| DOI: | 10.1016/j.quascirev.2018.12.026
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| Scopus记录号: | 2-s2.0-85060924196
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| 论文题名: | On the eruption age and provenance of the Old Crow tephra |
| 作者: | Burgess S.D.; Coble M.A.; Vazquez J.A.; Coombs M.L.; Wallace K.L.
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| 刊名: | Quaternary Science Reviews
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| ISSN: | 2773791
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| 出版年: | 2019
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| 卷: | 207 | | 起始页码: | 64
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| 结束页码: | 79
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| 语种: | 英语
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| 英文关键词: | (U–Th)/He
; Beringia
; Geochronlology
; Marine isotope stage
; Old Crow
; Tephrochronology
; Thermochronology
; U/Pb
; U/Th
; Zircon
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| Scopus关键词: | Geochemistry
; Geochronology
; Isotopes
; Silicate minerals
; Stratigraphy
; Beringia
; Geochronlology
; Marine isotope stages
; Old Crow
; Tephrochronology
; Thermochronology
; Zircon
; Beringia
; crystallization
; geochronology
; marine isotope stage
; Pleistocene
; Proterozoic
; provenance
; tephra
; tephrochronology
; titanomagnetite
; zircon
; Canada
; Old Crow
; Yukon Territory
|
| 英文摘要: | Tephrochronology is used to correlate and reconstruct geographically disparate sedimentary records of changing environment, climate, and landscape throughout geologic time. Single tephra layers represent isochronous markers across broad regions, thus accurate and precise radiometric constraints on the timing of eruption are critical to their utility. The Old Crow tephra is found throughout eastern Beringia and represents the largest preserved Pleistocene ashfall event in the region. Despite its volume and significance as a stratigraphic marker, the provenance of this tephra is debated, and the interpreted eruption age of marine isotope stage (MIS) 5 at ∼125 ka has vacillated. To investigate provenance and eruption age, we develop a geochemical fingerprint for the Old Crow tephra via titanomagnetite geochemistry, and zircon crystallization/cooling age via coupled U/Pb, U/Th, and (U–Th)/He zircon geochronology. Our results indicate that Old Crow oxides are geochemically distinct from the commonly assumed source-caldera system at the Emmons Lake Volcanic Center (ELVC). Zircon crystals from the Old Crow tephra range in age from Proterozoic to Pleistocene, with concordant zircon U/Pb, U/Th, and (U–Th)/He dates on the youngest population of grains suggesting crystallization in their parent magma, and in turn eruption, at 202.9 ± 9.5 ka. We discuss strengths and shortcomings of our radiogenic datasets in light of this result and review the far-reaching implications of a change in Old Crow eruption age. © 2018 |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/117375
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| Appears in Collections: | 气候变化与战略
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| Recommended Citation: | |
Burgess S.D.,Coble M.A.,Vazquez J.A.,et al. On the eruption age and provenance of the Old Crow tephra[J]. Quaternary Science Reviews,2019-01-01,207
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