Geologic units in Perry county, Missouri

Decorah Group, Plattin Group (Middle Ordovician-Mohawkian Series) at surface, covers 30 % of this area

Decorah Group, Plattin Group

Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (Early Ordovician-Ibexian Series) at surface, covers 18 % of this area

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

Holocene series (Quaternary-Holocene Series) at surface, covers 13 % of this area

Alluvium - clay, silt, sand, and gravel.

Joachim Dolomite, Dutchtown Formation (Middle Ordovician-Mohawkian Series) at surface, covers 11 % of this area

Joachim Dolomite, Dutchtown Formation

St. Peter Sandstone, Everton Formation (Middle Ordovician to Early Ordovician) at surface, covers 10 % of this area

St. Peter Sandstone, Everton Formation

Roubidoux Formation (Early Ordovician-Ibexian Series) at surface, covers 7 % of this area

Sandstone, chert and interbedded dolomite

Chesterian Series (Late Mississippian-Chesterian Series) at surface, covers 4 % of this area

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.

Devonian System (Late to Early Devonian) at surface, covers 3 % 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.

Leemon Formation, Maquoketa Group, Cape Limestone, Kimmswick Limestone, Noix-Cyrene Limestone, Maquoketa Shale (Late Ordovician to Middle Ordovician) at surface, covers 1 % 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.

Gasconade Dolomite (Early Ordovician-Ibexian Series) at surface, covers 1 % of this area

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

Silurian system (Late Silurian- to Early Silurian) at surface, covers 0.9 % of this area

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

Meramecian Series (Late Mississippian-Meramecian Series) at surface, covers 0.5 % of this area

St. Louis Limestone, Salem Formation, Warsaw Formation.

Osagean Series (Early Mississippian-Osagean Series) at surface, covers 0.1 % of this area

Keokuk Limestone, Burlington Limestone, Elsey Formation, Reeds Spring Formation, Pierson Limestone, Fern Glen Formation.

Lower Pope Group (Aux Vases Sandstone through Glen Dean Limestone) (Mississippian (Visean)) at surface, covers < 0.1 % of this area

Lower Pope Group (Aux Vases Sandstone through Glen Dean Limestone).

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.

Muscatatuck Group (Middle Devonian (Eifelian to Givetian)) at surface, covers < 0.1 % of this area

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) (Mississippian (Serpukhovian)) at surface, covers < 0.1 % of this area

Upper Pope Group (Tar Springs Sandstone through Kinkaid Limestone).

Warsaw Formation and Salem Limestone (Mississippian (Visean)) at surface, covers < 0.1 % of this area

Warsaw Formation and Salem Limestone in western Illinois.

St. Louis Limestone (Mississippian (Visean)) at surface, covers < 0.1 % of this area

St. Louis Limestone.