Usage:
Black Peaks Formation (TX)
Black Peaks Formation of Tornillo Group (TX)
Black Peaks Member of Tornillo Formation of Chilicotal Group (TX)
Geologic age:
Tertiary
Paleocene
Torrejonian
Type section, locality, area and/or origin of name:
Named from three small black peaks on east side of Tornillo Flat, northwest of McKinney Hills, Big Bend National Park, Brewster Co., southwestern TX. Type section in north-central part of Tornillo Flat (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 ([ ]).