DOI: 10.1111/gbi.12198
Scopus记录号: 2-s2.0-84978219601
论文题名: Chromium isotopic composition of core-top planktonic foraminifera
作者: Wang X.L. ; Planavsky N.J. ; Hull P.M. ; Tripati A.E. ; Zou H.J. ; Elder L. ; Henehan M.
刊名: Geobiology
ISSN: 1472-4677
EISSN: 1472-4669
出版年: 2017
卷: 15, 期: 1 起始页码: 51
结束页码: 64
语种: 英语
Scopus关键词: atmosphere-ocean system
; calcite
; carbonate
; geological record
; heterogeneity
; isotopic composition
; isotopic fractionation
; mixed layer
; planktonic foraminifera
; seawater
; thermocline
; water column
; Foraminifera
; chromium
; sea water
; aquatic species
; chemistry
; foraminifer
; parasitology
; plankton
; Aquatic Organisms
; Chromium Isotopes
; Foraminifera
; Plankton
; Seawater
Scopus学科分类: Earth and Planetary Sciences: General Earth and Planetary Sciences
; Environmental Science: General Environmental Science
; Agricultural and Biological Sciences: Ecology, Evolution, Behavior and Systematic
英文摘要: The chromium isotope system (53Cr/52Cr expressed as δ53Cr relative to NIST SRM 979) is potentially a powerful proxy for the redox state of the ocean–atmosphere system, but a lack of temporally continuous, well-calibrated archives has limited its application to date. Marine carbonates could potentially serve as a common and continuous Cr isotope archive. Here, we present the first evaluation of planktonic foraminiferal calcite as an archive of seawater δ53Cr. We show that single foraminiferal species from globally distributed core tops yielded variable δ53Cr, ranging from 0.1‰ to 2.5‰. These values do not match with the existing measurements of seawater δ53Cr. Further, within a single core-top, species with similar water column distributions (i.e., depth habitats) yielded variable δ53Cr values. In addition, mixed layer and thermocline species do not consistently exhibit decreasing trends in δ53Cr as expected based on current understanding of Cr cycling in the ocean. These observations suggest that either seawater δ53Cr is more heterogeneous than previously thought or that there is significant and species-dependent Cr isotope fractionation during foraminiferal calcification. Given that the δ53Cr variability is comparable to that observed in geological samples throughout Earth's history, interpreting planktonic foraminiferal δ53Cr without calibrating modern foraminifera further, and without additional seawater measurements, would lead to erroneous conclusions. Our core-top survey clearly indicates that planktonic foraminifera are not a straightforward δ53Cr archive and should not be used to study marine redox evolution without additional study. It likewise cautions against the use of δ53Cr in bulk carbonate or other biogenic archives pending further work on vital effects and the geographic heterogeneity of the Cr isotope composition of seawater. © 2016 John Wiley & Sons Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/85083
Appears in Collections: 影响、适应和脆弱性
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作者单位: Yale University, New Haven, CT, United States; University of California, Los Angeles, CA, United States; Université de Brest, Plouzané, France
Recommended Citation:
Wang X.L.,Planavsky N.J.,Hull P.M.,et al. Chromium isotopic composition of core-top planktonic foraminifera[J]. Geobiology,2017-01-01,15(1)