Usage:
Simpson Group (OK*,TX, and subsurface of CO*,KS*)
Subunits:
(alphabetical): Bromide Formation (OK*,TX), Corbin Ranch Formation (OK*), Fite Limestone (OK), Joins Formation (OK*,TX), McKee Sandstone (TX), McLish Formation (OK*,TX), Oil Creek Formation (OK*,TX), Platteville Formation (KS*), St. Peter Sandstone (KS*), Tulip Creek Formation (OK*,TX), Tyner Formation (OK).
Geologic age:
Middle to Late Ordovician (Whiterockian to Mohawkian)*
Type section, locality, area and/or origin of name:
Named from former village of Simpson, just north of Pontotoc, Arbuckle Mountains, Johnston Co., central southern OK (Taff, 1902).
AAPG geologic province:
Anadarko basin*
South Oklahoma folded belt*
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 ([ ]).