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National Geologic Map Database

Geologic Unit: Franciscan

Usage:

Franciscan Complex (CA*,OR)
Franciscan Formation (CA)


Subunits:

COMPLEX STATUS (alphabetical) --all in CA: Calera Limestone*, Laytonville Limestone, South Fork Mountain Schist.
FORMATION STATUS (alphabetical) --all in CA: Corral Hollow Shale Member, Del Puerto Keratophyre Member, Lotta Creek Tuff Member.


Geologic age:

Late Jurassic to Miocene*


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

Named from extensive exposures at San Francisco, San Francisco Co., western CA (Lawson, 1895; US geologic names lexicon, USGS Bull. 896).


AAPG geologic province:

California Coast Ranges province
Eel River basin
Santa Cruz 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 ([ ]).