Sample: 87-ARh-30
| Sample ID: | 87-ARh-30 [1] |
| Station ID: | 87-ARh-30 |
| AT Num: | |
| Volcano: | Sanford |
| Possible source: | |
| Eruption: | |
| Collector: | Richter, D. H. |
| Date sampled: | 1987-00-00 |
| Sample type 1: | Lava |
| Color: | |
| Final unit: | |
| Text Description: | Mount Sanford Dacite flows (Pleistocene). Massive, light- to medium-light-gray, conspicuously porphyritic dacite flows on west and southeast flanks of Mount Sanford. Flow on west flank contains phenocrysts of plagioclase (4-6%, 1-2 mm), hornblende (2-3%, 1 mm; mostly altered to opaque minerals), and opaque minerals (trace), in trachytic to cryptocrystalline groundmass. Flow fills pronounced topographic low that is possibly along postulated caldera wall; maximum thickness about 500 m. Flow on southeast flank is coarsely porphyritic, containing phenocrysts of plagioclase (15-20%, as large as 1 cm), clinopyroxene (1-3%, 1-2 mm), opaque minerals (1%), and biotite (trace), in microfelty groundmass that consists chiefly of feldspar. Maximum thickness about 150 m. |
| Sample Location: |