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National Geologic Map Database

Geologic Unit: Los Trancos

Usage:

Los Trancos Member of Topanga Formation (CA*-recognized locally in San Joaquin Hills, Orange Co.)


Geologic age:

Tertiary
Miocene, middle*


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

Typical exposures occur between Los Trancos Canyon and Bonita Creek in western part of San Joaquin Hills [Laguna Beach and Tustin 7.5-min quadrangles, Orange Co., CA] (Vedder and others, 1957).


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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).