U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database

Geologic Unit: Simpson

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 usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).