← Search
Sample JM-80
NavDat sample number 9437 · TRACHYTE
Sample
| Sample ID | JM-80 |
|---|
| Rock name | TRACHYTE |
|---|
| Rock type | VOLCANIC |
|---|
| Composition | INTERMEDIATE |
|---|
| Material | IGNEOUS |
|---|
| Comment | occurs as dikes, sills, and small intrusive masses; excellent trachytic texture defined by sanidine, the dominant mineral, in phenocrysts; also contains aegerine-augite, melanite, and analcite; groundmass comprises at least 70% of rock and consists mainly of sanidine and aegerine |
|---|
Location
| Latitude | 47.2444 |
|---|
| Longitude | -109.033 |
|---|
| State / province | Montana |
|---|
| Volcanic field | Linster Peak Dome |
|---|
Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
|---|
| 67 |
|
64 |
69 |
|
|
Analyses
Whole rock
| Item | Value | Std. dev. | Unit | Method |
|---|
| SIO2 | 57.33 | | WT% | XRF |
| AL2O3 | 20 | | WT% | XRF |
| TIO2 | 0.38 | | WT% | XRF |
| FEOT | 5.68 | | WT% | XRF |
| MNO | 0.15 | | WT% | XRF |
| CAO | 1.74 | | WT% | XRF |
| MGO | 0.82 | | WT% | XRF |
| K2O | 8.99 | | WT% | XRF |
| NA2O | 4.84 | | WT% | XRF |
| P2O5 | 0.06 | | WT% | XRF |
| TOTAL | 99.99 | | WT% | XRF |
| RB | 154 | | PPM | XRF |
| SR | 632 | | PPM | XRF |
