Usage:
No current usage.
(†Alamo Formation (CA) replaced with Diablo Formation. See Diablo.)
Geologic age:
late Tertiary (early Pliocene)
Type section, locality, area and/or origin of name:
Notable exposures in vicinity of Mount Diablo Country Club on southwest side of Mount Diablo, [Diablo 7.5-min quadrangle], Contra Costa Co., northern CA (Condit, 1938).
AAPG geologic province:
Sacramento 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 ([ ]).