Sample: BCM-13
| Sample ID: | BCM-13 [1] |
| Station ID: | BCM-13 |
| AT Num: | |
| Volcano: | Tanada Peak |
| Possible source: | |
| Eruption: | |
| Collector: | Unknown, Unknown |
| Date sampled: | |
| Sample type 1: | Lava |
| Color: | |
| Final unit: | |
| Text Description: | Wrangell Lava. Tanada volcano. Intracaldera flows. Medium to thick (5-30 m), dark-gray to greenish-gray, porphyritic andesite flows. Chiefly augite-olivine andesites containing phenocrysts of plagioclase (5-20%, 1-10 mm), augite (trace to 3%, 1-2 mm), and olivine (trace to 2%, 3-5 mm) in a pilotaxitic to intergranular groundmass. Mafic minerals generally altered to clay minerals and serpentine; vesicles mostly filled with celadonite and calcite. Pyroclastic deposits, shown by dashed line labeled t, are chiefly bedded andesite lapilli airfall tuffs. An area of brecciation, hydrothermal alteration, and small dikes, shown by small triangles, occurs in the south-central part of the caldera and may mark the locus of long-lived post-caldera eruptive and thermal activity. |
| Sample Location: |