Usage:
No current usage.
(†O'Nan Coal Member of †Spoon Formation [now Tradewater Formation] (IL,KY) considered abandoned. Is same as informal Dawson Springs (No. 4), Lewisport, Mannington, and Mining City coals of KY [not included in this lexicon].)
Geologic age:
Middle Pennsylvanian (Desmoinesian)
Type section, locality, area and/or origin of name:
At Indian Hill, near Curlew, Union Co., west-central KY. Named from Dennis O'Nan Ditch, which flows across north tip of Indian Hill, DeKoven quadrangle (Kosanke and others, 1960).
AAPG geologic province:
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 ([ ]).