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Sample 56-B-1
NavDat sample number 8387 · RHYOLITE
Sample
| Sample ID | 56-B-1 |
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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 | Gray to buff colored lava, often pumiceous; plagioclase An30-50, orthopyroxene, clinopyroxene, hornblende, and titanomagnetite phenocrysts set in a pilotaxitic cryptocrystalline groundmass dominated by plagioclase microlites and opaques. |
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Location
| Latitude | 41.6359 |
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| Longitude | -121.718 |
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| State / province | California |
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| Volcanic field | Medicine Lake Highland |
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| Location comment | 1/2 mi SW of hill 5598, on west side of barranca that separates this dome from the one represented by sample 47-B-1 |
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Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
|---|
| 0.95 |
|
0.81 |
1.09 |
|
|
Analyses
Whole rock
| Item | Value | Std. dev. | Unit | Method |
|---|
| SIO2 | 71.47 | | WT% | XRF |
| AL2O3 | 14.48 | | WT% | XRF |
| FEO | 0.91 | | WT% | XRF |
| FE2O3 | 1.63 | | WT% | XRF |
| TIO2 | 0.31 | | WT% | XRF |
| MNO | 0.06 | | WT% | XRF |
| MGO | 0.51 | | WT% | XRF |
| CAO | 1.66 | | WT% | XRF |
| NA2O | 4.78 | | WT% | XRF |
| K2O | 3.18 | | WT% | XRF |
| P2O5 | 0.09 | | WT% | XRF |
