气候变化领域集成服务门户(CCPortal): Variation of gypsum morphology along deep core SG-1, western Qaidam Basin (northeastern Tibetan Plateau) and its implication to depositional environments

CCPortal

DOI	10.1016/j.quaint.2015.12.102
	Variation of gypsum morphology along deep core SG-1, western Qaidam Basin (northeastern Tibetan Plateau) and its implication to depositional environments
	Li, Jiao; Li, Minghui; Fang, Xiaomin; Wang, Zhengrong; Zhang, Weilin; Yang, Yibo
通讯作者	Li, J ; Li, MH (通讯作者)
发表日期	2017
ISSN	1040-6182
EISSN	1873-4553
起始页码	71
结束页码	81
卷号	430
英文摘要	The Qaidam Basin is an arid, closed, intermontane basin located on the northern margins of the Tibetan Plateau in China. A 938.5 m-long core (SG-1), dated between similar to 2.8 Ma-0.1 Ma, was obtained from the western Qaidam Basin. Gypsum is one of major evaporative minerals in the core. A total of 201 gypsum samples were selected and their crystal morphologies were carefully investigated. The crystal habits are lenticular, prismatic, tabular, twinned, stubby, and aggregate. Prismatic crystals occur in the upper 723 m, while lenticular crystals exist almost entirely in the upper 523 m. Tabular crystals are the most common morphology. The total abundance of gypsum crystal (including tabular, lenticular, and prismatic forms) tends to increase with decreasing depth. The relationship between crystal habits and depositional environments is complex, because same morphology can appear in different environments, and different morphologies can also occur in the same depositional environment. However, the occurrence of different morphologies can be attributed to the variable growth rates caused by the inhibition effect of additional cations (e.g. Mg2+, Na+, K+ and Sr2+) on particular lattice parameters and the variation in precipitation experiments. The lattice parameters of the unit cell of gypsum, measured by X-ray diffraction method, are: a = 5.854-12.57 angstrom; b = 9.654-16.231 angstrom; and c = 5.163-14.024 angstrom; beta = 113.54-119.88 degrees; Volume = 601.55-712.65 angstrom(3). The substitution of K+, Na+ and Mg2+ for Ca2+ can reduce c-axis, while Sr2+ can reduce a and b axes. a/c, b/c, a/b tend to increase with K+, Na+ and Mg2+ and decrease with Sr2+. The Mg2+, Na+, K+ and Sr2+ contents in gypsum show significant variability, with K/Ca molar ratios varying from 1.03 x 10(-4) to 32.08 x 10(-4), Mg/Ca molar ratios from 0.0023 to 0.1629, Na/Ca molar ratios from 0.031 to 0.575, and Sr/Ca molar ratios from 5.59 x 10(-4) to 19.67 x 10(-4). Sr2+, Mg2+, Na+, and K+ concentrations in gypsum mainly depend on growth rate and brine concentration. (C) 2016 Elsevier Ltd and INQUA. All rights reserved.
关键词	CALCIUM-SULFATE DIHYDRATE QUATERNARY LACUSTRINE NEUTRON-DIFFRACTION EVAPORITE MINERALS M SEDIMENTS LONG CORE SALT LAKE DRY LAKE GROWTH SODIUM
英文关键词	Gypsum; Crystal morphology/habit; Co-precipitated ions; Lattice parameters; Depositional environment
语种	英语
WOS研究方向	Physical Geography ; Geology
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS记录号	WOS:000397933600009
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/259029
推荐引用方式 GB/T 7714	Li, Jiao,Li, Minghui,Fang, Xiaomin,et al. Variation of gypsum morphology along deep core SG-1, western Qaidam Basin (northeastern Tibetan Plateau) and its implication to depositional environments[J]. 中国科学院青藏高原研究所,2017,430.
APA	Li, Jiao,Li, Minghui,Fang, Xiaomin,Wang, Zhengrong,Zhang, Weilin,&Yang, Yibo.(2017).Variation of gypsum morphology along deep core SG-1, western Qaidam Basin (northeastern Tibetan Plateau) and its implication to depositional environments.QUATERNARY INTERNATIONAL,430.
MLA	Li, Jiao,et al."Variation of gypsum morphology along deep core SG-1, western Qaidam Basin (northeastern Tibetan Plateau) and its implication to depositional environments".QUATERNARY INTERNATIONAL 430(2017).