SCSIO OpenIR  > 中科院边缘海地质重点实验室
Triple sulfur isotope relationships during sulfate-driven anaerobic oxidation of methane
Gong, Shanggui6; Peng, Yongbo1; Bao, Huiming1; Feng, Dong2; Cao, Xiaobin1; Crockford, Peter W.; Chen, Duofu5
AbstractSulfate-driven anaerobic oxidation of methane (SD-AOM) plays a critical role in regulating the global methane budget. Determination of the diagnostic triple isotope exponent (33)theta ( In-33 alpha/ln(34) alpha) for SD-AOM can help to identify and quantify microbial sulfate reduction via SD-AOM in the environment. The history of Earth's surface redox conditions can also be examined through the measurement of triple sulfur isotope compositions in sedimentary rocks. Due to difficulties in both culturing anaerobic methanotrophs and sampling pore-water sulfate in SD-AOM-dominated environments, however, the (33)theta values for the processes of SD-AOM have not been constrained. We propose that a set of modern cold-seep associated barite samples with low Delta delta O-18/Delta delta S-34 values bear a record of residual pore-water sulfate during SD-AOM, and therefore the triple sulfur isotope composition of these barites can be used to deduce (33)theta values. We applied a 1-D diagenetic reaction-transport model to fit Delta S-33 and delta'S-34 results from modern cold seep barites collected from five sites in the Gulf of Mexico. Based on revealed negative correlations (R-2 = 0.77) between Delta S-33 and delta'S-34 values we calculated an upper-limit (33)theta value of 0.5100 to 0.5112 (+/- 0.0005) given a 1000In(34)alpha value of -30 parts per thousand to -10 parts per thousand. This (33)theta value is distinctively lower than that of organoclastic sulfate reduction (OSR) in marine environments where the diagnostic isotope fractionation (1000In(34)alpha) is typically more negative than that of SD-AOM. In addition, cold seep barite data display a negative Delta S-33-delta'S-34 correlation whereas pore-water sulfates of all OSR-dominated settings show a positive one. Therefore, the diagnostic triple-sulfur isotope exponent and associated negative Delta S-33-delta'S-34 correlation may allow for the identification of SD-AOM in sedimentary records. (C) 2018 Elsevier B.V. All rights reserved.
Keywordisotope fractionation reaction-transport model cold seeps barite anaerobic methane oxidation Gulf of Mexico multiple sulfur isotopes
Citation statistics
Cited Times:5[WOS]   [WOS Record]     [Related Records in WOS]
Document Type期刊论文
Affiliation1.Chinese Acad Sci, South China Sea Inst Oceanol, CAS Key Lab Ocean & Marginal Sea Geol, Guangzhou 510301, Guangdong, Peoples R China
2.Louisiana State Univ, Dept Geol & Geophys, Baton Rouge, LA 70803 USA
3.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Mineral Resources, Qingdao 266071, Peoples R China
4.Crockford, Peter W.] Weizmann Inst Sci, Dept Earth & Planetary Sci, Rehovot, Israel
5.Crockford, Peter W.] Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA
6.Shanghai Ocean Univ, Coll Marine Sci, Hadal Sci & Technol Res Ctr, Shanghai 201306, Peoples R China
7.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
Recommended Citation
GB/T 7714
Gong, Shanggui,Peng, Yongbo,Bao, Huiming,et al. Triple sulfur isotope relationships during sulfate-driven anaerobic oxidation of methane[J]. EARTH AND PLANETARY SCIENCE LETTERS,2018,504:13, 20.
APA Gong, Shanggui.,Peng, Yongbo.,Bao, Huiming.,Feng, Dong.,Cao, Xiaobin.,...&Chen, Duofu.(2018).Triple sulfur isotope relationships during sulfate-driven anaerobic oxidation of methane.EARTH AND PLANETARY SCIENCE LETTERS,504,13.
MLA Gong, Shanggui,et al."Triple sulfur isotope relationships during sulfate-driven anaerobic oxidation of methane".EARTH AND PLANETARY SCIENCE LETTERS 504(2018):13.
Files in This Item:
File Name/Size DocType Version Access License
Triple sulfur isotop(662KB)期刊论文出版稿开放获取CC BY-NC-SAApplication Full Text
Related Services
Recommend this item
Usage statistics
Export to Endnote
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.