Geologic units in Cape Girardeau county, Missouri

St. Peter Sandstone, Everton Formation (Middle Ordovician to Early Ordovician) at surface, covers 17 % of this area

St. Peter Sandstone, Everton Formation

Decorah Group, Plattin Group (Middle Ordovician-Mohawkian Series) at surface, covers 17 % of this area

Decorah Group, Plattin Group

Holocene series (Quaternary-Holocene Series) at surface, covers 16 % of this area

Alluvium - clay, silt, sand, and gravel.

Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (Early Ordovician-Ibexian Series) at surface, covers 13 % of this area

Fine crystalline, silty, cherty dolomite, and oolitic chert with local sandstone beds.

Devonian System (Late to Early Devonian) at surface, covers 13 % of this area

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.

Joachim Dolomite, Dutchtown Formation (Middle Ordovician-Mohawkian Series) at surface, covers 10 % of this area

Joachim Dolomite, Dutchtown Formation

Leemon Formation, Maquoketa Group, Cape Limestone, Kimmswick Limestone, Noix-Cyrene Limestone, Maquoketa Shale (Late Ordovician to Middle Ordovician) at surface, covers 8 % of this area

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.

Silurian system (Late Silurian- to Early Silurian) at surface, covers 7 % of this area

Joliet Limestone, Bowling Green Dolomite, Bryant Knob Formation, Bainbridge Formation, Sexton Creek Limestone.

Kimmswick (Trenton) Limestone and Decorah Formation (Upper Ordovician (Stage 6)) at surface, covers < 0.1 % of this area

Kimmswick (Trenton) Limestone and Decorah Formation in southern and western Illinois.

Tamms Group (Upper Silurian (Pridoli) to Lower Devonian (Emsian)) at surface, covers < 0.1 % of this area

Tamms Group, includes Bailey Limestone, “Flat Gap Limestone”, Grassy Knob Chert, Backbone Limestone, and Clear Creek Formation.

Silurian System undivided (Silurian (Llandovery to Pridoli)) at surface, covers < 0.1 % of this area

Silurian System undivided, includes Sexton Creek Limestone, St. Clair Limestone, and Moccasin Springs Formation in southern Illinois; includes Wilhelmi Formation, Elwood Dolomite, Kankakee Dolomite, Joliet Dolomite, Sugar Run Dolomite, and Racine Dolomite in northeastern Illinois; includes Mosalem, Tete des Morts, Blanding, Sweeney, Marcus, and Racine Dolomites in northwestern Illinois.

Maquoketa Formation or Group (Upper Ordovician (Stage 6 to Hirnatian)) at surface, covers < 0.1 % of this area

Maquoketa Formation or Group, includes Cape Limestone, Cape La Croix Shale, Thebes Sandstone, Orchard Creek Shale, Girardeau Limestone, and Leemon Formation in southern Illinois; includes Scales Shale, Fort Atkinson Limestone, Brainard Shale, and Neda Formation in northern Illinois; includes Noix Oolite in western Illinois.

Gasconade Dolomite (Early Ordovician-Ibexian Series) at surface, covers < 0.1 % of this area

Coarse - crystalline cherty dolomite with a basal Gunter Sandstone Member.