Cypress Sandstone (IL*,KY*,TN*)
Cypress Formation (KY*,MO)
Cypress Sandstone of West Baden Group (IL,IN)
Cypress Formation of West Baden Group (IN)
Middle Mississippian (Visean; early Chesterian)*
Not designated. Named from Cypress Creek, southeast Union Co., IL (Engelmann 1868).
Typical exposures generally accepted as type section, IL (Swann 1963).
Reference section in MO (Thompson, 1986).
Cincinnati arch*
Illinois basin*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).