气候变化领域集成服务门户(CCPortal): Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens

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DOI	10.1029/2019JB019119
	Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens
	Kang D.; Zhang Z.; Palin R.M.; Tian Z.; Dong X.
发表日期	2020
ISSN	21699313
卷号	125 期号:6
英文摘要	The Himalayan orogen, which formed due to collision of the Indian and Asian continents during the Early Tertiary, is a prime example of a large, hot collisional orogen. Despite decades of study, the duration of partial melting of migmatitic rocks exposed in the Himalayan orogenic core remains highly controversial. As such, we have performed detailed petrological and geochronological analyses of garnet amphibolite from the eastern Himalayan syntaxis in order to reveal the thermal conditions, tectonometamorphic mechanisms, and timing and duration of anatexis in metabasic rocks that form a major component of the thickened lower crust of the eastern Himalayan orogen. Phase equilibrium modeling and geothermobarometry show that the studied sample underwent high-pressure granulite-facies metamorphism and partial melting at 15−17 kbar and 805−840°C. Dehydration melting of amphibole during prograde metamorphism generated up to 20 vol. % partial melt with a granitic composition, which thus represents a potential source for Himalayan syn- to post-orogenic crustal-derived granites. Zircon U-Pb geochronology shows that the garnet amphibolite witnessed a long-lived anatectic and melt crystallization process lasting more than 30 Myr. Prolonged anatexis from ca. 40 to ca. 20 Ma predates initiation of the extrusion of Himalayan metamorphic core by up to 15 Myr, indicating that the thick and weak crust of the Himalayan-Tibetan orogen must have remained stationary for this length of time, despite the ongoing continental collision. This study thus provides new insight into the tectonic evolution of hot orogens. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	eastern Himalaya; garnet amphibolite; large hot orogen; partial melting; tectonic evolution; timescales
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187797
作者单位	School of Earth Science and Resources, China University of Geosciences, Beijing, China; Institute of Geology, Chinese Academy of Geological Science, Beijing, China; Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO, United States
推荐引用方式 GB/T 7714	Kang D.,Zhang Z.,Palin R.M.,et al. Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens[J],2020,125(6).
APA	Kang D.,Zhang Z.,Palin R.M.,Tian Z.,&Dong X..(2020).Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens.Journal of Geophysical Research: Solid Earth,125(6).
MLA	Kang D.,et al."Prolonged Partial Melting of Garnet Amphibolite from the Eastern Himalayan Syntaxis: Implications for the Tectonic Evolution of Large Hot Orogens".Journal of Geophysical Research: Solid Earth 125.6(2020).