DOI: 10.1016/j.gloplacha.2016.03.004
论文题名: Microbial sulfur metabolism evidenced from pore fluid isotope geochemistry at Site U1385
作者: Turchyn A.V. ; Antler G. ; Byrne D. ; Miller M. ; Hodell D.A.
刊名: Global and Planetary Change
ISSN: 0921-8181
出版年: 2015
卷: 141 起始页码: 82
结束页码: 90
语种: 英语
英文关键词: Microbial sulfate reduction
; Oxygen isotope
; Pyrite
; Sulfur isotope
Scopus关键词: Anaerobic digestion
; Diffusion in liquids
; Dissolved oxygen
; Exploratory geochemistry
; Iron
; Isotopes
; Methane
; Oxidation
; Oxygen
; Pyrites
; Sediments
; Sulfur
; Water
; Anaerobic methane oxidations
; Isotope fractionation
; Isotope geochemistry
; Oxygen isotope ratios
; Oxygen isotopes
; Sulfate concentrations
; Sulfate reduction
; Sulfur isotope
; Sulfur compounds
; bacterium
; concentration (composition)
; isotopic analysis
; marine sediment
; metabolism
; microbial activity
; oxygen isotope
; porewater
; pyrite
; reduction
; seafloor
; sediment chemistry
; sulfate-reducing bacterium
; sulfur isotope
; Portugal
; Bacteria (microorganisms)
英文摘要: At Site U1385, drilled during IODP Expedition 339 off the coast of Portugal on the continental slope, high-resolution sulfate concentration measurements in the pore fluids display non-steady-state behavior. At this site there is a zone of sulfate reduction in the uppermost seven meters of sediment, followed by a 38-meter interval where sulfate concentrations do not change, and finally sulfate concentrations are depleted to zero between 45 and 55 meters below seafloor. Below the sulfate minimum zone, there is abundant methane, suggesting that the lower sulfate consumption zone is coupled to anaerobic methane oxidation. We analyze pore water samples from IODP Site U1385 for sulfur and oxygen isotope ratios of dissolved sulfate, as well as the sulfur isotope composition of sedimentary pyrite. The sulfur isotopes in pore fluid sulfate display similar non-steady-state behavior similar to that of the sulfate concentrations, increasing over the uppermost zone of sulfate reduction and again over the lower zone of sulfate-driven anaerobic methane oxidation. The oxygen isotopes in sulfate increase to the ‘apparent equilibrium’ value in the uppermost zone of sulfate reduction and do not change further. Our calculations support the idea that sulfite to sulfide reduction is the limiting step in microbial sulfate reduction, and that the isotope fractionation expressed in the residual pore water sulfate pool is inversely proportional to the net sulfate reduction rate. The sulfur isotope composition of pyrite acquires one value in the uppermost sediments, which may be overprinted by a second value in the deeper sediments, possibly due to iron release during anaerobic methane oxidation or iron diffusion from a higher zone of bacterial iron reduction. Our results have implications for modeling the sulfur isotope composition of the pyrite burial flux in the global biogeochemical sulfur cycle. © 2016 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961933612&doi=10.1016%2fj.gloplacha.2016.03.004&partnerID=40&md5=d8971f036a87541b1f77000dae516462
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11560
Appears in Collections: 全球变化的国际研究计划 气候变化与战略
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作者单位: Department of Earth Sciences, University of Cambridge, Cambridge, United Kingdom
Recommended Citation:
Turchyn A.V.,Antler G.,Byrne D.,et al. Microbial sulfur metabolism evidenced from pore fluid isotope geochemistry at Site U1385[J]. Global and Planetary Change,2015-01-01,141.