The rare earth elements of sequentially leached phases in the loess-paleosol sequence at Weinan on the southeastern Chinese Loess Plateau

doi:10.1016/j.quaint.2023.05.001

	The rare earth elements of sequentially leached phases in the loess-paleosol sequence at Weinan on the southeastern Chinese Loess Plateau
	Li, Tao 2,3,4; Liu, Yijie 2,3; Yang, Ruiyu 2,3; Chen, Tianyu 1,2; Li, Gaojun 2,3
刊名	QUATERNARY INTERNATIONAL
	2023-09-30
卷号	669 页码:43-52
关键词	Rare earth elements Chinese Loess Plateau Sequential leaching Eu anomaly Ce anomaly East Asian monsoon
ISSN号	1040-6182
DOI	10.1016/j.quaint.2023.05.001
通讯作者	Li, Gaojun(ligaojun@nju.edu.cn)
英文摘要	The rare earth elements (REEs) in loess sediments may preserve key information of paleoenvironmental changes in East Asia but remain poorly explored. Here we present the REE compositions of sequentially leached phases of loess sediments from a 16 m long loess-paleosol sequence collected from Weinan at the southern margin of the Chinese Loess Plateau (CLP). The REEs associated with carbonates, easily reducible oxides, reducible oxides, clay minerals, and the residual silicate minerals were sequentially leached with Na-acetate, hydroxylamine-HCl, Nadithionite/Na-citrate, 12 mol L-1 HCl and concentrated HF-HNO3 solutions. The results show that the REE concentrations of different phases vary in the loess-paleosol layers and are most enriched in the easily reducible phase (except for the residual phase), which is likely explained by the association of REEs with Mn-oxides. Significant Eu anomalies can only be found in the carbonate and easily reducible phases, with the carbonate phase being characterized by appreciable positive Eu anomalies and the easily reducible phase being characterized by negative Eu anomalies, indicating the incorporation of Eu2+ into secondary carbonates that leaves the authigenic Mn-oxides with depleted Eu relative to other REEs. The carbonate phase shows significant negative Ce anomalies, which is likely due to the preferential removal of Ce4+ by Mn oxides before the formation of secondary carbonates. Nevertheless, appreciable positive Ce anomalies for the easily reducible phase can only be found at the bottom of the paleosol S1 while significant negative Ce anomalies were found within the paleosol S1, indicating the downward leaching of Ce4+ that shows stronger complexation with the organic matters than REE3+ in the soil solution. This may partly account for the negative Ce anomalies previously found in the paleosols. Overall, our results suggest a two-stage evolution of Eu and Ce anomalies of the carbonate phase, with the first stage controlled by the formation of both Mn-oxides and secondary carbonates and the second stage dominated by the precipitation of secondary carbonates. The comparison of carbonate Eu and Ce anomalies with other paleoclimatic proxies indicates that the combination of Eu and Ce anomalies of the carbonate fraction of loess may be applied as novel proxy records of climate change in East Asia.
资助项目	National Natural Science Foundation of China[42002198] ; National Natural Science Foundation of China[41991325] ; National Natural Science Foundation of China[42061130212] ; Interdisciplinary Innovation Team of the Chinese Academy of Sciences[E0290101] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDB40010200] ; State Key Laboratory of Palaeobiology and Stratigraphy
WOS关键词	LAST INTERGLACIAL PALEOSOL ; CERIUM ANOMALIES ; MANGANESE OXIDE ; ZERO CHARGE ; GEOCHEMISTRY ; YTTRIUM ; BEHAVIOR ; IRON ; FRACTIONATION ; OXIDATION
WOS研究方向	Physical Geography ; Geology
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:001094651600001
资助机构	National Natural Science Foundation of China ; Interdisciplinary Innovation Team of the Chinese Academy of Sciences ; Strategic Priority Research Program of the Chinese Academy of Sciences ; State Key Laboratory of Palaeobiology and Stratigraphy
内容类型	期刊论文
源URL	[http://ir.nigpas.ac.cn/handle/332004/43236]
专题	中国科学院南京地质古生物研究所
通讯作者	Li, Gaojun
作者单位	1.Nanjing Univ, Sch Earth Sci & Engn, State Key Lab Mineral Deposit Res, Nanjing 210023, Jiangsu, Peoples R China 2.Nanjing Univ, Frontiers Sci Ctr Crit Earth Mat Cycling, Nanjing 210023, Jiangsu, Peoples R China 3.Nanjing Univ, Sch Earth Sci & Engn, MOE Key Lab Surficial Geochem, Nanjing 210023, Jiangsu, Peoples R China 4.Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, State Key Lab Palaeobiol & Stratig, Nanjing 210008, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Li, Tao,Liu, Yijie,Yang, Ruiyu,et al. The rare earth elements of sequentially leached phases in the loess-paleosol sequence at Weinan on the southeastern Chinese Loess Plateau[J]. QUATERNARY INTERNATIONAL,2023,669:43-52.
APA	Li, Tao,Liu, Yijie,Yang, Ruiyu,Chen, Tianyu,&Li, Gaojun.(2023).The rare earth elements of sequentially leached phases in the loess-paleosol sequence at Weinan on the southeastern Chinese Loess Plateau.QUATERNARY INTERNATIONAL,669,43-52.
MLA	Li, Tao,et al."The rare earth elements of sequentially leached phases in the loess-paleosol sequence at Weinan on the southeastern Chinese Loess Plateau".QUATERNARY INTERNATIONAL 669(2023):43-52.