Usage:
Posey Canyon Shale Member of Peace Valley Formation of Ridge Basin Group (CA)
Geologic age:
Tertiary
Miocene, late
Type section, locality, area and/or origin of name:
Type section: outcrops on southwest side of Pyramid Dam and Lake, Los Angeles Co., CA. Named from Posey Canyon, which is now covered by Pyramid Lake (Link, 1982).
AAPG geologic province:
Los Angeles 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 ([ ]).