Usage:
No current usage.
(†Amador Group (CA) abandoned.)
Geologic age:
Middle to Late Jurassic
Type section, locality, area and/or origin of name:
Type sections: (1) "northern end" on banks of Cosumnes River downstream from upper contact of Logtown Ridge Formation at Huse Bridge on Highway 49, southwestern El Dorado and northwestern Amador Cos., east-central CA; (2) "southern end" on Merced River (Taliaferro, 1943; see also Clark, 1964).
Type section [restricted]: on Consumnes River, extending west from Huse Bridge on Highway 49 to about 2.1 mi southwest of Huse Bridge, in vicinity of Lat. 38 deg. 32 min. 30 sec. N., Long. 120 deg. 52 min. 30 sec. W. (Clark, 1964, pl. 10; =northern type section of Taliaferro).
AAPG geologic province:
Sierra Nevada province
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 ([ ]).