No current usage.
(Grand Gulf Group (LA,MS) abandoned. Rocks reallocated to Catahoula and Fleming Formations. See Catahoula and Fleming.)
Oligocene and Miocene
Named from exposures in bluff at Grand Gulf, Claiborne Co., MS (US geologic names lexicons, USGS Bull. 896, 1200).
Gulf Coast basin
Mid-Gulf Coast basin
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 ([ ]).