No current usage.
(†Briar Hill cyclothem (informal) (IL) considered obsolete.)
Middle Pennsylvanian (Desmoinesian)
Named from Briar Hill near village of DeKoven, Union Co., western KY (Kosanke and others, 1960).
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 ([ ]).