Greigite formed in early Pleistocene lacustrine sediments from the HeqingBasin, southwest China, and its paleoenvironmental implications

doi:10.1016/j.jseaes.2018.01.033

IEECAS OpenIR > 古环境研究室

	Greigite formed in early Pleistocene lacustrine sediments from the HeqingBasin, southwest China, and its paleoenvironmental implications
	Qiang, XK(Qiang, Xiaoke)1; Xu, XW(Xu, Xinwen)1,2; Zhao, H(Zhao, Hui)3; Fu, CF(Fu, Chaofeng)4; Qiang, Xiaoke
	2018-05
发表期刊	Journal of Asian Earth Sciences
卷号	156 期号:2018 页码:256-264
文章类型	期刊论文
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 (χ) 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 χ increase, Bc value increase and tends to be stable at about 50 mT. Therefore, we suggest that χ 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 χ 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.
关键词	Lacustrine Sediments Rock Magnetism Greigite Formation Sedimentary Environments
DOI	10.1016/j.jseaes.2018.01.033
收录类别	SCI
所属项目编号	41402151 ; 41572164 ; QYZDY-SSW-DQC001 ; ZDBS-SSW-DQC01ZDBSSSW-DQC01 ; SKLLQG1218 ; 2014KCT-27
语种	英语
项目资助者	National Science Fund of China ; National Science Fund of China ; Key Programs of Frontier Sciences, Chinese Academy ofSciences ; Key Programs of Frontier Sciences, Chinese Academy ofSciences ; Open Fund of the State Key Laboratory of Loess andQuaternary Geology ; Open Fund of the State Key Laboratory of Loess andQuaternary Geology ; Shaanxi ProvincialInnovation Team ; Shaanxi ProvincialInnovation Team
引用统计	被引频次：8[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.ieecas.cn/handle/361006/5279
专题	古环境研究室
通讯作者	Qiang, Xiaoke
作者单位	1.State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi′an 710061, China 2.Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Northwest University, Xi′an 710127, China 3.Department of Geography, Shaanxi Normal University, Xi’an 710062, China 4.Key Laboratory of Western Mineral Resources and Geological Engineering, Ministry of Education of China & Chang′an University, Xi′an 710054, China
第一作者单位	黄土与第四纪地质国家重点实验室（1985-2004）
推荐引用方式 GB/T 7714	Qiang, XK,Xu, XW,Zhao, H,et al. Greigite formed in early Pleistocene lacustrine sediments from the HeqingBasin, southwest China, and its paleoenvironmental implications[J]. Journal of Asian Earth Sciences,2018,156(2018):256-264.
APA	Qiang, XK,Xu, XW,Zhao, H,Fu, CF,&Qiang, Xiaoke.(2018).Greigite formed in early Pleistocene lacustrine sediments from the HeqingBasin, southwest China, and its paleoenvironmental implications.Journal of Asian Earth Sciences,156(2018),256-264.
MLA	Qiang, XK,et al."Greigite formed in early Pleistocene lacustrine sediments from the HeqingBasin, southwest China, and its paleoenvironmental implications".Journal of Asian Earth Sciences 156.2018(2018):256-264.

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