Usage:
Gill Breccia of Vieja Group (TX-local)
Recognized in southwestern TX, notably Rim Rock country.
Geologic age:
Tertiary
Eocene
Type section, locality, area and/or origin of name:
Colmena Canyon (Gill Canyon) in the Rim Rock country, Presidio Co., southwestern TX (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 ([ ]).