陈丹婷^1,2,,
彭渤^1,2,,,
方小红^1,3,
邬思成^1,2,
刘静^1,2,
赵亚方^1,2,
戴亚南^1,2
1. 湖南师范大学地理科学学院, 湖南 长沙 410081
2. 湖南师范大学环境重金属污染机理与生态修复实验室, 湖南 长沙 410081
3. 衡阳师范学院城市与旅游学院, 湖南 衡阳 421000

基金项目: 湖南省地理学一流学科(地理学-5010002)建设项目、湖南省高校科技创新团队支持计划项目(2014)和国家自然科学基金项目(批准号: 41073095)共同资助


详细信息

作者简介: 陈丹婷, 女, 25岁, 硕士研究生, 自然地理学专业, E-mail: cdt3012@163.com

通讯作者: 彭渤, E-mail: pengbo@hunnu.edu.cn

中图分类号: P595;P941.78

收稿日期:2021-01-31
修回日期:2021-04-29
刊出日期:2021-09-30

Geochemistry of major elements in bed sediments from inlets of the Four Rivers to Dongting Lake, China

CHEN Danting^1,2,,
PENG Bo^1,2,,,
FANG Xiaohong^1,3,
WU Sicheng^1,2,
LIU Jing^1,2,
ZHAO Yafang^1,2,
DAI Yanan^1,2
1. College of Geographic Science, Hunan Normal University, Changsha 410081, Hunan
2. Key Laboratory of Environmental Heavy-Metal Contamination and Ecological Remediation, Hunan Normal University, Changsha 410081, Hunan
3. College of City and Tourism, Hengyang Normal University, Hengyang 421000, Hunan


More Information

Corresponding author: PENG Bo,E-mail:pengbo@hunnu.edu.cn

MSC: P595;P941.78

--> Received Date: 31 January 2021
Revised Date: 29 April 2021
Publish Date: 30 September 2021


摘要
摘要:本研究利用X射线荧光分析仪（XRF）对洞庭湖"四水"（湘江、资江、沅江、澧水）入湖河床沉积物进行主量元素地球化学分析，探讨"四水"入湖沉积物主量元素组成特征及其影响因素。结果表明，洞庭湖"四水"入湖沉积物中SiO₂、Al₂O₃、Fe₂O₃、K₂O、P₂O₅、LOI等元素含量变化相对较小、分布特征相似；而MnO、MgO、CaO、Na₂O等则含量变化较大，在各河流沉积物中分布差异明显。其中沅江和澧水入湖沉积物中MgO、CaO、Na₂O等的含量明显高于湘江和资江沉积物，而MnO则反之；澧水沉积物TiO₂含量明显偏高。且湘江、资江、澧水沉积物中TiO₂、Al₂O₃、Fe₂O₃、MnO、MgO、CaO、P₂O₅、LOI等主量元素含量变化有明显的粒度效应，而沅江沉积物则不然。不同河流入湖沉积物主量元素组成差异明显，沉积物主量元素组成的明显差异与流域源岩岩性、化学风化作用、水动力条件等因素有关。其中湘江和资江沉积物主量元素组成主要与由上地壳+花岗岩组成的源岩有关；沅江沉积物元素组成受湖南板岩的影响明显；而澧水沉积物元素组成则是总体与上地壳元素组成相近似的区域源岩有关，并受长江沉积物影响。湘江和资江沉积物显示的风化程度明显高于沅江和澧水沉积物。但化学风化作用是通过不同抗风化能力岩石的空间分布而影响沉积物的元素组成。此外，湘江、资江、澧水沉积物元素组成受水动力条件影响，而沅江沉积物则不然。但水动力分选对沉积物元素组成的影响也受源岩岩性的控制。因此，流域源岩岩性是控制"四水"入湖沉积物主量元素组成的主要影响因素。
关键词: 主量元素/
源岩/
化学风化作用/
粒度/
沉积物/
洞庭湖

Abstract:The concentrations of major elements in bed sediments from inlets of the Four Rivers (Xiangjiang, Zijiang, Yuanjiang, and Lishui rivers) to Dongting Lake were measured using the X-ray fluorescence(XRF) technique, with purposes to characterizing the chemical compositions of the sediments and to understanding the possible factors that impact directly on the chemical composition of the sediments. The results show that the concentrations of major elements SiO₂, Al₂O₃, Fe₂O₃, K₂O, P₂O₅ and LOI are less variable, and they show similar distribution patterns in sediments of the Four River inlets. While, those of MnO, MgO, CaO and Na₂O are significantly variable, and these elements display different distribution features in sediments of the Four River inlets. Meanwhile, the contents of MgO, CaO and Na₂O in sediments of Yuanjiang and Lishui rivers are significantly higher than that of Xiangjiang and Zijiang rivers, while those of MnO vary oppositely. Moreover, sediments of the Lishui River has higher contents of TiO₂ than the sediments of other three rivers do. In addition, the contents of TiO₂, Al₂O₃, Fe₂O₃, MnO, MgO, CaO, P₂O₅ and LOI in sediments of Xiangjiang, Zijiang, and Lishui rivers have obvious grain size effect, but not in sediments of Yuanjiang River. Thus, the major element compositions are different from the sediments of each river, and this difference was caused by lithological properties of the source rocks in the Four Rivers watersheds, and influenced by chemical weathering of the source rocks and the hydrological factors of different rivers. The major element compositions of the sediments from Xiangjiang and Zijiang rivers were determined mainly by source rocks that have comparable element compositions of the upper continental crust and the granitic rocks; those of Yuanjiang River were significantly impacted by the slate distributed in the watershed; and those of Lishui River were influenced by source rocks that have comparable compositions of the upper continental crust, and also possibly by the sediments from Yangtze River. The degree of chemical weathering indicated by sediments of Xiangjiang and Zijiang rivers are distinctly higher than those by the sediments of Yuanjiang and Lishui rivers. However, the impact of chemical weathering on major element composition of the sediments was significantly relative to the distribution of the source rocks that resisted differently to the chemical weathering. Also, the element compositions of sediments from Xiangjiang, Zijiang, and Lishui rivers were impacted significantly by the hydrological dynamics, while those of Yuanjiang River were not. Thus, the impact of hydrological dynamics of the water systems on major element compositions was also relative to the distribution of source rocks that have different lithological properties. Therefore, it is concluded that the lithological composition of source rocks is the major factor that controlled and determined the element compositions of the sediments from the Four River inlets.
Key words:major element/
source rock/
chemical weathering/
grain size/
sediment/
Dongting Lake



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