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Geologic Unit: Topanga
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Map showing publication footprint
  • Usage in publication:
    • Topanga formation*
  • Modifications:
    • First used
    • Biostratigraphic dating
  • Dominant lithology:
    • Sandstone
  • AAPG geologic province:
    • Transverse Ranges province
Publication:

Kew, W.S.W., 1923, Geologic formations of a part of southern California and their correlation: American Association of Petroleum Geologists Bulletin, v. 7, no. 4, p. 411-420. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Named proposed to include rocks in Santa Monica and Santa Ana Mountains lying below Modelo formation and above Vaqueros formation and containing TURRITELLA OCOYANA fauna. Formerly included in Vaqueros formation (now restricted to TURRITELLA INEZANA fauna). Strata are essentially sandstone. Overlies true Vaqueros formation; in Topanga Canyon, Los Angeles Co, unconformably underlies Modelo formation. Age is middle Miocene based on fauna.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Topanga formation*
  • Modifications:
    • Named
    • Biostratigraphic dating
  • Dominant lithology:
    • Sandstone
  • AAPG geologic province:
    • Transverse Ranges province
Publication:

Kew, W.S.W., 1924, Geology and oil resources of a part of Los Angeles and Ventura Counties, California: U.S. Geological Survey Bulletin, 753, 202 p., (incl. geologic map, scale 1:62,500)


Summary:

Named for Topanga Canyon, Los Angeles Co, CA. Formerly included in part in Vaqueros formation and in part in Modelo formation by Kew (1919). Best developed on Santa Monica Mountain; also crops out south and west of Simi Hills and along Santa Susana fault north of Fernando Valley. Consists mainly of well-bedded tan and brown sandstone containing large round concretions and minor conglomerate. Fossils are common. Is about 6000 ft thick on nose of Topanga anticline. Overlies Meganos formation in Simi region and Vaqueros formation. Underlies Modelo formation. Mollusks (listed) and stratigraphic position indicate middle Miocene age.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Topanga formation*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Transverse Ranges province
Publication:

Shelton, J.S., 1946, Geology of northeast margin of San Gabriel basin, Los Angeles County, California: U.S. Geological Survey Oil and Gas Investigations Map, OM-63, scale 1:24,000


Summary:

Topanga formation of Santa Monica Mountains is recognized in San Gabriel basin on basis of faunal and lithologic similarities. Best exposed in South Hills where unit is about 2000 ft thick and in vicinity of Azusa Rainbow Club where unit is about 2500 ft thick. Overlies Glendora volcanics (new). Unconformably underlies Quaternary alluvium. Age is middle Miocene.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Topanga formation*
  • Modifications:
    • Areal extent
    • Revised
  • AAPG geologic province:
    • Transverse Ranges province
Publication:

Woodford, A.O., Moran, T.G., and Shelton, J.S., 1946, Miocene conglomerates of Puente and San Jose Hills, California: American Association of Petroleum Geologists Bulletin, v. 30, no. 4, p. 514-560. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Topanga formation is recognized in San Jose Hills, 5 mi west of Pomona, where thick conglomerate in core of Buzzard Peak anticline is designated Buzzard Peak conglomerate member (new) of Topanga formation. Member is about 2000 ft thick; base not exposed but overlies volcanic rocks in Continental Oil Bayly well no.1 at depth of 2300 ft. Conformably underlies lower member of Puente formation or intervening andesite breccia. Age is middle Miocene based on stratigraphic position.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Topanga formation*
  • Modifications:
    • Areal extent
    • Revised
  • AAPG geologic province:
    • Transverse Ranges province
Publication:

Vedder, J.G., Yerkes, R.F., and Schoellhamer, J.E., 1957, Geologic map of the San Joaquin Hills-San Juan Capistrano area, Orange County, California: U.S. Geological Survey Oil and Gas Investigations Map, OM-193, scale 1:24,000


Summary:

Topanga formation recognized in San Joaquin Hills-San Juan Capistrano area. Northwest of Laguna Canyon unit divided into three members (oldest to youngest): Bommer, Los Trancos and Paularino members (all new). Age is middle Miocene.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Topanga Group*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Transverse Ranges province
Publication:

Yerkes, R.F., and Campbell, R.H., 1979, Stratigraphic nomenclature of the central Santa Monica Mountains, Los Angeles County, California, IN Contributions to stratigraphy, 1979: U.S. Geological Survey Bulletin, 1457-E, p. E1-E30.


Summary:

In central and western Santa Monica Mountains west of Topanga Canyon, Topanga Formation as defined by Kew (1923) is raised in rank to Topanga Group. Subdivided into (ascending): Topanga Canyon Formation (new), Conejo Volcanics and Calabasas Formation (new). Age is middle Miocene.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


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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 ( ).

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