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National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Jackhammer Formation*
  • Modifications:
    • Named
  • Dominant lithology:
    • Sandstone
    • Siltstone
    • Tuff
    • Limestone
  • 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Named by McCulloh (1952, unpublished thesis) and here adopted. Is discontinuous thin basal sedimentary and volcanic formation exposed only in Mud Hills; best exposed in Owl Canyon; 150 ft maximum thickness. Lower 30-100 ft arkosic sandstone and siltstone; upper part 5-20 ft bedded white tuff overlain by 5-30 ft vesicular basalt. Half mile east of Owl Canyon, formation composed of lenses up to 50 ft thick of gray limestone; further east composed of granitic boulder conglomerate. Unconformable on quartz monzonite. Overlain by Pickhandle Formation. Age presumably Oligocene or early Miocene.

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


Map showing publication footprint
  • Usage in publication:
    • Jackhammer Formation*
  • Modifications:
    • Age modified
    • Geochronologic dating
  • AAPG geologic province:
    • Mojave basin
Publication:

Burke, D.B., Hillhouse, J.W., McKee, E.H., Miller, S.T., and Morton, J.L., 1982, Cenozoic rocks in the Barstow basin area of southern California; stratigraphic relations, radiometric ages, and paleomagnetism, IN Contributions to stratigraphy: U.S. Geological Survey Bulletin, 1529-E, p. E1-E16, (incl. geologic map, scale 1:125,000)


Summary:

Age of Jackhammer Formation is revised from Oligocene or early Miocene to early Miocene based on stratigraphic position between radiometrically-dated volcanic units (18.9 +-1.3 Ma date on overlying Opal Mountain Volcanic Member of Pickhandle Formation and 23.1+-0.2 Ma for underlying Lane Mountain Quartz Latite).

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 ([ ]).

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