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Sample 8
NavDat sample number 4458 · PHONOLITE
Sample
| Sample ID | 8 |
|---|
| Rock name | PHONOLITE |
|---|
| Rock type | PLUTONIC |
|---|
| Composition | INTERMEDIATE |
|---|
| Material | IGNEOUS |
|---|
| Comment | porphyritic with phenocrysts of orthoclase exsolved to albite, aegerine-augite; groundmass is trachytic and composed of aegerine augite and analcime or sodalite |
|---|
Location
| Latitude | 44.3312 |
|---|
| Longitude | -103.806 |
|---|
| Location | Green Mountain west |
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| State / province | South Dakota |
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| Volcanic field | Green Mountain west phonolite |
|---|
Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
|---|
| 50 |
|
45 |
55 |
|
|
Analyses
Whole rock
| Item | Value | Std. dev. | Unit | Method |
|---|
| SIO2 | 44 | | WT% | GRAV |
| NA2O | 8 | | WT% | AAS |
| MGO | 0.046 | | WT% | AAS |
| K2O | 4 | | WT% | AAS |
| CAO | 0.28 | | WT% | AAS |
| SR87_SR86 | 0.7055 | | | MS |
