Sample: 91CNI01
| Sample ID: | 91CNI01 [1] |
| Station ID: | 91CNI01 |
| AT Num: | |
| Volcano: | Iliamna |
| Possible source: | |
| Eruption: | |
| Collector: | Nye, C. J. |
| Date sampled: | 1991-01-01 |
| Sample type 1: | Lava |
| Color: | |
| Final unit: | |
| Text Description: | Porphyritic two-pyroxene low-silica andesite. Phenocrysts of plagioclase (35%, up to 1.7 mm), clinopyroxene (20%, typically 0.5 mm diameter stubby prisms), and orthopyroxene (5%). Groundmass consists of abundant microlites (typically < 20 microns) with subordinate deep reddish-brown glass. Most plagioclase phenocrysts are extensively sieved. 91CNI01, 07, and 12 are petrographically similar to each other, and different from typical Iliamna lavas in this suite in their strongly colored glass and extensive sieving of plagioclase. One of several diverse lithologies collected from single location consisting of avalanche debris sitting on top of Red Glacier at ~2400 foot elevation. This location is at a fork in the glacier, and these samples could have come from either the main cone or North Twin. This location covered by subsequent rock/snow/ice avalanches (seen in landsat image on GE). "i" denotes fist-sized rounded blobs of macroscopically different magma enclosed in homogeneous host. |
| Sample Location: |
