Geologic units in Ripley county, Missouri

Smithville Dolomite, Powell Dolomite, Cotter Dolomite, Jefferson City Dolomite (Early Ordovician-Ibexian Series) at surface, covers 46 % of this area

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

Roubidoux Formation (Early Ordovician-Ibexian Series) at surface, covers 42 % of this area

Sandstone, chert and interbedded dolomite

Holocene series (Quaternary-Holocene Series) at surface, covers 7 % of this area

Alluvium - clay, silt, sand, and gravel.

Gasconade Dolomite (Early Ordovician-Ibexian Series) at surface, covers 5 % of this area

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

Cotter and Jefferson City Dolomites (Early Ordovician) at surface, covers 0.3 % of this area

Cotter and Jefferson City Dolomites

Terrace deposits (Late Pleistocene) at surface, covers 0.1 % of this area

Alluvial deposits on one or more terrace levels

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

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

Alluvium and terrace deposits (Holocene to Pleistocene) at surface, covers < 0.1 % of this area

Alluvial deposits of present streams and on one or more terrace levels

Sand and clay (Cretaceous) at surface, covers < 0.1 % of this area

Sand and clay