Methanogen-Mediated Precipitation of Mn Carbonates at the Expense of Mn Oxides
文献类型：期刊论文
| 作者 | Cai, Shixi2,3; Wei, Gangjian2,3; Xian, Haiyang1,2; Zhu, Jianxi1,2; Xu, Yi-Gang2,3 |
| 刊名 | GEOPHYSICAL RESEARCH LETTERS
 |
| 出版日期 | 2024-04-16 |
| 卷号 | 51期号:7页码:10 |
| 关键词 | methanogen microfossils Mn-carbonates extracellular polymeric substances mineral-microbe interaction dolomite problem great oxidation event |
| ISSN号 | 0094-8276 |
| DOI | 10.1029/2023GL106921 |
| 英文摘要 | Whether Mn carbonates can be used as a proxy for the oxygenation event is debated. Here we examined the Early Cretaceous lacustrine Mn carbonates from North China, which contain abundant microbial fossils. The extremely positive delta 13C (up to +15 parts per thousand relative to Vienna Peedee belemnite) and micro-area enrichment of Ni strongly indicate a methanogenic archaea origin of these microorganisms. Transmission electron microscope and electron energy loss spectroscopy show the nanoscale transformation of Mn-oxides (Mg-exchanged phyllomanganate) to Mn carbonates (kutnohorite), on extracellular polymeric substances. The reaction of the Mn oxides with organic matter resulted in increasing pH and alkalinity, together with the fluctuating pH, offering a suitable micro-environment for the transformation processes. These Mn carbonates are therefore indicative of an oxidized, sulfate-absent environment. The depicted scenario serves as a reference to ocean of the early Earth and provides a referable Mn oxide tracer for determining the emergence of the Great Oxidation Event. Microbial-mineral interactions have played an important role in the evolution of the Earth. Active methanogenesis exists in submerged sediments, and the biological activity of methanogen is directly or indirectly involved in the process of geochemical cycling and mineral precipitation. In modern ocean environments, the methanogenesis zone and the manganese reduction zone are respectively, located in the lower and upper layers of a chemical zone, so it is difficult for them to interact directly with each other. This study documents evidence for the direct reaction between them in the Early Cretaceous lacustrine sediment cores from north China. Precipitation of Mn carbonates was likely mediated by methanogenesis in couple with Mn oxide reduction. Such an environment resembles the oxygen oases in the ocean before the Great Oxidation Event and thus provides new insights into the marine environment at that time. Abundant methanogen microfossils in Mn carbonates with positive delta 13C Nanoscale transformation from Mn oxides to Mn carbonates pH fluctuations due to changes in redox conditions promote the formation of kutnohorite |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:001194851100001 |
| 源URL | [http://ir.gig.ac.cn/handle/344008/77208]  |
| 专题 | 同位素地球化学国家重点实验室 |
| 通讯作者 | Wei, Gangjian; Xu, Yi-Gang |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Geochem, CAS Key Lab Mineral & Metallogeny, Guangdong Prov Key Lab Mineral Phys & Mat, Guangzhou, Peoples R China 2.Univ Chinese Acad Sci, Coll Earth & Planetary Sci, Beijing, Peoples R China 3.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou, Peoples R China |
| 推荐引用方式 GB/T 7714 | Cai, Shixi,Wei, Gangjian,Xian, Haiyang,et al. Methanogen-Mediated Precipitation of Mn Carbonates at the Expense of Mn Oxides[J]. GEOPHYSICAL RESEARCH LETTERS,2024,51(7):10. |
| APA | Cai, Shixi,Wei, Gangjian,Xian, Haiyang,Zhu, Jianxi,&Xu, Yi-Gang.(2024).Methanogen-Mediated Precipitation of Mn Carbonates at the Expense of Mn Oxides.GEOPHYSICAL RESEARCH LETTERS,51(7),10. |
| MLA | Cai, Shixi,et al."Methanogen-Mediated Precipitation of Mn Carbonates at the Expense of Mn Oxides".GEOPHYSICAL RESEARCH LETTERS 51.7(2024):10. |
入库方式： OAI收割
来源：广州地球化学研究所
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