- Usage in publication:
-
- Sweetwater Formation
- Modifications:
-
- Named
- Dominant lithology:
-
- Sandstone
- Claystone
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Occurs east of San Diego Bay along east side of La Nacion fault, San Diego Co, southwestern CA. Distribution shown on geologic sketch map of San Diego area. Consists of lower gritty sandstone member and upper 35-m-thick red claystone member. Overlies Poway Conglomerate and metamorphic and granitic rocks of Jurassic to Cretaceous age; underlies Otay Formation (new). [Otay Formation later abandoned in favor of Rosarito Beach Formation (Scheidemann and Kuper, 1979)]. Only unidentifiable mammal fossils have been recovered from Sweetwater Formation. Age is Eocene on basis of stratigraphic relations.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Sweetwater Member
- Modifications:
-
- Revised
- Age modified
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Sweetwater Formation of Artim and Pinckney (1973) reduced in rank to member and assigned to Rosarito Beach Formation. Best complete section is found between Acacia Ave. and Otay Lake Road in Bonita along south side of Sweetwater Valley, National City 7.5' quad, San Diego Co, CA. Overlies Mission Valley Formation; underlies Otay Member of Rosarito Beach Formation. Age is Miocene based on gradational contact between Sweetwater and Otay Members and lithological character of Miocene conglomerates in San Diego area.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Sweetwater Formation
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Peninsular Ranges province
Summary:
Sweetwater Formation of Artim and Pinckney (1973) is retained. Type section, designated as 0.5 mi west of junction of Sweetwater Valley Road and South Bay Freeway (32 deg 42'03"N, 117 deg 58'39"W), is 42 m thick. Disconformably overlies Mission Valley Formation or Mesozoic rocks. Underlies Rosarito Beach and San Diego Formations. Age given as Miocene.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
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 ([ ]).