Sample: 91CND28
| Sample ID: | 91CND28 [1] |
| Station ID: | 91CND28 |
| AT Num: | |
| Volcano: | Douglas |
| Possible source: | |
| Eruption: | |
| Collector: | Nye, C. J. |
| Date sampled: | 1991-01-01 |
| Sample type 1: | Lava |
| Color: | |
| Final unit: | |
| Text Description: | Sample from tongue of lava flows 2.4 wide by 4.5 km long, and from seven to twelve kilometers from the summit. These lavas overlie sedimentary country-rock at elevations as high as 1700 feet. Porphyritic two-pyroxene andesite. Phenocrysts of plagioclase (10%, up to 1.5 x 0.5 mm) and pyroxene (10%, stubby prisms up to 0.5 mm in diameter), and glomerocrysts of plagioclase and pyroxene (5%, up to 1 mm in diameter, often with masses of wormy opaques in the center) up to up to 0.4 x 0.2 mm) in a groundmass of devitrified glass and subordinate coarse microphenocrysts and microlites. Most plagioclase crystals have well developed sieve textures either throughout or in broad concentric zones. |
| Sample Location: |
