Named as the upper named member (of 3) of Floris Formation (new) one of four formations of Cherokee Group of "Des Moines Supergroup" for Carruthers Creek, northeastern Lucas Co, IA on the Iowa shelf. Type section is a road cut in NW1/4, NW1/4, SE1/4, sec 3, T73N, R20W where it has a basal shaly pyritic coal 1.4 ft thick overlain by dark gray, fossiliferous (lingulid brachiopods, pelecypods) clay shale 1.4 ft thick succeeded by 1) 6 ft of gray to maroon shale with orange brown to maroon ironstone, 2) dark gray shale with phosphate nodules 0.5 ft thick, 3) 10.8 ft of gray silty mudstone and brown very fine grained sandstone and interbedded siltstone, and 4) 0.5 ft of persistent smut. Overlies unnamed shale of Floris. Underlies unnamed sandstone of Floris. Cross sections. Shown as present also in Guthrie, Marion, Warren, Monroe and Wapello Cos, IA on the Iowa shelf. Nomenclature chart. Of Desmoinesian, Pennsylvanian age.

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