气候变化领域集成服务门户(CCPortal): Mineralogical and Geochemical Discrimination of the Occurrence and Genesis of Palygorskite in Eocene Sediments on the Northeastern Tibetan Plateau

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DOI	10.1002/2017GC007060
	Mineralogical and Geochemical Discrimination of the Occurrence and Genesis of Palygorskite in Eocene Sediments on the Northeastern Tibetan Plateau
	Ye, Chengcheng; Yang, Yibo; Fang, Xiaomin; Hong, Hanlie; Zhang, Weilin; Yang, Rongsheng; Song, Bowen; Zhang, Zhiguo
通讯作者	Fang, XM (通讯作者)
发表日期	2018
ISSN	1525-2027
起始页码	567
结束页码	581
卷号	19 期号:3
英文摘要	Palygorskite is a widely used indicator of semiarid to arid environments in paleoclimate studies. In this study, we present detailed mineralogical and geochemical investigations exploring the genesis of palygorskite found in Eocene fluvial sediment in the northern Qaidam Basin on the northeastern Tibetan Plateau. The presence of two types of palygorskite is revealed, based on their crystallinity characteristics and distinctive rare earth element (REE) patterns in the coexisting clay fraction. Well-crystallized palygorskite samples are characterized by remarkably negative Ce anomalies and obvious middle rare earth element enrichment. Poorly crystallized palygorskite samples generally exhibit positive Ce anomalies and less pronounced middle rare earth element enrichment, which resemble those of nonpalygorskite-bearing clay samples. Given the presence of an overall oxidized fluvial sedimentary environment, we attribute the well-crystallized palygorskite (which has textures comprising long, interwoven fibers) to direct precipitation (i.e., neoformation) occurring within a reducing environment during early/postdepositional processes while the poorly crystallized palygorskite (which is characterized by short, club-shaped single crystals) originates as catchment-delivered detritus. These poorly crystallized palygorskites occur mostly in 49.5-47.0 Ma and are accompanied by decreasing kaolinite content, increasing chlorite content, and abundant xerophytic spore-pollen from the Qaidam Basin, and its neighboring Xining Basin. Collectively, these evidences suggest that a less humid climate followed after the Early Eocene Climate Optimum.
关键词	EARTH-ELEMENT ENRICHMENTS WESTERN QAIDAM BASIN TECTONIC EVOLUTION CENOZOIC CLIMATE ASIAN MONSOON PEDOGENIC PALYGORSKITE PALEOGENE SEDIMENTS NORTHWEST CHINA CLAY-MINERALS UNITED-STATES
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000433289500001
来源期刊	GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
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/259234
推荐引用方式 GB/T 7714	Ye, Chengcheng,Yang, Yibo,Fang, Xiaomin,et al. Mineralogical and Geochemical Discrimination of the Occurrence and Genesis of Palygorskite in Eocene Sediments on the Northeastern Tibetan Plateau[J]. 中国科学院青藏高原研究所,2018,19(3).
APA	Ye, Chengcheng.,Yang, Yibo.,Fang, Xiaomin.,Hong, Hanlie.,Zhang, Weilin.,...&Zhang, Zhiguo.(2018).Mineralogical and Geochemical Discrimination of the Occurrence and Genesis of Palygorskite in Eocene Sediments on the Northeastern Tibetan Plateau.GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS,19(3).
MLA	Ye, Chengcheng,et al."Mineralogical and Geochemical Discrimination of the Occurrence and Genesis of Palygorskite in Eocene Sediments on the Northeastern Tibetan Plateau".GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS 19.3(2018).