Geologic units in Monroe county, Iowa

Cherokee Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moines]) at surface, covers 93 % of this area: Cyclic deposits with carbonaceous shale, clay, siltstone, with lesser sandstone, and thick coal beds; minor but persistent limestone beds; may include parts of Atoka or Morrow Series.
Lithology: shale; claystone; siltstone; sandstone; coal; limestone
Marmaton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Middle [Des Moines]) at surface, covers 4 % of this area: Alternating shale and limestone, with some sandstone and coal; Lenapah FM at top and Fort Scott at base.
Lithology: shale; limestone; sandstone; coal
Meramec Series (Phanerozoic | Paleozoic | Carboniferous Mississippian-Late) at surface, covers 2 % of this area: Ste. Genevieve Limestone- fossiliferous limestone and red and green shale. Approx. thickness 50 ft. St. Louis Limestone- limestone and dolomite, sandstone locally perdominant; locally contains chert. Spergen Formation- sandy micaceous dolomite.
Lithology: limestone; dolostone (dolomite); shale; sandstone; chert
Pleasanton Group (Phanerozoic | Paleozoic | Carboniferous Pennsylvanian-Late [Missouri]) at surface, covers 0.5 % of this area: Shale with some sandstone, thin limestone beds and minor coal; Exline Limestone near top Chariton Conglomerate at base. .
Lithology: shale; sandstone; limestone; coal