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Sample S-7
NavDat sample number 7171 · RHYOLITE
Sample
| Sample ID | S-7 |
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| Rock name | RHYOLITE |
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| Rock type | VOLCANIC |
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| Composition | FELSIC |
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| Material | IGNEOUS |
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| Collected by | H.F. Bonham, Nevada Bureau of Mines and Geology and M.L. Silberman, U.S. Geological Survey. |
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| Comment | Rhyolite ash-flow tuff, Nine Hill Tuff. Red brown rhyolite tuff, densely welded; black vitrophyre locally present at base of unit. Tuff is locally flow-lineated. Lower part: 2-3% phenocrysts of anorthoclase, quartz and plagioclase; upper part: 15% phenocrysts of anorthoclase, minor quartz and plagioclase and a trace of biotite. Age too young. Bingler 1975 states that the Nine Hill Tuff is approximately 25 m.y. old in the Carson City area on the basis of its stratigraphic relationships with other dated ash-flow tuff units. In the Warm Springs area, stratigraphic relationships also suggest that the Nine Hill Tuff is at least 25 m.y. old. |
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Location
| Latitude | 39.7639 |
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| Longitude | -119.571 |
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| Location | Washoe Co., NV |
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| State / province | Nevada |
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Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
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| 21.7 |
|
21 |
22.4 |
|
C.L. Connor and M.L. Silberman, U.S. Geological Survey. |
Analyses
No chemical analyses are stored for this sample.
