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DOI	10.1016/j.quaint.2009.12.013
	Evaporite minerals and geochemistry of the upper 400 m sediments in a core from the Western Qaidam Basin, Tibet
	Li, Minghui; Fang, Xiaomin; Yi, Chaolu; Gao, Shaopeng; Zhang, Weilin; Galy, Albert
通讯作者	Fang, XM (通讯作者)
发表日期	2010
ISSN	1040-6182
EISSN	1873-4553
起始页码	176
结束页码	189
卷号	218 期号:1-2
英文摘要	Qaidam Basin is a tectonically controlled depression on the northern margin of the Tibetan Plateau. In 2008, a long core was drilled in the Qahansilatu sub-basin in the western Qaidam basin. The sediment layers in the upper 400 m alternate between evaporite mineral layers and carbonaceous clay layers. The detailed mineralogical investigation focused on evaporite minerals including halite, gypsum, mirabilite, thenardite, glauberite, eugsterite, and bloedite. Gypsum and halite make up the majority of the evaporate minerals. Environmentally induced variations in the mineralogy and crystal habit of the sulfates have been extensively investigated. Gypsum has prismatic and pyramid habits, such as disc pyramid, stubby prismatic, slender prismatic. Visible isolated gypsum and aggregates (rosette/radial and twins) are mostly scattered in carbonaceous clay layers, suggesting that secondary gypsum is well developed. Gypsum may be a precursor mineral of glauberite, and thenardite is the precursor of bloedite. As a metastable and rare mineral, eugsterite does not appear in other Tibetan areas. It forms at the expense of pre-existing gypsum or thenardite in the core at an experimental temperature of higher than room temperature. The presence of eugsterite indicates a warm and/or hot climate at its deposition time. Mineralogical variations have been explained by the brine evolution of Na-Cl, Na-Ca-SO4, Na-SO4, Na-SO4-Cl, Na-Ca-SO4-Cl, Ca-SO4, and Na-Mg-SO4. For instance, Na-Mg-SO4 corresponds to bloedite, while Na-Ca-SO4-Cl to the assemblage of halite, gypsum and glauberite. The evaporite minerals and carbonaceous clay layers' alternation indicates the shift between dry and wet climate. According to the thickness, 18 evaporite stages and/or dry climate stages were identified from 0.97 Ma to about 0.03 Ma. The two early dry climate stages are identified at 0.96-0.97 Ma and 0.87 Ma. The other 16 evaporite stages occurred from 0.78 Ma to about 0.03 Ma. The evaporate-rich stages suggested that evaporation was high and groundwater inflow was sufficient at the sub-basin. (C) 2009 Elsevier Ltd and INQUA. All rights reserved.
关键词	NORTHERN TIBET QUATERNARY LACUSTRINE NORTHWESTERN CHINA TECTONIC UPLIFT CLIMATIC-CHANGE SALT-LAKE NW CHINA DEPOSITS GYPSUM EVOLUTION
语种	英语
WOS研究方向	Physical Geography ; Geology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:000278283100018
来源期刊	QUATERNARY INTERNATIONAL
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/257766
推荐引用方式 GB/T 7714	Li, Minghui,Fang, Xiaomin,Yi, Chaolu,et al. Evaporite minerals and geochemistry of the upper 400 m sediments in a core from the Western Qaidam Basin, Tibet[J]. 中国科学院青藏高原研究所,2010,218(1-2).
APA	Li, Minghui,Fang, Xiaomin,Yi, Chaolu,Gao, Shaopeng,Zhang, Weilin,&Galy, Albert.(2010).Evaporite minerals and geochemistry of the upper 400 m sediments in a core from the Western Qaidam Basin, Tibet.QUATERNARY INTERNATIONAL,218(1-2).
MLA	Li, Minghui,et al."Evaporite minerals and geochemistry of the upper 400 m sediments in a core from the Western Qaidam Basin, Tibet".QUATERNARY INTERNATIONAL 218.1-2(2010).