DOI: 10.1016/j.quascirev.2012.11.035
Scopus记录号: 2-s2.0-84873271546
论文题名: The Palisades is a key reference site for the middle Pleistocene of eastern Beringia: New evidence from paleomagnetics and regional tephrostratigraphy
作者: Jensen B.J.L. ; Reyes A.V. ; Froese D.G. ; Stone D.B.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 63 起始页码: 91
结束页码: 108
语种: 英语
英文关键词: Alaska
; Eastern Beringia
; Loess
; Middle Pleistocene
; Paleomagnetic stratigraphy
; Tephrostratigraphy
Scopus关键词: Alaska
; Eastern Beringia
; Loess
; Paleomagnetic stratigraphy
; Pleistocene
; Tephrostratigraphy
; Forestry
; Isotopes
; Silt
; Sedimentology
; Beringia
; correlation
; documentary source
; Holocene
; loess
; paleomagnetism
; Pleistocene
; Quaternary
; sedimentation
; tephra
; Alaska
; Isotopes
; Loess
; Magnetic Properties
; Sediments
; Silt
; Alaska
; Bering Island
; Kamchatka
; Komandorski Islands
; Russian Federation
; United States
; Yukon River
英文摘要: The Palisades, in central Alaska, is one of the most prominent exposures of Quaternary sediments on the Yukon River. Perennially-frozen silt and sand at the Palisades are presently thought to preserve paleoenvironmental records from the Holocene to ~Marine Isotope Stage (MIS) 8 and, beneath a major unconformity, the earliest Pleistocene (~2 Ma). We present new paleomagnetic and tephrochronologic constraints that substantially revise the age of the sediments at the Palisades. We describe 15 new tephra beds, including five beds below the prominent PAL tephra that correlate to known tephra with independent age control from other sites in eastern Beringia. These five known tephra include Chester Bluff tephra, which is present in east-central Alaska and the Yukon, and the newly named Alyeska Pipeline and Taylor Highway tephra from central Alaska; all are constrained to the middle Pleistocene. Paleomagnetic transects from the base of the bluff to the MIS 5e forest bed yield normal polarity, with the exception of a brief reversal event between Old Crow tephra (124 ± 10 ka) and the MIS 5e forest bed that is likely the first documentation of the Blake paleomagnetic event in Alaskan loess. The detailed tephrostratigraphy and paleomagnetic data collectively suggest that most of the sedimentary record at the Palisades is middle Pleistocene in age. The Palisades thus preserves a rare record of late to middle Pleistocene paleoenvironments with multiple regionally distributed tephra beds. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60704
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, AB T6G 2E3, Canada; Geophysical Institute, University of Alaska, Fairbanks, AK, United States; School of Geography Archaeology, and Palaeoecology, Queen's University Belfast, Belfast, United Kingdom
Recommended Citation:
Jensen B.J.L.,Reyes A.V.,Froese D.G.,et al. The Palisades is a key reference site for the middle Pleistocene of eastern Beringia: New evidence from paleomagnetics and regional tephrostratigraphy[J]. Quaternary Science Reviews,2013-01-01,63