No current usage.
(†Greenbush cyclothem (informal) (IL,IN?,IA,KY) considered obsolete.)
Pennsylvanian
Type locality: in ravine tributary to Swan Creek, in E/2 sec. 24, T. 8 N., R. 1 W., Greenbush Twp., Avon quadrangle, Warren Co., IL (Wanless, 1957).
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 ([ ]).