Lake Qinghai sediment geochemistry linked to hydroclimate variability since the last glacial

doi:10.1016/j.quascirev.2015.05.015

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	Lake Qinghai sediment geochemistry linked to hydroclimate variability since the last glacial
	Jin, Zhangdong 1,2; An, Zhisheng 1,2; Yu, Jimin 3; Li, Fuchun 4; Zhang, Fei 1
	2015-08-15
发表期刊	QUATERNARY SCIENCE REVIEWS
卷号	122 页码:63-73
文章类型	Article
摘要	Geochemistry of basin sediments from semi-arid regions is valuable to understand past hydroclimatic changes. Here, we investigate the links of sedimentary geochemistry (Rb, Sr, Ca/Zr, TOC, and %CaCO3), carbonate mineralogy and ostracod shell delta O-18 of Lake Qinghai, a basin proximal to major dust production centers at mid-latitudes of the Northern Hemisphere, to changes in depositional conditions and hydroclimate during the past 32 ka. Surface lacustrine sediments are characterized by low-Rb, high-Sr, low-Rb/Sr, high-%CaCO3 and high-Ca/Zr values, in contrast to the chemical compositions of eolian loess (high-Rb, low-Sr, high-Rb/Sr, low-%CaCO3, and low-Ca/Zr). A direct comparison of soluble Ca and Sr in two short cores with instrumental water discharge data suggests that lacustrine precipitates in Lake Qinghai are dominated by authigenic aragonite formed under Ca2+-limited water conditions, and that the accumulation rate of aragonite dominantly depends on solute fluxes into the lake during the rainy seasons (late May to September). Our high-resolution down-core records show that sediments during the last glacial (similar to 32-19.8 ka) had high-Rb, low-Sr, low-%CaCO3, and low-Ca/Zr, indicating eolian dust (loess) accumulation in a desiccated basin under dry glacial conditions, further supported by grain size and pollen results. This type of sedimentation was maintained during the last deglacial (similar to 19.8-11.5 ka), but interrupted by episodic lacustrine precipitates with high-Sr, high-%CaCO3, high-Ca/Zr, and low-Rb. At similar to 11.5 ka, sedimentary Rb/Sr, Ca/Zr, %CaCO3 and TOC show dramatic and permanent changes, implying an abrupt shift in the atmospheric circulation at the onset of the Holocene in the Lake Qinghai region. Lacustrine precipitates have persisted throughout the Holocene with a maximum during the early to mid-Holocene (similar to 10.5-8.0 ka). Since similar to 8.0 ka, the gradual and significant decreases in aragonite and Sr accumulations in tandem with increasing dust deposit and more positive ostracod delta O-18 may be linked to a weakening of Asian summer monsoons during the mid-to-late Holocene. Overall, our records appear to show a high sensitivity of sediment development and geochemistry in Lake Qinghai to the regional hydroclimate changes since the last glacial. (C) 2015 Elsevier Ltd. All rights reserved.
关键词	Sediment Geochemistry Lacustrine Precipitate Hydroclimate ca2+-limited Lake Water Asian Dust Lake Qinghai
WOS标题词	Science & Technology ; Physical Sciences
DOI	10.1016/j.quascirev.2015.05.015
关键词[WOS]	NORTHEASTERN TIBETAN PLATEAU ; CHINESE LOESS PLATEAU ; ARID CENTRAL-ASIA ; ATMOSPHERIC DEPOSITION ; ENVIRONMENTAL-CHANGES ; HOLOCENE CLIMATE ; OXYGEN-ISOTOPE ; WESTERN PART ; BOSTEN LAKE ; MONSOON
收录类别	SCI
语种	英语
WOS研究方向	Physical Geography ; Geology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:000358097300004
引用统计	被引频次：77[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/361006/5075
专题	加速器质谱中心
作者单位	1.Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian 710075, Peoples R China 2.Xi An Jiao Tong Univ, Inst Global Environm Change, Xian 710049, Peoples R China 3.Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia 4.Nanjing Agr Univ, Coll Resources & Environm Sci, Nanjing 210095, Jiangsu, Peoples R China
推荐引用方式 GB/T 7714	Jin, Zhangdong,An, Zhisheng,Yu, Jimin,et al. Lake Qinghai sediment geochemistry linked to hydroclimate variability since the last glacial[J]. QUATERNARY SCIENCE REVIEWS,2015,122:63-73.
APA	Jin, Zhangdong,An, Zhisheng,Yu, Jimin,Li, Fuchun,&Zhang, Fei.(2015).Lake Qinghai sediment geochemistry linked to hydroclimate variability since the last glacial.QUATERNARY SCIENCE REVIEWS,122,63-73.
MLA	Jin, Zhangdong,et al."Lake Qinghai sediment geochemistry linked to hydroclimate variability since the last glacial".QUATERNARY SCIENCE REVIEWS 122(2015):63-73.