Sample: Jensen_2008_Chester_Bluff_Charley_River_tephra
| Sample ID: |
Jensen_2008_Chester_Bluff_Charley_River_tephra [1] [2] |
| Station ID: |
Jensen_2008_Chester_Bluff |
| AT Num: |
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| Volcano: |
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| Possible source: |
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| Eruption: |
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| Collector: |
Jensen, B. J. L. |
| Date sampled: |
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| Sample type 1: |
Tephra Fall |
| Color: |
orange-pink or white |
| Final unit: |
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| Text Description: |
Present at all three sites of Chester Bluff, Site A, Site B, and Site C. Lowermost tephra, found at all sites. It forms pods up to 4 cm thick and 10 cm long and tends to have an orange-pink cast when within organic sediments, although it can also be white. CR is reworked into, or directly above, fissile organic-rich silt. The lateral continuity of CR across the bluffs suggests that CR was deposited when the site was relatively level and loess had not aggraded and/or been incised enough to form a complex gully-bluff network like the one that is seen today. The different sequence of tephra beds above CR at each site suggests the presence of one or more unconformities above the tephra bed. Low percentage of phenocrysts (<20%) and contain a population of distinctively thick-walled pumice and glass shards. The composition reported was calculated from analyses of fourteen samples: UA1052, UA1053, UA1054, UA1064, UA1078, UA1092, UA1093, UA1094, UA1095, UT1878, UT1880, UT1889, UT1667, and UA1234. |
| Sample Location: |
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References Cited
Jensen, B.J.L., Froese, D.L., Preece, S.J., Westgate, J.A., and Stachel, Thomas, 2008, An extensive middle to late Pleistocene tephrochronologic record from east-central Alaska: Quaternary Science Reviews, v. 27, p. 411-427, doi:10.1016/j.quascirev.2007.10.010 .
Jensen, B.J.L., 2007, Tephrochronology of Middle to Late Pleistocene Loess in Eastcentral Alaska: University of Alberta M.S. thesis, 120 p.