Sample: 96-ARh-38C
| Sample ID: | 96-ARh-38C [1] [2] |
| Station ID: | 96-ARh-38 |
| AT Num: | |
| Volcano: | Akutan |
| Possible source: | |
| Eruption: | |
| Collector: | Richter, D. H. |
| Date sampled: | 1996-00-00 |
| Sample type 1: | Other |
| Color: | gray |
| Final unit: | aau |
| Text Description: | Qaa - volcanic rocks of ancestral Akutan volcano (Pleistocene). Lava flows and minor volcaniclastic rocks, undifferentiated. Chiefly medium (3-4 m thick) to thick (>5 m) flows interlayered with minor lahars and airfall lapilli tuffs, especially at higher elevations. Flows are medium to dark gray and range from fine-grained aphanitic to highly porphyritic. Porphyritic varieties are basalts and basaltic andesites containing phenocrysts of plagioclase (10-40%, 1-5 mm), olivine (1-8%, 2-3 mm), and clinopyroxene (0-20%, 2-3 mm) in intersertal to intergranular groundmasses. Whole rock 40Ar/39Ar mean age of basalt is 1.41 +/- 0.04 Ma. |
| Sample Location: |
