Tracing changes in monsoonal precipitation using Mg isotopes in Chinese loess deposits

doi:10.1016/j.gca.2019.05.036

IEECAS OpenIR > 古环境研究室

	Tracing changes in monsoonal precipitation using Mg isotopes in Chinese loess deposits
	Ma, Long 1,2,3; Sun, Youbin 3,4; Jin, Zhangdong 3,4; Bao, Zhian 1,2; Zhang, Pan 1,2; Meng, Zekun 1,2; Yuan, Honglin 1,2; Long, Xiaoping 1,2; He, Maoyong 3; Huang, Kang-Jun 1,2
通讯作者	Huang, Kang-Jun(hkj@nwu.edu.cn)
	2019-08-15
发表期刊	GEOCHIMICA ET COSMOCHIMICA ACTA
ISSN	0016-7037
卷号	259 页码:1-16
摘要	The widespread aeolian deposits on the Chinese Loess Plateau (CLP) have been investigated intensively as an outstanding archive of information on past variations of the East Asian Monsoon (EAM). However, differentiating the impacts of precipitation and temperature on loess-based proxies is difficult and complex, which hampers our ability to understand the variability and dynamics of the EAM. In this study, we investigated the Mg isotope composition (delta Mg-26) of the secondary carbonates in fine-grained loess samples from ten Holocene profiles and a loess-paleosol sequence, as well as in the primary carbonates of nine loess-source samples from the Asian inland deserts. Our aim was to explore the potential of the delta Mg-26 values of secondary carbonates in tracing precipitation changes. The results demonstrate that delta Mg-26 values are homogeneous (-2.07%60) in primary carbonates from different loess-sources, but display large variations in secondary carbonates of loess, increasing from -3.33%60 in the northwest CLP to -1.80%60 in the southeast CLP, and from -3.58%60 during the last glacial to -1.65%60 during the last interglacial. The variations were mainly controlled by EAM precipitation via the migration of isotopically light Mg, because Mg isotope fractionation during the formation of secondary carbonates is temperature insensitive, and the primary carbonate in different loess-sources has relatively constant delta Mg-26 values. This conclusion is further supported by high correlation (r(2) = 0.84) between modern mean annual precipitation (MAP) and delta Mg-26 in the secondary carbonates of spatial loess samples. Based on this delta Mg-26-MAP relationship, temporal variations in MAP were quantitatively estimated, ranging from 670 mm during the last interglacial to 270 mm during the last glacial at the southern CLP. Compared with previous estimates, our MAP exhibits a larger amplitude of glacial-interglacial fluctuations (similar to 400 mm) with a less uncertainty (53-76 mm), implying that delta Mg-26 values in secondary carbonates of loess can serve as a novel precipitation proxy to infer EAM variability and dynamics. (C) 2019 Elsevier Ltd. All rights reserved.
关键词	Chinese Loess Plateau Magnesium isotopes Secondary carbonates in loess Monsoonal precipitation reconstruction
DOI	10.1016/j.gca.2019.05.036
关键词[WOS]	LAST INTERGLACIAL PALEOSOL ; MAGNETIC-SUSCEPTIBILITY ; PEDOGENIC CARBONATE ; GLOBAL MONSOON ; EAST-ASIA ; MAGNESIUM ; FRACTIONATION ; DUST ; PLATEAU ; RECONSTRUCTION
收录类别	SCI ; SCI
语种	英语
资助项目	National Science Foundation of China[41807416] ; National Science Foundation of China[41602343] ; National Science Foundation of China[41890845] ; National Science Foundation of China[41621003] ; National Science Foundation of China[41525008] ; Open Funding of the State Key Laboratory of Loess and Quaternary Geology[SKLLQGZR1703] ; China Postdoctoral Science Foundation[2018M631183] ; 111 project[D17013] ; Strategic Priority Research Program of Chinese Academy of Sciences[XDB26000000]
WOS研究方向	Geochemistry & Geophysics
项目资助者	National Science Foundation of China ; Open Funding of the State Key Laboratory of Loess and Quaternary Geology ; China Postdoctoral Science Foundation ; 111 project ; Strategic Priority Research Program of Chinese Academy of Sciences
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000474198900001
出版者	PERGAMON-ELSEVIER SCIENCE LTD
引用统计	被引频次：16[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.ieecas.cn/handle/361006/13761
专题	古环境研究室
通讯作者	Huang, Kang-Jun
作者单位	1.Northwest Univ, Dept Geol, State Key Lab Continental Dynam, Xian 710069, Shaanxi, Peoples R China 2.Northwest Univ, Dept Geol, Shaanxi Key Lab Early Life & Environm, Xian 710069, Shaanxi, Peoples R China 3.Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian 710061, Shaanxi, Peoples R China 4.Chinese Acad Sci, Ctr Excellence Quaternary Sci & Global Change, Xian 710061, Shaanxi, Peoples R China
推荐引用方式 GB/T 7714	Ma, Long,Sun, Youbin,Jin, Zhangdong,et al. Tracing changes in monsoonal precipitation using Mg isotopes in Chinese loess deposits[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2019,259:1-16.
APA	Ma, Long.,Sun, Youbin.,Jin, Zhangdong.,Bao, Zhian.,Zhang, Pan.,...&Huang, Kang-Jun.(2019).Tracing changes in monsoonal precipitation using Mg isotopes in Chinese loess deposits.GEOCHIMICA ET COSMOCHIMICA ACTA,259,1-16.
MLA	Ma, Long,et al."Tracing changes in monsoonal precipitation using Mg isotopes in Chinese loess deposits".GEOCHIMICA ET COSMOCHIMICA ACTA 259(2019):1-16.