DOI: 10.1016/j.quascirev.2013.10.020
Scopus记录号: 2-s2.0-84887357506
论文题名: A Pb isotope tracer of ocean-ice sheet interaction: The record from the NE Atlantic during the Last Glacial/Interglacial cycle
作者: Crocket K.C. ; Foster G.L. ; Vance D. ; Richards D.A. ; Tranter M.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 82 起始页码: 133
结束页码: 144
语种: 英语
英文关键词: Authigenic and pre-formed FeMn oxyhydroxides
; British-Irish Ice Sheet (BIIS)
; Chemical weathering
; Glacial/interglacial cycles
; Last Glacial Maximum
; Pb isotopes
Scopus关键词: Carbon dioxide
; Feedback
; Glacial geology
; Glaciers
; Isotopes
; Submarine geology
; Weathering
; Authigenic and pre-formed FeMn oxyhydroxides
; British-Irish ice sheet
; Chemical weathering
; Glacial/interglacial cycles
; Last Glacial Maximum
; Pb isotopes
; Lead
; accuracy assessment
; cyclicity
; glacial-interglacial cycle
; ice sheet
; ice-ocean interaction
; Last Glacial
; lead isotope
; subglacial environment
; Atlantic Ocean
; Atlantic Ocean (Northeast)
英文摘要: Ice sheet-ocean interactions are both a response to climate forcing and a source of climate feedback, releasing freshwater to the surface ocean and influencing climate and atmospheric CO2 through changes in ocean circulation. Documenting the outcomes of these interactions for recent glacial cycles is important given current and future scenarios of polar ice retreat. However, this is currently hampered by lack of accurate constraints on ice sheet development and demise. Marine sedimentary Pb isotope records have potential to investigate these aspects of ice sheet feedbacks at high temporal resolution because of the sensitivity of the Pb isotope composition to continental weathering intensity and solute flux. Here we present a Pb isotope record sourced from the FeMn oxyhydroxide fraction in marine sediments from ODP Site 980 on Feni Drift (2168mbsl, Rockall Trough, NE Atlantic), spanning the last 43ka. The location of Site 980 at the northern edge of the British-Irish Ice Sheet (BIIS) makes it well-placed to monitor changes in BIIS development as it responded to migration of the Polar Front during the Last Glacial/Interglacial cycle. The data reveal millennial-scale cyclicity in Pb isotope composition, reminiscent of Dansgaard-Oeschger cycles, from the start of the record until Heinrich event 2 (43-24ka), characterised by extreme shifts to radiogenic compositions (i.e. variation in 206Pb/204Pb from ~18.9 to 20.5). The period 24-17.5ka is also characterised by exceptionally radiogenic and highly variable Pb isotope compositions, associated with the rapid and repeated expansion and collapse of the BIIS. The presence of such radiogenic Pb isotope compositions during periods of maximum ice sheet activity support interpretation of the subglacial environment as an active weathering environment, contributing to biogeochemical cycles through the transport vectors of meltwater release and debris-laden ice calving. © 2013 The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60434
Appears in Collections: 过去全球变化的重建
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作者单位: Bristol Isotope Group, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, United Kingdom; Bristol Isotope Group, Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, United Kingdom; Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol BS8 1SS, United Kingdom; Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Waterfront Campus, Southampton SO14 3ZH, United Kingdom; Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zürich, NW D81.4, Clausiusstrasse 25, 8092 Zürich, Switzerland
Recommended Citation:
Crocket K.C.,Foster G.L.,Vance D.,et al. A Pb isotope tracer of ocean-ice sheet interaction: The record from the NE Atlantic during the Last Glacial/Interglacial cycle[J]. Quaternary Science Reviews,2013-01-01,82