Sample: ACT-1916
| Sample ID: | ACT-1916 [1] |
| Station ID: | Beget_2003_Moose_Creek |
| AT Num: | |
| Volcano: | |
| Possible source: | |
| Eruption: | Old Crow Tephra |
| Collector: | Beget, J. E. |
| Date sampled: | |
| Sample type 1: | Tephra Fall |
| Color: | |
| Final unit: | |
| Text Description: | 20 to 30 cm thick tephra bed that could be traced for more than 30 m along the trend of the trench. The ash layer in the exposure was not mixed with the surrounding loess or other sediment, and the contact between the tephra and the underlying loess was sharp. Glass shards in the tephra are angular and fresh-appearing. The ash's physical characteristics, together with its lateral continuity across the 30-m-long outcrop, indicate that it is a primary ashfall deposit. Petrographic examination of the tephra shows that it is composed primarily of clear, platey glass shards, together with many “Y”-shaped shards. Very few phenocrysts were present, but crystals of feldspar, orthopyroxene, and clinopyroxene were identified in grain mounts. |
| Sample Location: |