No current usage.
(†Flannigan cyclothem (informal) in McLeansboro Group (IL) considered obsolete.)
Pennsylvanian
Named from Flannigan Twp., in T. 6 S., R. 5 E., Hamilton Co., IL (Newton and Weller, 1937; Weller, 1942).
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 ([ ]).