Alluvial deposits on one or more terrace levels
St. Peter Sanstone and Everton Formation (Middle Ordovician)
Deposited mostly on terrace deposits of the second level. Younger than some terrace deposits, older than others
Alluvial deposits of local streams or of overbank flow of major streams - In some areas includes deposits in abandoned meanders of major streams
Powell Dolomite
Alluvial deposits in major stream channels or in mappable meanders of major streams - Includes alluvial deposits in natural levees in some areas.
Cotter and Jefferson City Dolomites
Cretaceous rocks
Alluvial deposits of present streams and on one or more terrace levels
Sand and clay
Boone Formation
Chattanooga Shale (Lower Mississippian and Upper Devonian), Clifty Limestone (Middle Devonian), and Penters Chert (Lower Devonian)
Cason Shale and Fernvale Limestone (Upper Ordovician) and Kimmswick Limestone, Plattin Limestone, and Joachim Dolomite (Middle Ordovician)