No current usage.
(†Archimedes limestone (informal) (AR,IL,MO,OK) abandoned and replaced with Palestine Sandstone (IL), Ste. Genevieve Limestone (MO,IL), Warsaw Limestone (MO,IL), Keokuk Limestone (MO,IL) and Pitkin Limestone (AR,OK). See Palestine, Ste. Genevieve, Warsaw, Keokuk, and Pitkin.)
Mississippian
Named from the fossil ARCHIMEDES (Simonds, 1891).
Illinois basin
Ozark uplift
Chautauqua platform
Arkoma 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 ([ ]).