干旱区生态环境知识资源中心(Arid): Fluvial sediments in the Alagxa Plateau as a dust source: iron mineralogical and geochemical evidence

Arid

	Fluvial sediments in the Alagxa Plateau as a dust source: iron mineralogical and geochemical evidence
	Wang Youjun; Jia Jia; Lu Hao; Lu Caichen; Xia Dunsheng
来源期刊	Journal of Arid Land
ISSN	1674-6767
出版年	2019
卷号	11 期号:2 页码:217-227
英文摘要	The Alagxa Plateau, in the margin of the northeastern Tibetan Plateau, is one of the most important dust source areas in East Asia, and the widespread sandy desert in the area is important both as a reservoir and a source of eolian silty. The northeastern margin of the Tibetan Plateau is one of the most actively-growing mountain belt on earth, and has large amounts of debris, with masses of fine grained material, which were continuously mobilized and deposited in the Alagxa Plateau by rivers, forming broad alluvial fans. It is possible that the role of fluvial sediments as a source of silty dust in the Alagxa Plateau has been underestimated. In this study, we test this hypothesis by investigating the iron mineralogical and geochemical characteristics of the fluvial sediments and the surface material of the sandy desert in the Alagxa Plateau, and comparing them with paleo-eolian dust deposits (loess) in the adjacent Chinese Loess Plateau (CLP) to investigate the possible linkages among the fluvial sediments, sandy desert and the last glacial loess of the CLP. The results show that sandy desert typically have high contents of goethite, and high ratios of goethite to hematite, similar to the fluvial sediments in the Alagxa Plateau. Based on the major element characteristics, field investigations and the results of previous studies, we found a genetic link between the silt component of the fluvial sediments and the sandy desert in the Alagxa Plateau with high value of Gt (goethite) and similarity of the Gt/(Hm (hematite)+Gt) ratio. But the silt component of the sandy desert main come from the adjacent fluvial sediments. The iron mineralogical characteristics (chi (magnetic susceptibility), chiARM (anhysteretic susceptibility), SIRM (saturation isothermal remanent magnetization) and SIRMAF100mT (SIRM demagnetized at 100 mT)) of the CLP samples overlap with those of the fluvial sediments in the Alagxa Plateau, but there is a mismatch with the sandy desert samples. This suggests that the fluvial sediments are the source of a large amount of silty material which could be transported to the CLP. Therefore, we conclude that the fluvial sediment in the Alagxa Plateau is an important source of eolian silt, which is deposited in downwind region, and that this source has been previously underestimated.
英文关键词	fluvial sediments silty dust sandy dust iron mineralogical and geochemical characteristic Alagxa Plateau
类型	Article
语种	英语
开放获取类型	Bronze
收录类别	CSCD
WOS研究方向	Geology
CSCD记录号	CSCD:6487036
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/336108
作者单位	Wang Youjun, College of Tourism and Environmental Resource, Zaozhuang University;;College of Geography and Environmental Sciences, Zhejiang Normal University, ;;, Zaozhuang;;, ;;Zhejiang 277100;;321004.; Jia Jia, College of Geography and Environmental Sciences, Zhejiang Normal University;;College of Earth and Environmental Sciences, Lanzhou University, ;;, ;;Lanzhou, Zhejiang;; 321004;;730000.; Lu Hao, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China.; Lu Caichen, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China.; Xia Dunsheng, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, Gansu 730000, China.
推荐引用方式 GB/T 7714	Wang Youjun,Jia Jia,Lu Hao,et al. Fluvial sediments in the Alagxa Plateau as a dust source: iron mineralogical and geochemical evidence[J],2019,11(2):217-227.
APA	Wang Youjun,Jia Jia,Lu Hao,Lu Caichen,&Xia Dunsheng.(2019).Fluvial sediments in the Alagxa Plateau as a dust source: iron mineralogical and geochemical evidence.Journal of Arid Land,11(2),217-227.
MLA	Wang Youjun,et al."Fluvial sediments in the Alagxa Plateau as a dust source: iron mineralogical and geochemical evidence".Journal of Arid Land 11.2(2019):217-227.