气候变化领域集成服务门户(CCPortal): Late Eocene clay boron-derived paleosalinity in the Qaidam Basin and its implications for regional tectonics and climate

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DOI	10.1016/j.sedgeo.2016.10.006
	Late Eocene clay boron-derived paleosalinity in the Qaidam Basin and its implications for regional tectonics and climate
	Ye, Chengcheng; Yang, Yibo; Fang, Xiaomin; Zhang, Weilin
通讯作者	Yang, YB (通讯作者)
发表日期	2016
ISSN	0037-0738
EISSN	1879-0968
起始页码	49
结束页码	59
卷号	346
英文摘要	The Qaidam Basin, located on the northeastern Tibetan Plateau and containing Cenozoic sediments with a maximum thickness of similar to 12,000 m, is an ideal place to study the phased uplift of the NE Tibetan Plateau and regional climate change. The estimation of the paleosalinity of sedimentary environments not only helps to evaluate the evolution of lakes in this region but offers insights into contemporaneous climate change. We present detailed geochemical and mineralogical investigations from the lacustrine interval of the Hongliugou section in the northern Qaidam Basin to reconstruct salinity fluctuations in the paleolake during the late Eocene era (similar to 42.0-35.5 Ma). The clay mineral assemblages mainly contain smectite, illite, chlorite, kaolinite and irregular illite/smectite mixed layers. Clay boron-derived paleosalinity estimates (equivalent boron content, Couch's paleosalimeter and B/Ga ratios) along with other proxies sensitive to salinity changes (e.g., Rb/K ratios and ostracod assemblages) collectively indicate an overall brackish sedimentary environment with a higher-salinity period at approximately 40.0 similar to 39.2 Ma. This higher-salinity period indicates a more arid environment and is probably related to global cooling. However, the global cooling in late Eocene cannot explain the overall stable long-term salinity pattern, implying that other factors exist. We propose that the migration of the Yiliping depression depocenter in the northern Qaidam and increased orographic rainfall induced by late Eocene tectonic activity at the northern margin of the basin might have partly offset the increase in salinity driven by global cooling. (C) 2016 Elsevier B.V. All rights reserved.
关键词	NE TIBETAN PLATEAU ALTYN-TAGH FAULT SEDIMENTARY RECORD MIDDLE EOCENE EVOLUTION UPLIFT MARINE GROWTH MAGNETOSTRATIGRAPHY QINGHAI
英文关键词	Late Eocene; Qaidam Basin; Paleosalinity; Boron; Clay minerals; Global cooling
语种	英语
WOS研究方向	Geology
WOS类目	Geology
WOS记录号	WOS:000390738300005
来源期刊	SEDIMENTARY GEOLOGY
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/258685
推荐引用方式 GB/T 7714	Ye, Chengcheng,Yang, Yibo,Fang, Xiaomin,et al. Late Eocene clay boron-derived paleosalinity in the Qaidam Basin and its implications for regional tectonics and climate[J]. 中国科学院青藏高原研究所,2016,346.
APA	Ye, Chengcheng,Yang, Yibo,Fang, Xiaomin,&Zhang, Weilin.(2016).Late Eocene clay boron-derived paleosalinity in the Qaidam Basin and its implications for regional tectonics and climate.SEDIMENTARY GEOLOGY,346.
MLA	Ye, Chengcheng,et al."Late Eocene clay boron-derived paleosalinity in the Qaidam Basin and its implications for regional tectonics and climate".SEDIMENTARY GEOLOGY 346(2016).