Usage:
No current usage.
(†Oklan Series or †Oklan Epoch considered obsolete.)
Geologic age:
Pennsylvanian, Middle
Type section, locality, area and/or origin of name:
Name Oklan is based on abbreviation of State of Oklahoma and refers to the thick fossiliferous succession of Middle Pennsylvanian deposits in east-central and northwestern Oklahoma (Moore and Thompson, 1949).
AAPG geologic province:
North America
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 ([ ]).