- Usage in publication:
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- Calloway Well Formation
- Modifications:
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- Named
- Dominant lithology:
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- Ignimbrite
- AAPG geologic province:
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- Great Basin province
Summary:
Tertiary rocks in Grant Range consists of 5,000 to 15,000 ft of rhyolitic ignimbrite sheets, nonmarine sediments and siliceous flows. Major named units are (ascending); Sheep Pass Formation, middle to upper Eocene; Railroad Valley Rhyolite (new), 36 Ma; Calloway Well Formation (new), ignimbrites; Stone Cabin Formation, ignimbrites; Windous Butte Formation, ignimbrites, 33 Ma; Currant Tuff; Needles Range Formation, ignimbrites; Horse Camp Formation, Miocene to Pliocene.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
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- Calloway Well Formation
- Modifications:
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- Overview
- AAPG geologic province:
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- Great Basin province
Summary:
Pg. 275 (fig. 2). Calloway Well Formation. Listed in generalized stratigraphic chart of Cenozoic section of Grant Range, Nye County, Nevada. Ignimbrite, 0 to 600 feet thick. Overlies Blind Spring Formation and underlies Saddle Mountain Andesite (both new). Age is Oligocene.
Oligocene units are (ascending): Railroad Valley Rhyolite, Blind Spring Formation (new), Calloway Well Formation, Saddle Mountain Andesite (new), Stone Cabin Formation, local andesite flows, Currant Tuff, Windous Butte Formation, Forest Home Ignimbrite (new), Needles Range Formation, and Shingle Pass Formation.
Source: US geologic names lexicon (USGS Bull. 1350, p. 112); GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
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- Calloway Well Formation
- Modifications:
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- Areal extent
- AAPG geologic province:
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- Great Basin province
Summary:
Calloway Well Formation (0 to 600 ft thick) is oldest ignimbrite in White Pine-Grant Range area. Is multiple-flow rhyolitic unit. In southern part of area, one compound, highly welded unit is present; at Stone Cabin, nine slightly welded individual units are found. Shown on geologic map of White Pine-Grant Range region. Cross-section shows formation extends to Horse Camp Basin.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
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- Calloway Well Formation
- Modifications:
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- Geochronologic dating
- AAPG geologic province:
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- Great Basin province
Summary:
K-Ar determinations on biotite from two samples of Calloway Well Formation yielded 34.1 +/-0.7 Ma (collected at 38 deg 33' 25"N, 115 deg 22' 40"W) and 32.3 +/-0.7 Ma (collected at 38 deg 39' 55"N, 115 deg 21' 45"W). Preferred estimate of age of unit is 34.1 +/-0.7 Ma because sample is better welded and less altered.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
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- Calloway Well Formation
- Modifications:
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- Not used
- AAPG geologic province:
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- Great Basin province
Summary:
Lower sheet of Stone Cabin Formation of Cook (1965) "has been renamed the Calloway Well Formation by Scott (1966) and Armstrong (1970), a usage which is not here adopted." p.1624.
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 ([ ]).