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National Geologic Map Database

Geologic Unit: Topanga

Usage:

Topanga Group (CA*)
Topanga Formation (CA*)


Subunits:

GROUP STATUS (alphabetical) --all in CA*: Calabasas Formation, Conejo Volcanics, Topanga Canyon Formation.
FORMATION STATUS (alphabetical) --all in CA*: Bommer Member, Buzzard Peak Conglomerate Member, Los Trancos Member, Paularino Member.


Geologic age:

Tertiary
Miocene, middle*


Type section, locality, area and/or origin of name:

Topanga Canyon, 10 mi northwest of Santa Monica, Los Angeles Co., CA (Kew, 1924; Susuki, Takeo [abs.], GSA Bull., v. 63, no. 12, pt. 2).


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 ([ ]).