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Geologic Units: Ashdown
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Map showing publication footprint
  • Usage in publication:
    • Ashdown Tuff*
  • Modifications:
    • Named
  • Dominant lithology:
    • Tuff
  • AAPG geologic province:
    • Great Basin province
Publication:

Noble, D.C., McKee, E.H., Smith, J.G., and Korringa, M.K., 1970, Stratigraphy and geochronology of Miocene volcanic rocks in northwestern Nevada, IN Geological Survey Research 1970: U.S. Geological Survey Professional Paper, 700-D, p. D23-D31.


Summary:

Named for Ashdown Mine on west side of Pine Forest Range. Type locality designated as exposures of the thickest cooling unit in canyon walls of Cove Creek, NE/4 sec.2 T42N R27E, Idaho Canyon quad, central Black Rock Range, Humboldt Co, northwest NV. Composed of a cliff forming, tan to brown densely welded, devitrified porphyritic tuff. Is 60 m thick. Overlies unnamed volcanic units. Underlies Steens Basalt. Assigned early Miocene age based on K-Ar ages of 25.3 +/-0.9 and 23.7 +/-0.7 Ma on a sanidine separate, collected from 41 deg 35' 40"N, 118 deg 51' 10"W, NV.

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


Map showing publication footprint
  • Usage in publication:
    • Ashdown Tuff*
  • Modifications:
    • Age modified
    • Areal extent
  • AAPG geologic province:
    • Great Basin province
Publication:

Roback, R.C., Van der Meulin, D.B., King, H.D., and Plouff, Donald, 1987, Mineral resources of the Pueblo Mountains Wilderness Study Area, Harney County, Oregon, and Humbolt County, Nevada, IN Mineral resources of wilderness study areas; Steens Mountain-Rincon region, Oregon: U.S. Geological Survey Bulletin, 1740-B, p. B1-B30, (incl. geologic map, scale 1:48,000)


Summary:

Geographically extended to Pueblo Mountains Wilderness Study Area, Harney Co, OR, and Humboldt Co, NV. [Underlies Steens Basalt]. Age shown on map as Miocene and Oligocene. [no basis given for age change]

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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