Origin of the Neoproterozoic Fulu iron formation, South China: Insights from iron isotopes and rare earth element patterns
文献类型：期刊论文
| 作者 | Busigny, Vincent1,2; Planaysky, Noah J.3; Goldbaum, Elizabeth4,7; Lechte, Maxwell A.5; Feng, Lianjun6; Lyons, Timothy W.4 |
| 刊名 | GEOCHIMICA ET COSMOCHIMICA ACTA
 |
| 出版日期 | 2018-12-01 |
| 卷号 | 242页码:123-142 |
| 关键词 | Iron isotopes REE Proterozoic Cryogenian Iron formation |
| ISSN号 | 0016-7037 |
| DOI | 10.1016/j.gca.2018.09.006 |
| 英文摘要 | In the Neoproterozoic Era there was widespread deposition of iron formations in close association with global or near glaciations. These 'Snowball Earth' glaciations likely played a key role in iron formation distribution and deposition. However, the environmental conditions, Fe sources, and formation mechanisms remain debated. Here we present the rare earth element geochemistry and Fe isotope composition of the synglacial iron formation within the Neoproterozoic Fulu Formation, South China. The Fulu iron formation consists of layers of authigenic minerals (mainly hematite) and detrital components (quartz, feldspars, Fe chlorite, and minor biotite). Positive Eu anomalies in one of the Fulu localities indicate a hydrothermal influence, suggesting that Fe was mainly sourced from distal hydrothermal systems. The bulk-rock Fe isotope composition of the Fulu iron formation shows a large range, with delta Fe-56 from -0.23 to +1.78 parts per thousand. Correlation between bulk-rock delta Fe-56 values and Al/Fe ratios demonstrates that delta Fe-56 variability reflects, in part, varying proportions of authigenic versus detrital components. The Fe isotope composition of authigenic hematite is calculated by a linear regression and shows delta Fe-56 between +0.83 and +2.21 parts per thousand, with an average at +1.54 +/- 0.50 parts per thousand (2 sigma, n = 41). Using a dispersion-reaction model, the high delta Fe-56 values of hematite constrain local dissolved O-2 concentrations of the ocean to less than 0.4 nmol/L, even in the shallow part of the water column. This relationship is consistent with highly reducing conditions in the Neoproterozoic oceans favored by isolation from the atmosphere by a sea ice. We attribute the extremely positive values to partial iron oxidation in waters that were cold relative to modern surface oceans. The dominant occurrence of hematite supports an abiotic precipitation pathway, given that biological activity would have introduced organic matter to the sediments and led to partial reduction of Fe(III) oxides and subsequent formation of magnetite and/or siderite, as is observed in Archean and Paleoproterozoic iron formations. Oxic glacial meltwater and/or O-2 vertical transfer from the atmosphere to the upper ocean linked to ice dynamics is likely to have mediated the abiotic oxidation. We propose that vertical transfer of O-2 resulted from the deposition of snow that trapped air bubbles at the top of the glacier coupled to a melting of the bottom of the glacier, which in combination delivered a limited but continuous amount of O-2 to the ocean. (C) 2018 Elsevier Ltd. All rights reserved. |
| WOS关键词 | MID-ATLANTIC RIDGE ; BARBERTON GREENSTONE-BELT ; TRUE POLAR WANDER ; BILLION YEARS AGO ; FE-ISOTOPE ; SNOWBALL EARTH ; FE(II) OXIDATION ; FERRUGINOUS CONDITIONS ; TRANSVAAL SUPERGROUP ; HYDROTHERMAL FLUIDS |
| 资助项目 | National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; UnivEarths Labex program at Sorbonne Paris Cite[ANR-10-LABX-0023] ; UnivEarths Labex program at Sorbonne Paris Cite[ANR-11-IDEX-0005-02] ; Packard Foundation ; NSFC[41072145] ; Earth-Life Transitions Program of NSF-EAR ; NASA Astrobiology Institute[NNA15BB03A] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000446475700008 |
| 出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
| 资助机构 | National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; UnivEarths Labex program at Sorbonne Paris Cite ; UnivEarths Labex program at Sorbonne Paris Cite ; Packard Foundation ; Packard Foundation ; NSFC ; NSFC ; Earth-Life Transitions Program of NSF-EAR ; Earth-Life Transitions Program of NSF-EAR ; NASA Astrobiology Institute ; NASA Astrobiology Institute ; National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; UnivEarths Labex program at Sorbonne Paris Cite ; UnivEarths Labex program at Sorbonne Paris Cite ; Packard Foundation ; Packard Foundation ; NSFC ; NSFC ; Earth-Life Transitions Program of NSF-EAR ; Earth-Life Transitions Program of NSF-EAR ; NASA Astrobiology Institute ; NASA Astrobiology Institute ; National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; UnivEarths Labex program at Sorbonne Paris Cite ; UnivEarths Labex program at Sorbonne Paris Cite ; Packard Foundation ; Packard Foundation ; NSFC ; NSFC ; Earth-Life Transitions Program of NSF-EAR ; Earth-Life Transitions Program of NSF-EAR ; NASA Astrobiology Institute ; NASA Astrobiology Institute ; National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; National Program of Planetology (PNP) 2015 of the Institut National des Sciences de l'Univers ; UnivEarths Labex program at Sorbonne Paris Cite ; UnivEarths Labex program at Sorbonne Paris Cite ; Packard Foundation ; Packard Foundation ; NSFC ; NSFC ; Earth-Life Transitions Program of NSF-EAR ; Earth-Life Transitions Program of NSF-EAR ; NASA Astrobiology Institute ; NASA Astrobiology Institute |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/89204]  |
| 专题 | 地质与地球物理研究所_科技支撑系统 |
| 通讯作者 | Busigny, Vincent |
| 作者单位 | 1.Univ Paris Diderot, Sorbonne Paris Cite, Inst Phys Globe Paris, Paris, France 2.Inst Univ France, Paris, France 3.Yale Univ, Dept Geol & Geophys, New Haven, CT USA 4.Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA 5.Univ Melbourne, Sch Earth Sci, Parkville, Vic 3010, Australia 6.Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China 7.US Geol Survey, 959 Natl Ctr, Reston, VA 22092 USA |
| 推荐引用方式 GB/T 7714 | Busigny, Vincent,Planaysky, Noah J.,Goldbaum, Elizabeth,et al. Origin of the Neoproterozoic Fulu iron formation, South China: Insights from iron isotopes and rare earth element patterns[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2018,242:123-142. |
| APA | Busigny, Vincent,Planaysky, Noah J.,Goldbaum, Elizabeth,Lechte, Maxwell A.,Feng, Lianjun,&Lyons, Timothy W..(2018).Origin of the Neoproterozoic Fulu iron formation, South China: Insights from iron isotopes and rare earth element patterns.GEOCHIMICA ET COSMOCHIMICA ACTA,242,123-142. |
| MLA | Busigny, Vincent,et al."Origin of the Neoproterozoic Fulu iron formation, South China: Insights from iron isotopes and rare earth element patterns".GEOCHIMICA ET COSMOCHIMICA ACTA 242(2018):123-142. |
入库方式： OAI收割
来源：地质与地球物理研究所
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