Usage:
No current usage.
(†Bidwell Coal Member of †Spoon Formation (IL-local) is synonym of Delwood Coal Bed of Tradewater Formation of Raccoon Creek Group. See Delwood.)
Geologic age:
Middle Pennsylvanian (Desmoinesian)
Type section, locality, area and/or origin of name:
Type locality: in NE/4 SE/4 SW/4 sec. 5, T. 11 S., R. 4 E., Marion 15-min quadrangle, Johnson Co., southeastern IL. Named from Bidwell School, about 0.75 mi southwest of type locality (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 ([ ]).