/San Carlos Tuff (TX-recognized locally in southwestern TX, notably Trans-Pecos area)
[Preoccupied. Name previously applied to Upper Cretaceous San Carlos Formation of Vaughan (1900), in Presidio Co., TX.]
Tertiary
Oligocene
Unknown.
Permian basin
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 ([ ]).