气候变化领域集成服务门户(CCPortal): Multiple sulfur isotopes in methane seep carbonates track unsteady sulfur cycling during anaerobic methane oxidation

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DOI	10.1016/j.epsl.2019.115994
	Multiple sulfur isotopes in methane seep carbonates track unsteady sulfur cycling during anaerobic methane oxidation
	Crémière A.; Pellerin A.; Wing B.A.; Lepland A.
发表日期	2020
ISSN	0012821X
卷号	532
英文摘要	The anaerobic oxidation of methane coupled with sulfate reduction (AOM-SR) is a major microbially-mediated methane consuming process in marine sediments including methane seeps. The AOM-SR can lead to the formation of methane-derived authigenic carbonates which entrap sulfide minerals (pyrite) and carbonate-associated sulfate (CAS). We studied the sulfur isotope compositions of the pyrite and CAS in seafloor methane-derived authigenic carbonate crust samples from the North Sea and Barents Sea which reflect the time-integrated metabolic activity of the AOM-SR community as well as the physical conditions under which those carbonates are formed. In these samples, pyrite exhibits δ34S values ranging from −23.4‰ to 14.8‰ and Δ33S values between −0.06‰ and 0.16‰, whereas CAS is characterized by δ34S values ranging from 26.2‰ to 61.6‰ and Δ33S mostly between −0.05‰ and 0.07‰. Such CAS sulfur isotope compositions are distinctly lower in δ34S-Δ33S space from published porewater sulfate values from environments where the reduction of sulfate is mostly coupled to sedimentary organic matter oxidation. Mass-balance modelling suggests that (1) AOM-SR appears to cause rapid carbonate precipitation under high methane flux near or at the sediment-water interface and (2) that the precipitation of pyrite and carbonates are not necessarily synchronous. The sulfur isotopic composition of pyrite is interpreted to reflect more variable precipitating conditions of evolving sulfide with porewater connectivity, fluctuating methane fluxes and oxidative sulfur cycle. Taken together, the multiple isotopic compositions of pyrite and sulfate in methane-derived authigenic carbonates indicate protracted precipitation under conditions of non-steady state methane seepage activity. © 2019 Elsevier B.V.
关键词	anaerobic oxidation of methane methane-derived authigenic carbonates microbial sulfate reduction multiple sulfur isotopes pyrite and carbonate-associated sulfate
英文关键词	Carbonates; Carbonation; Isotopes; Oxidation; Pyrites; Submarine geology; Sulfate minerals; Anaerobic oxidation of methanes; Carbonate-associated sulfates; Methane-derived authigenic carbonates; Multiple sulfur isotopes; Sulfate reduction; Methane; carbonate sediment; hydrocarbon seep; methane; oxidation; precipitation (chemistry); pyrite; sulfate; sulfur cycle; sulfur isotope; Arctic Ocean; Atlantic Ocean; Barents Sea; North Sea
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202553
作者单位	Geological Survey of Norway, Trondheim, 7491, Norway; Centre for Arctic Gas Hydrate, Environment and Climate, University of Tromsø, Tromsø, 9037, Norway; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States; Center for Geomicrobiology, Department of Biological Sciences, Aarhus University, Ny Munkegade 114, Aarhus C, 8000, Denmark; Geological Sciences, University of Colorado Boulder, UCB 399, Boulder, CO 80309-0399, United States; Department of Geology, University of Tartu, Tartu, 50411, Estonia
推荐引用方式 GB/T 7714	Crémière A.,Pellerin A.,Wing B.A.,et al. Multiple sulfur isotopes in methane seep carbonates track unsteady sulfur cycling during anaerobic methane oxidation[J],2020,532.
APA	Crémière A.,Pellerin A.,Wing B.A.,&Lepland A..(2020).Multiple sulfur isotopes in methane seep carbonates track unsteady sulfur cycling during anaerobic methane oxidation.Earth and Planetary Science Letters,532.
MLA	Crémière A.,et al."Multiple sulfur isotopes in methane seep carbonates track unsteady sulfur cycling during anaerobic methane oxidation".Earth and Planetary Science Letters 532(2020).