Usage:
Bracks Rhyolite of Vieja Group (TX-local)
Recognized in southwestern TX, notably Trans-Pecos, Vieja Rim area.
Geologic age:
early Tertiary (Eocene)
Type section, locality, area and/or origin of name:
Type locality: vicinity of San Carlos, on Vieja Rim east of basin, Presidio Co., southwestern TX. Named from Bracks Canyon which cuts through rhyolite outcrop just west of San Carlos (DeFord, 1958).
AAPG geologic province:
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 ([ ]).