Upper Pennsylvanian Compression Floras of the 7-11 Mine, Columbiana County, Northeastern Ohio

Author Institution: Department of Botany, Ohio UniversityTwo compression floras have been discovered below the Brush Creek marine unit (lower Conemaugh) in Columbiana County, Ohio. One flora is preserved in freshwater ironstone beds 6 m below the Brush Creek and contains abundant pteridosperm and sphenopsid elements. The assemblage includes Sphenophyllum oblongifolium, Pecopteris candolleana, Danaeites emersonii and Odontopteris brardii, taxa previously recorded from younger strata. The second assemblage occurs within a 1.5-m-thick argillaceous, freshwater shale directly below the Brush Creek and yields abundant lycopod, cordaite, and conifer remains. The latter elements, some of which are permineralized with pyrite, represent the earliest occurrence of conifers in the eastern United States known to date