Geologic units in Wayne county, Missouri

Roubidoux Formation (Early Ordovician-Ibexian Series) at surface, covers 43 % of this area

Sandstone, chert and interbedded dolomite

Gasconade Dolomite (Early Ordovician-Ibexian Series) at surface, covers 25 % of this area

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

Eminence Dolomite, Potosi Dolomite (Late Cambrian-Croixian Series) at surface, covers 24 % of this area

Eminence Dolomite - dolomite with some druse - coated chert. Potosi Dolomite - dolomite with abundance of druse - coated chert.

St. Francois Mountains intrusive suite (subvolcanic, alkali granitic ring complexes) (Precambrian Y) at surface, covers 2 % of this area

St. Francois Mountains intrusive suite (subvolcanic, alkali granitic ring complexes).

Holocene series (Quaternary-Holocene Series) at surface, covers 2 % of this area

Alluvium - clay, silt, sand, and gravel.

St. Francois mountains volcanic supergroup (Precambrian Y) at surface, covers 1 % of this area

Chiefly alkali rhyolitic ash - flow tuffs, lava flows, and bedded tuffs, with minor trachytes.

Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (Early Ordovician-Ibexian Series) at surface, covers 1 % of this area

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

Elvins Group - (including Derby-Doerun Dolomite, Davis Formation), Bonneterre Dolomite (Late Cambrian-Croixian Series) at surface, covers < 0.1 % of this area

Derby-Doerun Dolomite - alternating thin dolomite, siltstone, and shale; Davis Formation - glauconitic shale with fine - grained sandstone, limestone, and dolomite); Bonneterre Dolomite - dolomite, dolomitic limestone, and limestone; glauconitic in lower part.