Decorah Group, Plattin Group
Fine crystalline, silty, cherty dolomite, and oolitic chert with local sandstone beds.
Alluvium - clay, silt, sand, and gravel.
Joachim Dolomite, Dutchtown Formation
St. Peter Sandstone, Everton Formation
Sandstone, chert and interbedded dolomite
Fayetteville Formation, Batesville Formation, Hindville Limestone, Vienna Limestone, Tar Springs Sandstone, Glen Dean Formation, Hardinsburg Formation, Golconda Formation, Cypress Formation, Paint Creek Formation, Yankeetown Sandstone, Renault Formation, Aux Vases Sandstone, Ste. Genevieve Limestone.
Chattanooga Shale, Sylamore Sandstone, Fortune Formation, Holts Summit Sandstone, Snyder Creek Shale, Cedar Valley Limestone, Louisiana Limestone, Saverton Shale, Grassy Creek Shale, Turpin Sandstone, Bushberg Sandstone, Glen Park Limestone, St. Larent Limestone, Beauvais Sandstone, Grand Tower Limestone, Clear Creek Chert, Little Saline Limestone, Grassy Knob Chert, Bailey Formation.
Leemon Formation, Maquoketa Group including: (Girardeau Limestone, Orchard Creek Shale, Thebes Sandstone, Cape La Croix Shale), Cape Limestone, Kimmswick Limestone, Noix-Cyrene Limestone, Maquoketa Shale.
Coarse - crystalline cherty dolomite with a basal Gunter Sandstone Member.
Joliet Limestone, Bowling Green Dolomite, Bryant Knob Formation, Bainbridge Formation, Sexton Creek Limestone.
St. Louis Limestone, Salem Formation, Warsaw Formation.
Keokuk Limestone, Burlington Limestone, Elsey Formation, Reeds Spring Formation, Pierson Limestone, Fern Glen Formation.
Lower Pope Group (Aux Vases Sandstone through Glen Dean Limestone).
Tamms Group, includes Bailey Limestone, “Flat Gap Limestone”, Grassy Knob Chert, Backbone Limestone, and Clear Creek Formation.
Muscatatuck Group, includes Grand Tower Limestone and St. Laurent (Alto and Lingle) Formation in southern Illinois; includes Detroit River Formation, Wapsipinicon Limestone, and Cedar Valley Limestone in northern and western Illinois.
Upper Pope Group (Tar Springs Sandstone through Kinkaid Limestone).
Warsaw Formation and Salem Limestone in western Illinois.
St. Louis Limestone.