Las Posas Formation (CA)
Long Canyon Member (CA).
Quaternary (Pleistocene)
Origin of name not stated by author, but probably named from Las Posas Hills, Ventura Co., south-central CA (Pressler, 1929).
Los Angeles basin
Ventura 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 ([ ]).