Usage:
/Oak formation (informal) (IL)
[Term "Formation" is applied to formal nomenclature (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021).]
Geologic age:
Quaternary
Pleistocene
Type section, locality, area and/or origin of name:
Not designated.
Reference section (subsurface): Boring ED8, Eddyville quadrangle, Pope Co., IL. Named from town of Oak, Pope Co. (Esling and others, 1991).
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 ([ ]).