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National Geologic Map Database
Geologic Unit: Neenach
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Map showing publication footprint
  • Usage in publication:
    • Neenach Volcanic Formation*
  • Modifications:
    • Named
  • Dominant lithology:
    • Andesite
    • Volcanics
  • AAPG geologic province:
    • Mojave basin
Publication:

Dibblee, T.W., Jr., 1967, Areal geology of the western Mojave Desert, California: U.S. Geological Survey Professional Paper, 522, 153 p., (incl. geologic map, scale 1:125,000)


Summary:

Named Neenach Volcanic Formation. Extends from hills west of Antelope Valley, northeast of San Andreas fault, in narrow strip adjacent to fault near Gorman, and from La Liebre Ranch southeast to Pine Canyon. Consists of dark reddish- to purplish-brown andesite and light-colored, greenish-gray, pink, red-brown to tan felsite with minor perlite, tuff breccia and bentonite. Unconformably overlies pre-Tertiary granitoid rocks. Unconformably underlies Oso Canyon Formation (new) of late Miocene age. Age is considered possibly Oligocene(?) and early or middle Miocene, based on regional correlation.
Named from former school in Neenach 15-min quadrangle. Type section: exposures in large canyon, a mi east of La Liebre Ranch (projected S/2 sec. 14, sec. 23, T. 8 N., R. 17 W.) [La Liebre Ranch 7.5'-min quadrangle, Los Angeles Co., CA].

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


Map showing publication footprint
  • Usage in publication:
    • Neenach Volcanics*
  • Modifications:
    • Redescribed
    • Age modified
  • AAPG geologic province:
    • Mojave basin
Publication:

Sims, J.D., 1993, Chronology of displacement on the San Andreas Fault in central California; evidence from reversed positions of exotic rock bodies near Parkfield, California, IN Powell, R.E., Weldon, R.J., II, and Matti, J.C., eds., The San Andreas fault system; displacement, palinspastic reconstruction, and geologic evolution: Geological Society of America Memoir, 178, p. 231-256.


Summary:

Neenach Volcanic Formation of Dibblee (1967) redefined as Neenach Volcanics to conform with North American Stratigraphic Code (1983). Age is early Miocene based on correlation with Pinnacles Volcanics.

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


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"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 ([ ]).