Geologic units in Polk county, Missouri

Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (Early Ordovician-Ibexian Series) at surface, covers 57 % of this area

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

Osagean Series (Early Mississippian-Osagean Series) at surface, covers 24 % of this area

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

Kinderhookian Series (Early Mississippian-Kinderhookian Series) at surface, covers 16 % of this area

Northview Shale, Sedalia Formation, Compton Limestone, Bachelor Formation Chouteau Group, Hannibal Shale, Horton Creek Limestone.

Riverton Formation, Burgner Formation (Middle Pennsylvanian-Atokan Stage) at surface, covers 2 % of this area

Shale, clay, coal. Burgner Formation - limestone.

Channel Sandstones (Pennsylvanian) at surface, covers 1 % of this area

Channel Sandstones

Meramecian Series (Late Mississippian-Meramecian Series) at surface, covers < 0.1 % of this area

St. Louis Limestone, Salem Formation, Warsaw Formation.