Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, Alaska
<p>Multiple chronometers can be employed for dating Holocene palaeoenvironmental records, each with its own inherent strengths and weaknesses. Radiocarbon dating is one of the most widely used techniques for producing chronologies, but its application at high-latitude sites can sometimes be pr...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-03-01
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| Series: | Geochronology |
| Online Access: | https://gchron.copernicus.org/articles/4/121/2022/gchron-4-121-2022.pdf |
| _version_ | 1797229737371762688 |
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| author | L. J. Davies L. J. Davies B. J. L. Jensen D. S. Kaufman |
| author_facet | L. J. Davies L. J. Davies B. J. L. Jensen D. S. Kaufman |
| author_sort | L. J. Davies |
| collection | DOAJ |
| description | <p>Multiple chronometers can be employed for dating Holocene
palaeoenvironmental records, each with its own inherent strengths and
weaknesses. Radiocarbon dating is one of the most widely used techniques for
producing chronologies, but its application at high-latitude sites can
sometimes be problematic. Here, cryptotephra were identified in a core from
Cascade Lake, Arctic Alaska, and used to identify and resolve an age bias in
Late Holocene radiocarbon dates from the top 1.42 m of the sediment
sequence. Identifiable geochemical populations of cryptotephra are shown to
be present in detectable concentrations in sediment from the north flank of
the Brooks Range for the first time. Major-element glass geochemical
correlations are demonstrated between ultra-distal cryptotephra and
reference samples from the Late Holocene caldera-forming eruption of Opala,
Kamchatka, as well as three eruptions in North America: the White River Ash
(northern lobe), Ruppert tephra and the Late Holocene caldera-forming
eruption of Aniakchak. The correlated ages of these cryptotephra provide
evidence for an old-carbon effect and support preliminary palaeomagnetic
secular variation (PSV) correlated ages reported for Cascade Lake.
Chronological data from Cascade Lake were then combined using a Bayesian
approach to generate an age–depth model that extends back through the Late
Holocene and provisionally to 15 000 <span class="inline-formula">cal yr BP</span>.</p> |
| first_indexed | 2024-04-24T15:17:21Z |
| format | Article |
| id | doaj.art-a456708ffaa449e18a85d8500322e524 |
| institution | Directory Open Access Journal |
| issn | 2628-3719 |
| language | English |
| last_indexed | 2024-04-24T15:17:21Z |
| publishDate | 2022-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Geochronology |
| spelling | doaj.art-a456708ffaa449e18a85d8500322e5242024-04-02T09:13:18ZengCopernicus PublicationsGeochronology2628-37192022-03-01412114110.5194/gchron-4-121-2022Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, AlaskaL. J. Davies0L. J. Davies1B. J. L. Jensen2D. S. Kaufman3Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, CanadaDepartment of Geography, University of Cambridge, Cambridge, UKDepartment of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, CanadaSchool of Earth and Sustainability, Northern Arizona University, Flagstaff, Arizona, USA<p>Multiple chronometers can be employed for dating Holocene palaeoenvironmental records, each with its own inherent strengths and weaknesses. Radiocarbon dating is one of the most widely used techniques for producing chronologies, but its application at high-latitude sites can sometimes be problematic. Here, cryptotephra were identified in a core from Cascade Lake, Arctic Alaska, and used to identify and resolve an age bias in Late Holocene radiocarbon dates from the top 1.42 m of the sediment sequence. Identifiable geochemical populations of cryptotephra are shown to be present in detectable concentrations in sediment from the north flank of the Brooks Range for the first time. Major-element glass geochemical correlations are demonstrated between ultra-distal cryptotephra and reference samples from the Late Holocene caldera-forming eruption of Opala, Kamchatka, as well as three eruptions in North America: the White River Ash (northern lobe), Ruppert tephra and the Late Holocene caldera-forming eruption of Aniakchak. The correlated ages of these cryptotephra provide evidence for an old-carbon effect and support preliminary palaeomagnetic secular variation (PSV) correlated ages reported for Cascade Lake. Chronological data from Cascade Lake were then combined using a Bayesian approach to generate an age–depth model that extends back through the Late Holocene and provisionally to 15 000 <span class="inline-formula">cal yr BP</span>.</p>https://gchron.copernicus.org/articles/4/121/2022/gchron-4-121-2022.pdf |
| spellingShingle | L. J. Davies L. J. Davies B. J. L. Jensen D. S. Kaufman Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, Alaska Geochronology |
| title | Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, Alaska |
| title_full | Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, Alaska |
| title_fullStr | Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, Alaska |
| title_full_unstemmed | Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, Alaska |
| title_short | Late Holocene cryptotephra and a provisional 15 000-year Bayesian age model for Cascade Lake, Alaska |
| title_sort | late holocene cryptotephra and a provisional 15 thinsp 000 year bayesian age model for cascade lake alaska |
| url | https://gchron.copernicus.org/articles/4/121/2022/gchron-4-121-2022.pdf |
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