DOI: 10.1016/j.epsl.2018.04.061
Scopus记录号: 2-s2.0-85047184660
论文题名: Nickel and its isotopes in organic-rich sediments: implications for oceanic budgets and a potential record of ancient seawater
作者: Ciscato E.R. ; Bontognali T.R.R. ; Vance D.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 494 起始页码: 239
结束页码: 250
语种: 英语
英文关键词: authigenic enrichment
; Lagoa Salgada
; nickel
; nickel isotopes
; organic-rich sediment
; Peru Margin
Scopus关键词: Budget control
; Isotopes
; Nickel
; Oceanography
; Organic carbon
; Seawater
; Sediments
; Sulfur compounds
; Transition metals
; Authigenic
; Lagoa Salgada
; Nickel isotopes
; Organic-rich sediment
; Peru margin
; Nickel compounds
英文摘要: Nickel (Ni) is a biologically active element that displays a nutrient-like depth distribution in the modern oceans. Recent studies of Ni isotopes have highlighted the fact that, in common with many other transition metals, the Ni stable isotope composition, expressed as δ60Ni, of the dissolved phase is heavier than the inputs, at +1.3 to +1.7‰. The sedimentary outputs that control the high δ60Ni of the ocean, coupled with records for past seawater, could potentially yield new information on the past Earth system, but these are currently not well understood. Here we present the first Ni abundance and isotope data for a key output, that associated with Ni uptake into organic matter, at productive upwelling regions and elsewhere. We investigate the distribution of Ni and its isotopes in two fractions separated from the bulk sediment, an HF-digestible fraction, extracted with HF–HCl, and an organic-sulphide-rich fraction. The organic-sulphide fractions exhibit a range in δ60Ni, from +0.86 to +1.83. Systematic relationships between Ni concentrations, total organic carbon and Ni isotopes suggest that the organic-sulphide fraction originates in the photic zone, and is delivered to the sediment as a closed system, despite the possibility of transfer of Ni to sulphide within it. Authigenic Ni in the bulk sediment is dominated by the HF-digestible fraction which, in Ni-enriched sediments where the detrital correction is small, is very close to the modern deep ocean, at δ60Ni = +1.2‰. These data suggest that organic-rich sediments beneath upwelling zones, while they are an important output flux of Ni from the oceans, do not solve the isotope balance problem because their δ60Ni is almost identical to modern seawater. On the other hand, the approach adopted here involving the analysis of the two fractions, both traces the fractionation imparted by biological uptake as well as recording the δ60Ni of contemporary seawater, suggesting potential for understanding the past oceans. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109840
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
There are no files associated with this item.
作者单位: Institute of Geochemistry and Petrology, Department of Earth Sciences, ETH Zürich, Clausiusstrasse 25, Zürich, 8092, Switzerland; Space-X, Fbg de l'Hôpital 68, Neuchâtel, 2000, Switzerland
Recommended Citation:
Ciscato E.R.,Bontognali T.R.R.,Vance D.. Nickel and its isotopes in organic-rich sediments: implications for oceanic budgets and a potential record of ancient seawater[J]. Earth and Planetary Science Letters,2018-01-01,494