Sample: 81ARj 11b
| Sample ID: | 81ARj 11b [1] |
| Station ID: | 81ARj 11b |
| AT Num: | |
| Volcano: | Ugashik caldera |
| Possible source: | |
| Eruption: | |
| Collector: | Riehle, J. R. |
| Date sampled: | 1981-01-01 |
| Sample type 1: | Other |
| Color: | |
| Final unit: | |
| Text Description: | Vitric clast from volcanic breccia. Porphyritic plagioclase-pyroxene-hornblende dacite (S; high-silica andesite G). Glassy groundmass contains abundant randomly oriented phenocrysts of plagioclase (An 70), clinopyroxene, hornblende, and biotite. Clinopyroxene are pleochroic from tan to pale green, hornblende is pleochroic from brown to yellow brown. Hornblende and biotite crystals outlined in opaque minerals, clinopyroxene altered on edges to brown aphanitic phase. Plagioclase is variably zoned. |
| Sample Location: |