气候变化领域集成服务门户(CCPortal): Early Eocene High-flux Magmatism and Concurrent High-temperature Metamorphism in the Gangdese Belt, Southern Tibet

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DOI	10.1130/B35770.1
	Early Eocene High-flux Magmatism and Concurrent High-temperature Metamorphism in the Gangdese Belt, Southern Tibet
	Ma X.; Xu Z.; Meert J.G.; Tian Z.; Li H.
发表日期	2021
ISSN	167606
起始页码	1194
结束页码	1216
卷号	133
英文摘要	The Himalayan-Tibetan orogen represents one of the major Cenozoic tectonic features on Earth, and yet considerable debate continues over the timing and sequence of collisional events leading to its formation. In this contribution, we present new field relations, petrology, geochemistry, geochronology, and phase equilibria modeling in the Gangdese belt of southern Tibet in an effort to address Indo-Asian collisional events in the region. These investigations reveal that the dominantly dioritic Nymo intrusive complex was formed at ca. 50–47 Ma. We establish that the Jurassic-aged Bima volcano-sedimentary sequence underwent early Eocene (50–47 Ma) high-temperature (HT) amphibolite-facies metamorphism. Petrology and phase equilibria modeling of garnet-biotite schists in the Bima rocks reveals mineral assemblages of melt + plagioclase + garnet + biotite + magnetite + ilmenite + sillimanite formed under conditions of 5.3–7.5 kbar and 700–800 °C. We contend that the early Eocene Nymo intrusive complex represents part of the ca. 50 Ma high-flux magmatic “flare-up” that triggered the HT amphibolite-facies metamorphism within the overlying plate during Indo-Asian collision. The synchroneity of high-flux magmatism and HT metamorphism in the Gangdese belt roughly coincided with the continuing Indo-Asian collisional process, implying the early Eocene closure of the Neotethys Ocean along the southern margin of the Lhasa terrane. © 2020 Geological Society of America
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184680
作者单位	Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China; State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210046, China; Department of Geological Sciences, University of Florida, 241 Williamson Hall, Gainesville, Florida 32611, United States
推荐引用方式 GB/T 7714	Ma X.,Xu Z.,Meert J.G.,et al. Early Eocene High-flux Magmatism and Concurrent High-temperature Metamorphism in the Gangdese Belt, Southern Tibet[J],2021,133.
APA	Ma X.,Xu Z.,Meert J.G.,Tian Z.,&Li H..(2021).Early Eocene High-flux Magmatism and Concurrent High-temperature Metamorphism in the Gangdese Belt, Southern Tibet.Bulletin of the Geological Society of America,133.
MLA	Ma X.,et al."Early Eocene High-flux Magmatism and Concurrent High-temperature Metamorphism in the Gangdese Belt, Southern Tibet".Bulletin of the Geological Society of America 133(2021).