Tertiary and Cretaceous undivided

Tertiary and Cretaceous undivided.
State Illinois
Name Tertiary and Cretaceous undivided
Geologic age Upper Cretaceous (Campanian) to Tertiary (Pliocene)
Lithologic constituents
Sedimentary > Clastic > Mixed-clastic > Siltstone-mudstone (Bed, Glauconitic, Carbonaceous)Silty shale is portrayed on stratigraphic column. Owl Creek and Clayton Fms contain glauconite. McNairy Fm is carbonaceous.
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Coal (Bed)
Comments Thickness from stratigraphic column for southern Illinois (south of 40 degrees north latitude), from oldest to youngest: Post Creek Fm (0-75'), Baylis Fm (0-100'), McNairy Fm (0-450'), Owl Creek Fm (0-10'), Clayton Fm (0-20'), Porters Creek Fm (0-150'), Claiborne and Wilcox Formations (0-300'), Mounds Gravel (0-70'), Grover Gravel (0-50'). The Baylis Fm (western Illinois) is laterally equivalent to the Post Creek Fm (southern Illinois); the Mounds Gravel is laterally equivalent to the Grover Gravel. [TKu is mapped only in southern Illinois.]
Stratigraphic units Baylis Formation, Post Creek (Tuscaloosa) Formation, McNairy Formation, Owl Creek Formation, Clayton Formation, Porters Creek Formation, Claiborne Formation, Wilcox Formation, Mounds Gravel, Grover Gravel

Kolata, D.R., comp., 2005, Bedrock Geology of Illinois: Champaign, Ill., Illinois State Geological Survey, Illinois Map Series 14, scale 1:500,000.

NGMDB product
Counties Alexander - Union