DOI: 10.1016/j.epsl.2017.10.019
Scopus记录号: 2-s2.0-85033553382
论文题名: Controls on the barium isotope compositions of marine sediments
作者: Bridgestock L. ; Hsieh Y.-T. ; Porcelli D. ; Homoky W.B. ; Bryan A. ; Henderson G.M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 481 起始页码: 101
结束页码: 110
语种: 英语
英文关键词: barium isotopes
; GEOTRACES
; marine barium cycle
; marine sediments
; paleo-oceanography
Scopus关键词: Barium
; Isotopes
; Marine applications
; Sedimentology
; Submarine geology
; GEOTRACES
; Isotope compositions
; Isotopic fractionations
; marine barium cycle
; Marine sediments
; Mass accumulation rates
; Relative contribution
; Upper water column
; Sediments
; accumulation rate
; barium
; isotopic composition
; isotopic fractionation
; marine sediment
; paleoceanography
; sediment chemistry
; water column
英文摘要: The accumulation of barium (Ba) in marine sediments is considered to be a robust proxy for export production, although this application can be limited by uncertainty in BaSO4 preservation and sediment mass accumulation rates. The Ba isotope compositions of marine sediments could potentially record insights into past changes in the marine Ba cycle, which should be insensitive to these limitations, enabling more robust interpretation of sedimentary Ba as a proxy. To investigate the controls on the Ba isotope compositions of marine sediments and their potential for paleo-oceanographic applications, we present the first Ba isotope compositions results for sediments, as well as overlying seawater depth profiles collected in the South Atlantic. Variations in Ba isotope compositions of the sediments predominantly reflect changes in the relative contributions of detrital and authigenic Ba sources, with open-ocean sediments constraining the isotope composition of authigenic Ba to be δBa138/134≈+0.1‰. This value is consistent with the average isotope composition inferred for sinking particulate Ba using simple mass balance models of Ba in the overlying water column and is hypothesized to reflect the removal of Ba from the upper water column with an associated isotopic fractionation of ΔBadiss-part138/134≈+0.4 to +0.5. Perturbations to upper ocean Ba cycling, due to changes in export production and the supply of Ba via upwelling, should therefore be recorded by the isotope compositions of sedimentary authigenic Ba. Such insights will help to improve the reliable application of Ba accumulation rates in marine sediments as a proxy for past changes in export production. © 2017 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110173
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, United Kingdom
Recommended Citation:
Bridgestock L.,Hsieh Y.-T.,Porcelli D.,et al. Controls on the barium isotope compositions of marine sediments[J]. Earth and Planetary Science Letters,2018-01-01,481