Usage:
Pen Formation of Terlingua Group (TX)
Geologic age:
Late Cretaceous (Coniacian to Santonian)
Type section, locality, area and/or origin of name:
Type section: about 2 mi north of Hot Springs, Brewster Co., TX (Maxwell and Hazzard, 1967).
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 ([ ]).