Usage:
Oregonia Member of Arnheim Formation of Cincinnati group (informal) (OH)
(informal Cincinnati group is the usage of the OH Geol. Survey. The rank or lithologic term should not be capitalized.)
Geologic age:
Late Ordovician (Cincinnatian; Maysvillian to Richmondian)
Type section, locality, area and/or origin of name:
Oregonia, Warren Co., southwestern OH (Foerste, 1910).
AAPG geologic province:
Cincinnati arch
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 ([ ]).