干旱区生态环境知识资源中心(Arid): Grain-size-dependent geochemical characteristics of Middle and Upper Pleistocene loess sequences from the Junggar Basin: Implications for the provenance of Chinese eolian deposits

Arid

DOI	10.1016/j.palaeo.2019.109458
	Grain-size-dependent geochemical characteristics of Middle and Upper Pleistocene loess sequences from the Junggar Basin: Implications for the provenance of Chinese eolian deposits
	Li, Xiaojing 1,2,3; Zan, Jinbo 1,2,3; Yang, Rongsheng 1,2,3; Fang, Xiaomin 1,2,3; Yang, Shengli 4,5
通讯作者	Zan, Jinbo
来源期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
ISSN	0031-0182
EISSN	1872-616X
出版年	2020
卷号	538
英文摘要	Thick loess-paleosol sequences are widely distributed in the arid inland basins of northwestern China. The geochemical composition of these sediments provides important constraints on the provenance of Chinese eolian deposits. However, grain-size-dependent geochemical characteristics of Early-Middle Pleistocene loess deposits from these arid inland basins have not been investigated. The paucity of such studies hinders a full understanding of provenance changes of loess deposits from the Chinese Loess Plateau (CLP). In the present study, we performed a detailed major, trace and rare earth element analysis of multiple grain-size fractions of Middle Pleistocene loess deposits from the Dongwan section (DW) in the Junggar Basin. We found that the major, trace and rare earth element concentrations of the DW loess are grain-size-dependent, with higher concentrations in the fine fraction. In addition, the < 5 mu m and 5-20 mu m fractions are more homogeneous in composition than the coarse fractions, indicating that they were extremely well mixed prior to deposition. Compared to contemporaneous loess deposits from the CLP and surface loess samples from Tajikistan and Ili Basin in Xinjiang, the loess deposits of the DW section have higher major element ratios of TiO2/Al2O3 and K2O/Al2O3, and REE ratios of La-N/Yb-N, Gd-N/Yb-N and La-N/Sm-N, indicating that the loess deposits in the Junggar Basin have distinctive local or regional geochemical characteristics. These results support the view that the Junggar Basin is not a potential source region of the loess in the CLP, at least since the Middle Pleistocene. Furthermore, temporal variations in the major element and REE ratios of the coarse fractions (20-75 mu m and > 75 mu m) from the DW section changed significantly at similar to 0.5 Ma, which may have arisen from intensified physical erosion or increased wind speeds in the northern Tianshan area.
英文关键词	Major elements Trace elements Rare earth elements Chinese Loess Plateau Tianshan Central Asia
类型	Article
语种	英语
国家	Peoples R China
收录类别	SCI-E
WOS记录号	WOS:000508751800040
WOS关键词	TIBETAN PLATEAU ; MAGNETIC-PROPERTIES ; PALEOSOL SAMPLES ; ILI BASIN ; DESERT ; EVOLUTION ; SEDIMENTS ; UPLIFT ; FRACTIONS ; RECORDS
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS研究方向	Physical Geography ; Geology ; Paleontology
来源机构	兰州大学 ; 中国科学院青藏高原研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/315272
作者单位	1.Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China; 2.Chinese Acad Sci, Key Lab Continental Collis & Plateau Uplift, Inst Tibetan Plateau Res, Beijing 100101, Peoples R China; 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China; 4.Lanzhou Univ, Coll Earth Environm Sci, Lanzhou 730000, Peoples R China; 5.Lanzhou Univ, Key Lab Western Chinas Environm Syst MOE, Lanzhou 730000, Peoples R China
推荐引用方式 GB/T 7714	Li, Xiaojing,Zan, Jinbo,Yang, Rongsheng,et al. Grain-size-dependent geochemical characteristics of Middle and Upper Pleistocene loess sequences from the Junggar Basin: Implications for the provenance of Chinese eolian deposits[J]. 兰州大学, 中国科学院青藏高原研究所,2020,538.
APA	Li, Xiaojing,Zan, Jinbo,Yang, Rongsheng,Fang, Xiaomin,&Yang, Shengli.(2020).Grain-size-dependent geochemical characteristics of Middle and Upper Pleistocene loess sequences from the Junggar Basin: Implications for the provenance of Chinese eolian deposits.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,538.
MLA	Li, Xiaojing,et al."Grain-size-dependent geochemical characteristics of Middle and Upper Pleistocene loess sequences from the Junggar Basin: Implications for the provenance of Chinese eolian deposits".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 538(2020).