Usage:
Alhambra Formation (CA)
Subunits:
(alphabetical) --all in CA: Castro Shale Member, Pereira Shale Member, Roop Sandstone Member.
Geologic age:
early Tertiary (Eocene)
Type section, locality, area and/or origin of name:
Type section: west limb of Pacheco syncline in Santa Fe cuts east of east portal of Muir Tunnel near Martinez, Contra Costa Co., west-central CA (Weaver, 1953).
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 ([ ]).