Geologic units in Butler county, Missouri

Holocene series (Quaternary-Holocene Series) at surface, covers 57 % of this area

Alluvium - clay, silt, sand, and gravel.

Roubidoux Formation (Early Ordovician-Ibexian Series) at surface, covers 36 % of this area

Sandstone, chert and interbedded dolomite

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

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

Terrace deposits (Late Pleistocene) at surface, covers 0.2 % of this area

Alluvial deposits on one or more terrace levels

Alluvium - Alluvial deposits of local streams or of overbank flow of major streams (Holocene) at surface, covers < 0.1 % of this area

Alluvial deposits of local streams or of overbank flow of major streams - In some areas includes deposits in abandoned meanders of major streams

Dune sand (Late Pleistocene) at surface, covers < 0.1 % of this area

Deposited mostly on terrace deposits of the second level. Younger than some terrace deposits, older than others

Eminence Dolomite, Potosi Dolomite (Late Cambrian-Croixian Series) at surface, covers < 0.1 % of this area

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