DOI: 10.1111/gbi.12247
Scopus记录号: 2-s2.0-85027542859
论文题名: Benthic iron cycling in a high-oxygen environment: Implications for interpreting the Archean sedimentary iron isotope record
作者: McCoy V.E. ; Asael D. ; Planavsky N.
刊名: Geobiology
ISSN: 1472-4677
EISSN: 1472-4669
出版年: 2017
卷: 15, 期: 5 起始页码: 619
结束页码: 627
语种: 英语
Scopus关键词: Bacteria (microorganisms)
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 most notable trend in the sedimentary iron isotope record is a shift at the end of the Archean from highly variable δ56Fe values with large negative excursions to less variable δ56Fe values with more limited negative values. The mechanistic explanation behind this trend has been extensively debated, with two main competing hypotheses: (i) a shift in marine redox conditions and the transition to quantitative iron oxidation; and (ii) a decrease in the signature of microbial iron reduction in the sedimentary record because of increased bacterial sulfate reduction (BSR). Here, we provide new insights into this debate and attempt to assess these two hypotheses by analyzing the iron isotope composition of siderite concretions from the Carboniferous Mazon Creek fossil site. These concretions precipitated in an environment with water column oxygenation, extensive sediment pile dissimilatory iron reduction (DIR) but limited bacterial sulfate reduction (BSR). Most of the concretions have slightly positive iron isotope values, with a mean of 0.15‰ and limited iron isotope variability compared to the Archean sedimentary record. This limited variability in an environment with high DIR and low BSR suggests that these conditions alone are insufficient to explain Archean iron isotope compositions. Therefore, these results support the idea that the unusually variable and negative iron isotope values in the Archean are due to dissimilatory iron reduction (DIR) coupled with extensive water column iron cycling. © 2017 John Wiley & Sons Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/85039
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Geology, University of Leicester, Leicester, United Kingdom; Department of Geology and Geophysics, Yale University, New Haven, CT, United States
Recommended Citation:
McCoy V.E.,Asael D.,Planavsky N.. Benthic iron cycling in a high-oxygen environment: Implications for interpreting the Archean sedimentary iron isotope record[J]. Geobiology,2017-01-01,15(5)