Lower Pope Group (Aux Vases Sandstone through Glen Dean Limestone).
Upper Pope Group (Tar Springs Sandstone through Kinkaid Limestone).
Shelburn-Patoka Formations undivided.
St. Louis Limestone.
Warsaw Formation and Salem Limestone in western Illinois.
Meppen Limestone, Fern Glen Formation, and Burlington-Keokuk Limestone.
Alluvium - clay, silt, sand, and gravel.
Kimmswick (Trenton) Limestone and Decorah Formation in southern and western Illinois.
Ste. Genevieve Limestone.