/4, NW1/4, sec 17, T70N, R12W, Davis Co, IA on the Iowa shelf. Consists of 4 coals at its type that total 8.6 ft thick and are separated by beds of dark gray shale, gray silty mudstone, and two thin gray, fossiliferous limestones that are collectively 27+ ft thick. Coal beds present at base and at top of member. Measured section. Cross section. Nomenclature chart. Has more coals in other sections. Known in subsurface of Wapello and Monroe Cos, IA on the Iowa shelf. Overlies Kalo Formation (new) of Cherokee Group. Underlies unnamed part of Floris Formation. Of Pennsylvanian, Desmoinesian age.

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