- Usage in publication:
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- Carlotta formation
- Modifications:
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- Original reference
- Dominant lithology:
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- Conglomerate
- Sandstone
- Claystone
- AAPG geologic province:
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- Eel River basin
Summary:
Pg. 13 (fig. 3), 35-39, 44-47, 113-115, pls. Carlotta formation of Wildcat group. Predominantly massive nonmarine conglomerate, sandstone, and carbonaceous claystone; some marine lenses; locally contains white volcanic ash beds. Thickness 500 to 3,000 feet. Uppermost formation of group; unconformably underlies Hookton formation (new); overlies Scotia Bluffs sandstone (new) of Wildcat group with contact gradational. Fossils [listed], notably leaves, vertebrates. Age is Pliocene to Pleistocene.
Type section: near town of Carlotta, Humboldt Co., northwestern CA. No complete well exposed section exists. Principal distribution is in trough of major Eel River syncline and in western part of Fortuna quadrangle. Westward plunge of Cenozoic structures and the Little Salmon Creek fault limit eastward extent.
Source: Publication; US geologic names lexicon (USGS Bull. 1200, p. 639-640).
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 ([ ]).