中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Greigite formed in early Pleistocene lacustrine sediments from the Heqing Basin, southwest China, and its paleoenvironmental implications

文献类型:期刊论文

作者Fu, Chaofeng4; Zhao, Hui1; Xu, Xinwen2,3; Qiang, Xiaoke2
刊名JOURNAL OF ASIAN EARTH SCIENCES
出版日期2018-05-01
卷号156期号:1页码:256-264
关键词Lacustrine Sediments Rock Magnetism Greigite Formation Sedimentary Environments
DOI10.1016/j.jseaes.2018.01.033
文献子类Article
英文摘要The ferrimagnetic iron sulfide greigite (Fe3S4) occurs widely in sulfidic lacustrine and marine sedimentary environments. Knowledge of its formation and persistence is important for both magnetostratigraphic and paleoenvironmental studies. Although the formation mechanism of greigite has been widely demonstrated, the sedimentary environments associated with greigite formation in lakes, especially on relatively long timescales, are poorly understood. A long and continuous sequence of Pleistocene lacustrine sediments was recovered in the Heqing drill core from southwestern China, which provides an outstanding record of continental climate and environment. Integrated magnetic, geochemical, and paleoclimatic analysis of the lacustrine sequence provides an opportunity to improve our understanding of the environmental controls on greigite formation. Rock magnetic and scanning electron microscope analyses of selected samples from the core reveal that greigite is present in the lower part of the core (part 1, 665.8-372.5 m). Greigite occurs throughout this interval and is the dominant magnetic mineral, irrespective of the climatic state. The magnetic susceptibility (chi) record, which is mainly controlled by the concentration of greigite, matches well with variations in the Indian Summer Monsoon (ISM) index and total organic carbon (TOC) content, with no significant time lag. This indicates that the greigite formed during early diagenesis. In greigite-bearing intervals, with the chi increase, B-c value increase and tends to be stable at about 50 mT. Therefore, we suggest that chi values could estimate the variation of greigite concentration approximately in the Heqing core. Greigite favored more abundant in terrigenous-rich and organic poor layers associated with weak summer monsoon which are characterized by high chi values, high Fe content, high Rb/Sr ratio and low TOC content. Greigite enhancement can be explained by variations in terrigenous inputs. Our studies demonstrate that, not only the greigite formation, but also its concentration changes could be useful for studying climatic and environmental variability in sulfidic environments.
WOS关键词MAGNETIC PARTICLE-SYSTEMS ; REVERSAL CURVE DIAGRAMS ; BEARING SEDIMENTS ; ROCK MAGNETISM ; IRON SULFIDES ; LAKE ; SEA ; RECORD ; FE3S4 ; SUSCEPTIBILITY
WOS研究方向Geology
WOS记录号WOS:000428829700020
源URL[http://ir.ieecas.cn/handle/361006/5211]  
专题地球环境研究所_古环境研究室
作者单位1.Shaanxi Normal Univ, Dept Geog, Xian 710062, Shaanxi, Peoples R China
2.Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian 710061, Shaanxi, Peoples R China
3.Northwest Univ, Shaanxi Key Lab Earth Surface Syst & Environm Car, Xian 710127, Shaanxi, Peoples R China
4.Changan Univ, Minist Educ China, Key Lab Western Mineral Resources & Geol Engn, Xian 710054, Shaanxi, Peoples R China
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Fu, Chaofeng,Zhao, Hui,Xu, Xinwen,et al. Greigite formed in early Pleistocene lacustrine sediments from the Heqing Basin, southwest China, and its paleoenvironmental implications[J]. JOURNAL OF ASIAN EARTH SCIENCES,2018,156(1):256-264.
APA Fu, Chaofeng,Zhao, Hui,Xu, Xinwen,&Qiang, Xiaoke.(2018).Greigite formed in early Pleistocene lacustrine sediments from the Heqing Basin, southwest China, and its paleoenvironmental implications.JOURNAL OF ASIAN EARTH SCIENCES,156(1),256-264.
MLA Fu, Chaofeng,et al."Greigite formed in early Pleistocene lacustrine sediments from the Heqing Basin, southwest China, and its paleoenvironmental implications".JOURNAL OF ASIAN EARTH SCIENCES 156.1(2018):256-264.

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来源:地球环境研究所

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