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Sample WC91-23
NavDat sample number 48654 · MONZONITE
Sample
| Sample ID | WC91-23 |
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| Rock name | MONZONITE |
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| Rock type | PLUTONIC |
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| Composition | FELSIC |
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| Material | IGNEOUS |
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| Comment | prominent euhedral cpx similar to those in Square Butte intrusion; no obvious K-bearing phases in main mass of shonkinite but diversely oriented leucocratic veins, possibly representing late-stage melt segregation, contain euhedral platy minerals appearing to be biotite |
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Location
| Latitude | 47.4742 |
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| Longitude | -111.835 |
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| Location | taken from freshly blasted leucocratic vein exposed in quarry, north side of Shaw Butte |
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| State / province | Montana |
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| Volcanic field | Shaw Butte laccolith |
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Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
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| 73.68 |
|
73.28 |
74.08 |
|
|
Analyses
No chemical analyses are stored for this sample.
References
- Harlan, Stephen S; Snee, Lawrence W; Reynolds, Mitchell W; Mehnert,Harald H; Schmidt, R G; Sheriff, Steve D; Irving, Anthony J (2005) U. S. Geological Survey Professional Paper, Report: P 1696, 29 pp.,2005
