Sample: Barth_1956_18
| Sample ID: | Barth_1956_18 [1] |
| Station ID: | Barth_1956_18 |
| AT Num: | |
| Volcano: | St. George volcanic field |
| Possible source: | |
| Eruption: | |
| Collector: | Barth, T. F. W. |
| Date sampled: | 1948-01-01 |
| Sample type 1: | Lava |
| Color: | dark |
| Final unit: | |
| Text Description: | Ore basalt, forming a sill or dike. To the eye and under a low power lens the rock appears dark and almost dense because of its unusually high percentage of ore. It is very fine grained with some odd, small phenocrysts of plagioclase (optical constants corresponding to An60), and a very few, small phenocrysts of olivine that are almost wholly resorbed and often obscured by tiny grains of ore (hematite?) which have grown along closely spaced cleavage planes. Some olivines have been effectively replaced by ore. The profusion of ore gives the rock its distinctive character. |
| Sample Location: |
References Cited
[1] Geology and petrology of the Pribilof Islands, Alaska, 1956
Barth, T. F. W., 1956, Geology and petrology of the Pribilof Islands, Alaska: in Investigations of Alaskan volcanoes, U.S. Geological Survey Bulletin 1028-F, p. 101-160, 2 sheets, scale unknown.
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