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DOI	10.1016/j.epsl.2017.02.009
	Eolian dust forcing of river chemistry on the northeastern Tibetan Plateau since 8 Ma
	Yang, Yibo; Galy, Albert; Fang, Xiaomin; Yang, Rongsheng; Zhang, Weilin; Zan, Jinbo
通讯作者	Yang, YB ; Fang, XM (通讯作者)
发表日期	2017
ISSN	0012-821X
EISSN	1385-013X
起始页码	200
结束页码	210
卷号	464
英文摘要	Eolian dust is one of the most important factors controlling fluvial hydrological evolution in modern arid and semi-arid central Asia. Here, we present the bulk carbonate Ca-Mg-Sr concentrations and Sr isotopic compositions recorded in water soluble salts, carbonate and silicate fractions, as well as the Nd isotopic compositions in the silicate fraction of a Late Miocene (12.2-5.1Ma) fluvial sequence exhibiting paleosol development, in the Linxia Basin on the northeastern Tibetan Plateau (TP). Bulk carbonate Mg-Sr systematics show a distinct pattern in log-log plots of Mg/Ca versuslog Sr/Ca ratios, and clearly higher 87Sr/86Sr ratios since similar to 8Ma. These findings cannot be adequately explained by the mechanism of prior calcite precipitation (PCP)-this latter process results in a positive correlation between the Mg/Ca and Sr/Ca ratios in authigenic calcite, evident in the fixed gradient in their log-log plots and has been isolated as being the major factor controlling carbonate Mg-Sr systematics before 8 Ma. Nor can these findings be explained by other mechanisms related to the catchment's provenance/sedimentation. The dramatic changes in carbonate Sr contents, Sr isotopes, and Sr/Mg ratios since similar to 8Ma may therefore be inferred to have been triggered by significant inputs of eolian dust viathe dissolution of dust carbonates and evaporites in the paleowaters where fluvial and paleosol carbonates precipitated. This process of eolian dust input can be reliably illustrated using a binary mixing model corresponding to a series of varying PCP fluxes (identical to processes affecting the area before 8Ma) combined with a constant eolian influx calculated from the co-variations between Mg/Ca, Sr/Ca and Sr isotopic ratios. Eolian dust also leaves a fingerprint in the carbonate and silicate minerals of bulk sediments, as revealed respectively by their Sr and Nd isotopic compositions. Eolian dust compositions for the similar to 8-5Ma on the northeastern TP can thus be taken to be characterized by a epsilon Nd value <=-10.5for the silicate fraction, and by a 87Sr/86Sr value >= 0.7115 for the labile faction (carbonates and evaporites). Eolian dust is now recognized to have made a significant impact on the hydrological evolution of arid and semi-arid northern China as far back as similar to 8Ma, suggesting an enhanced regime of dust activity and regional aridification in central Asia at that time. (C) 2017 Elsevier B.V. All rights reserved.
关键词	CHINESE LOESS PLATEAU LINXIA BASIN HIMALAYAN RIVERS NORTHERN CHINA CARBONATE PROVENANCE SILICATE DEPOSITS UPLIFT ND
英文关键词	eolian dust; strontium isotopes; prior calcite precipitation; palaeohydrology; Tibetan Plateau
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000395923500019
来源期刊	EARTH AND PLANETARY SCIENCE LETTERS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259003
推荐引用方式 GB/T 7714	Yang, Yibo,Galy, Albert,Fang, Xiaomin,et al. Eolian dust forcing of river chemistry on the northeastern Tibetan Plateau since 8 Ma[J]. 中国科学院青藏高原研究所,2017,464.
APA	Yang, Yibo,Galy, Albert,Fang, Xiaomin,Yang, Rongsheng,Zhang, Weilin,&Zan, Jinbo.(2017).Eolian dust forcing of river chemistry on the northeastern Tibetan Plateau since 8 Ma.EARTH AND PLANETARY SCIENCE LETTERS,464.
MLA	Yang, Yibo,et al."Eolian dust forcing of river chemistry on the northeastern Tibetan Plateau since 8 Ma".EARTH AND PLANETARY SCIENCE LETTERS 464(2017).