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National Geologic Map Database

Geologic Unit: Gualala

Usage:

Gualala Formation (CA*)
Called †Wallala Beds and †Wallala Group in early reports.


Subunits:

(alphabetical) --all in CA*: Anchor Bay Member, Stewarts Point Member.


Geologic age:

Late Cretaceous*


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

Notable exposures in Point Arena-Fort Ross region in Mendocino and Sonoma Cos., northwestern CA. Named from town of Gualala at mouth of Gualala River, Mendocino Co., CA (Weaver, 1941).


AAPG geologic province:

California Coast Ranges province*


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 ([ ]).