| Nonevaporative origin for gypsum in mud sediments from the East China Sea shelf | |
Liu, Xiting1,2; Li, Anchun3; Dong, Jiang3,4; Zhuang, Guangchao5; Xu, Fangjian6; Wan, Shiming3
| |
| 2018-09-20 | |
| 发表期刊 | MARINE CHEMISTRY
 |
| ISSN | 0304-4203 |
| 卷号 | 205页码:90-97 |
| 通讯作者 | Liu, Xiting([email protected]) ; Li, Anchun([email protected]) |
| 摘要 | Gypsum (CaSO4 center dot 2H(2)O) precipitated in nonevaporative marine environments is rarely reported, and the related diagenetic process and its implications for the sulfur cycle (e.g., sulfide reoxidation) are still not well known. We employ coupled sulfur and oxygen isotopes of authigenic gypsum, as well as sulfur isotopic compositions of pyrite, from core EC2005, which is drilled on the inner shelf of the East China Sea, to constrain the sulfur and oxygen sources for gypsum precipitation. The delta S-34(gypsum) values range from -24.8 to -12.2 parts per thousand, which are much more depleted in S-34 than modem seawater sulfate, suggesting additional S-34-depleted sulfur sources, i.e., coexisting pyrites produced by microbial sulfate reduction. According to a mixing model for paired sulfur isotopes of gypsum and pyrite, > 70% of gypsum sulfur is derived from pyrite reoxidation. The delta O-18(gypsum) values, ranging from 1.1 to 4.6 parts per thousand, suggest that the oxygen isotopes of porewater sulfate should fall between -2.4 and 1.1 parts per thousand, which are more depleted than seawater sulfate in O-18. Two mechanisms are proposed to explain the reoxidation of pyrite at different depths: in the lower section (10-4 m; Unit II), pyrite is oxidized by metal oxides under anaerobic conditions, producing O-18-depleted oxygen from seawater; while in the upper section (4-0 m; Unit I), pyrite reoxidation may occur under aerobic conditions, involving atmospheric oxygen. Either the aerobic or anaerobic mechanisms could cause drops in the porewater pH, leading to carbonate dissolution. These processes could therefore elevate the concentrations of sulfate and calcium ions in porewater, in which authigenic gypsum crystals are precipitated. In addition, both sulfur and oxygen isotopic signals of gypsum indicate a possible influence of methane on sulfate reduction in the mud sediments of core EC2005, which may be related to biogenic gas (dominated by CH4) in this region. Our new findings thus indicate that sulfide reoxidation in marine sediments plays an important role in the biogeochemical sulfur cycle on the continental margin. |
| 关键词 | Gypsum Pyrite Sulfur isotope Mud sediment East China Sea |
| DOI | 10.1016/j.marchem.2018.08.009 |
| 收录类别 | SCI |
| 语种 | 英语 |
| 资助项目 | National Natural Science Foundation of China[41430965]###577; National Natural Science Foundation of China[41606062]###578; Senior User Project of RV KEXUE[KEXUE2017G1]###970; State Key Laboratory of Marine Geology, Tongji University[MGK1824]###971; National Natural Science Foundation of China[41430965]; National Natural Science Foundation of China[41606062]; Senior User Project of RV KEXUE[KEXUE2017G1]; State Key Laboratory of Marine Geology, Tongji University[MGK1824] |
| WOS研究方向 | Chemistry ; Oceanography |
| WOS类目 | Chemistry, Multidisciplinary ; Oceanography |
| WOS记录号 | WOS:000447819800009 |
| 出版者 | ELSEVIER SCIENCE BV |
| 引用统计 | |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://ir.qdio.ac.cn/handle/337002/156601 |
| 专题 | 海洋地质与环境重点实验室 |
| 通讯作者 | Liu, Xiting; Li, Anchun |
| 作者单位 | 1.Ocean Univ China, Coll Marine Geosci, Key Lab Submarine Geosci & Prospecting Technol, Qingdao 266100, Peoples R China 2.Qingdao Natl Lab Marine Sci & Technol, Lab Marine Geol, Qingdao 266061, Peoples R China 3.Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 5.Univ Georgia, Dept Marine Sci, Athens, GA 30602 USA 6.China Univ Petr, Sch Geosci, Qingdao 266580, Peoples R China |
| 通讯作者单位 | 中国科学院海洋研究所 |
| 推荐引用方式 GB/T 7714 | Liu, Xiting,Li, Anchun,Dong, Jiang,et al. Nonevaporative origin for gypsum in mud sediments from the East China Sea shelf[J]. MARINE CHEMISTRY,2018,205:90-97. |
| APA | Liu, Xiting,Li, Anchun,Dong, Jiang,Zhuang, Guangchao,Xu, Fangjian,&Wan, Shiming.(2018).Nonevaporative origin for gypsum in mud sediments from the East China Sea shelf.MARINE CHEMISTRY,205,90-97. |
| MLA | Liu, Xiting,et al."Nonevaporative origin for gypsum in mud sediments from the East China Sea shelf".MARINE CHEMISTRY 205(2018):90-97. |
| 条目包含的文件 | ||||||
| 文件名称/大小 | 文献类型 | 版本类型 | 开放类型 | 使用许可 | ||
| Nonevaporative origi（2221KB） | 期刊论文 | 出版稿 | 限制开放 | CC BY-NC-SA | 浏览 | |
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
修改评论