DOI: 10.1016/j.epsl.2018.03.002
Scopus记录号: 2-s2.0-85044460208
论文题名: Recycled Archean sulfur in the mantle wedge of the Mariana Forearc and microbial sulfate reduction within an extremely alkaline serpentine seamount
作者: Aoyama S. ; Nishizawa M. ; Miyazaki J. ; Shibuya T. ; Ueno Y. ; Takai K.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 491 起始页码: 109
结束页码: 120
语种: 英语
英文关键词: Mariana Forearc
; microbial sulfate reduction
; mud volcano
; multiple sulfur isotopes
; nitrogen isotopes
; serpentinization
Scopus关键词: Alkalinity
; Density measurement (specific gravity)
; Isotopes
; Magnesite
; Microorganisms
; Reduction
; Serpentine
; Silicate minerals
; Submarine geology
; Upper atmosphere
; Volcanoes
; Water
; Water recycling
; Forearc
; Mud volcanoes
; Multiple sulfur isotopes
; Nitrogen isotopes
; Serpentinization
; Sulfate reduction
; Sulfate minerals
; Archean
; mud volcano
; nitrogen isotope
; seamount
; serpentinization
; sulfate-reducing bacterium
; sulfur isotope
; upper mantle
; Mariana Arc
; Pacific Ocean
英文摘要: The identification of microbial activity under extreme conditions is important to define potential boundaries of the habitable and uninhabitable zones of terrestrial and extraterrestrial living forms. The subseafloor regimes of serpentinite seamounts in the Mariana Forearc are among the most extreme environments for life on earth owing to the widespread presence of highly alkaline fluids with pH values greater than 12. The potential activity of sulfate-reducing microorganisms has been suggested within the South Chamorro serpentinite seamounts on the basis of depletion of sulfate and enrichment of dissolved sulfide in pore water. However, the vertical distribution of sulfate-reducing microorganisms and the origin of sulfate are still uncertain. To address these issues, we analyzed quadruple sulfur isotopes of sulfide minerals and pore water sulfate in the upper 56 m of sedimentary sequences at the summit of the S. Chamorro Seamount and those of dissolved sulfate in upwelling fluids collected as deep as 202 mbsf (meters below the seafloor) in a cased hole near the summit of the same seamount. The depth profiles of the concentrations and the δ34S and Δ33S′ values of sulfide minerals and pore water sulfate indicate microbial sulfate reduction as deep as 30 mbsf. Further, apparent isotopic fractionations (ε34) and exponents of mass dependent relationships (λ33) during sulfate reduction are estimated to be 62 ± 14‰ and 0.512 ± 0.002, respectively. The upwelling fluids show both the chlorine depletion relative to seawater and the negative δ15N values of ammonia (−4‰). Although these signatures point to dehydration of the subducting oceanic plate, the negative Δ33S′ values of sulfate (−0.16‰ to −0.26‰ with analytical errors of ±0.01‰) are unlikely to originate from surrounding modern crusts. Instead, sulfate in the upwelling fluid likely possess non-mass-dependent (NMD) sulfur. Because NMD sulfur was produced primarily in the Archean atmosphere, our results suggest that the presence of recycled Archean crust that could be incorporated into the upper mantle through subduction of Archean oceanic crusts or from the NMD-bearing OIB seamounts located in the southern margin of the Pacific Plate. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109912
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo, 152-8551, Japan; Department of Subsurface Geobiological Analysis and Research (D-SUGAR), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushima-cho, Yokosuka, 237-0061, Japan; Research and Development (R&D) Center for Submarine Resources, JAMSTEC, Yokosuka, 237-0061, Japan; Project Team for Development of New-generation Research Protocol for Submarine Resources, JAMSTEC, Yokosuka, 237-0061, Japan; Earth-Life Science Institute (WPI-ELSI), Tokyo Institute of Technology, Meguro, Tokyo, 152-8550, Japan
Recommended Citation:
Aoyama S.,Nishizawa M.,Miyazaki J.,et al. Recycled Archean sulfur in the mantle wedge of the Mariana Forearc and microbial sulfate reduction within an extremely alkaline serpentine seamount[J]. Earth and Planetary Science Letters,2018-01-01,491