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Sample 82-18
NavDat sample number 10023 · RHYOLITE
Sample
| Sample ID | 82-18 |
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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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| Comment | Cream- to buff- to pink-colored lava, often pumiceous, with patches of spherulites well developed; infrequent small <1mm phenocrysts of plagioclase An30-40 set in a cryptocrystalline felsitic aggregate containing randomly oriented feldspar microlites. |
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Location
| Latitude | 41.6102 |
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| Longitude | -121.465 |
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| State / province | California |
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| Volcanic field | Medicine Lake Highland |
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| Location comment | from pumice pit immediately E of Recent Glass Mountain obsidian flow |
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Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
|---|
| 0.48 |
|
0.42 |
0.54 |
|
|
Analyses
Whole rock
| Item | Value | Std. dev. | Unit | Method |
|---|
| SIO2 | 75.94 | | WT% | XRF |
| AL2O3 | 13.01 | | WT% | XRF |
| FEO | 0.18 | | WT% | XRF |
| FE2O3 | 1.12 | | WT% | XRF |
| TIO2 | 0.08 | | WT% | XRF |
| MNO | 0.04 | | WT% | XRF |
| MGO | 0 | | WT% | XRF |
| CAO | 0.47 | | WT% | XRF |
| NA2O | 3.94 | | WT% | XRF |
| K2O | 4.84 | | WT% | XRF |
| P2O5 | 0.01 | | WT% | XRF |
