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Map showing publication footprint
  • Usage in publication:
    • American Ravine andesite
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Great Basin province
Publication:

Gianella, V.P., 1934, New features of the geology of the Comstock lode: Mining and Metallurgy, v. 15, no. 331, p. 298-300.


Summary:

American Ravine andesite listed in table of rocks of Comstock Lode [Lyon County, Nevada]. [Underlies] Miocene(?) Hartford Hills rhyolite. [Overlies] Jurassic monzonite. Thickness 600 feet. Age is Miocene(?) [no basis].

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


Map showing publication footprint
  • Usage in publication:
    • American Ravine andesite
  • Modifications:
    • Named
  • Dominant lithology:
    • Andesite
    • Porphyry
  • AAPG geologic province:
    • Great Basin province
Publication:

Gianella, V.P., 1936, Geology of Silver City district and southern portion of Comstock Lode, Nevada: Nevada Bureau of Mines and Geology and Mackay School of Mines Bulletin, no. 29, 105 p., (incl. geologic map, scale 1:33,867), Also issued as Univ. Nevada Bull., v. 30, no. 9, 1936.


Summary:

Pg. 33, 44-50, 50-52, pl. 1; see also V.P. Gianella, 1936, Mining and Metallurgy, v. 15, no. 331, p. 209 (table 1). American Ravine andesite. Light-gray felsitic hornblende andesite about 500 feet thick. Underlies Hartford Hill rhyolite; overlies fanglomerate, monzonite, or metamorphic rocks. Becker (1882) mapped this rock as felsitic quartz porphyry. Age is Eocene, based on stratigraphic relations.
Notable exposures on east side of Virginia Range, near Virginia City, NV. [Probably named from American Ravine west of Silver City, Silver City district, south end of Virginia Range, 12 mi northeast of Carson City, Lyon Co., NV.]

Source: US geologic names lexicon (USGS Bull. 1200, p. 76-77); GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • American Ravine andesite porphyry*
  • Modifications:
    • Adopted
    • Age modified
  • AAPG geologic province:
    • Great Basin province
Publication:

Calkins, F.C., 1944, Outline of the geology of the Comstock Lode district, Nevada: U.S. Geological Survey Open-File Report, OFR-45-29, 35 p., (incl. map by Calkins and Thayer, 1945, scale 1:24,000)


Summary:

American Ravine andesite (Gianella, 1936) adopted as the American Ravine andesite porphyry. Intrusive into rhyolite [mainly Eocene] and probably into lower part of Alta andesite [Miocene]. Age therefore changed from Eocene to Miocene(?).

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


Map showing publication footprint
  • Usage in publication:
    • American Ravine Andesite Porphyry*
  • Modifications:
    • Age modified
  • AAPG geologic province:
    • Great Basin province
Publication:

Stewart, J.H., 1999, Geologic map of the Carson City 30' x 60' quadrangle, Nevada and California: Nevada Bureau of Mines and Geology Map, no. 118, scale 1:100,000 [Available online from the Nevada Geological Survey and the NGMDB map catalog: http://ngmdb.usgs.gov/Prodesc/proddesc_26507.htm]


Summary:

Age of the American Ravine Andesite Porphyry is revised from Miocene(?) to: Miocene [based on local stratigraphic relations in the Comstock Lode district in western Virginia Range].

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


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

Asterisk (*) indicates published by U.S. Geological Survey authors.

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