Sample: Riehle_1987_11b
| Sample ID: | Riehle_1987_11b [1] |
| Station ID: | Riehle_1987_11 |
| AT Num: | |
| Volcano: | Yantarni |
| Possible source: | |
| Eruption: | |
| Collector: | Unknown, Unknown |
| Date sampled: | |
| Sample type 1: | pyroclastic density current |
| Color: | |
| Final unit: | |
| Text Description: | Sample of pyroclastic flow deposit that has 50% or more ash matrix, and on the basis of its granulometry is classified as an ash-flow tuff. Sample is representative only of the fine-grained matrix. Vesicular, porphyritic basaltic andesite with subhedral to euhedral phenocrysts of plagioclase, clino- and orthopyroxene, and hornblende in a fine-grained, holocrystalline groundmass. Hornblende also occurs in the groundmass and shows minor reaction rims of clinopyroxene but no opaque rims. (Texture: Vesicular vitrophyre; groundmass 0.2-0.4 mm, plagioclase > clinopyroxene = hornblende > opaque (orthopyroxene?); hornblende rimmed by clinopyroxene and plagioclase; rare glass. Alteration: None) |
| Sample Location: |
References Cited
[1] Petrography, chemistry, and geologic history of Yantarni volcano, Aleutian volcanic arc, Alaska, 1987
Riehle, J. R., Yount, M. E., and Miller, T. P., 1987, Petrography, chemistry, and geologic history of Yantarni volcano, Aleutian volcanic arc, Alaska: U.S. Geological Survey Bulletin 1761, 27 p., 1 sheet, scale 1:63,360.
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