气候变化领域集成服务门户(CCPortal): Triassic record of Paleo-Tethyan subduction: Evidence from prograde metamorphic P-T paths of the Baqing eclogite, eastern Qiangtang, central Tibet

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DOI	10.1080/00206814.2023.2172742
	Triassic record of Paleo-Tethyan subduction: Evidence from prograde metamorphic P-T paths of the Baqing eclogite, eastern Qiangtang, central Tibet
	Wei, Xin; Jin, Xin; Zhang, Yu-Xiu; Yan, Li-Long
发表日期	2023
ISSN	0020-6814
EISSN	1938-2839
起始页码	3087
结束页码	3099
卷号	65 期号:20
英文摘要	The prograde metamorphic P-T conditions of eclogites correspond to the subduction processes of oceanic plates. The conditions may be recorded in mineral inclusions and the compositional zoning of garnets, and they play significant roles in revealing the dehydration depth, geothermal structure of the subduction plate and in understanding arc magmatism. The P-T conditions of the Baqing eclogite have been determined previously using traditional geothermobarometers and Ti-in-zircon geothermometers. To obtain more precise prograde metamorphic P-T conditions and details of the Paleo-Tethyan subduction process, we carried out phase equilibrium modeling using a newly collected Baqing eclogite sample. The sample is characterized by well-developed prograde zoning in metamorphic garnets with increasing Mg and decreasing Mn contents from cores to rims, a peak metamorphic mineral assemblage of garnet + omphacite + phengite + rutile + quartz, and a retrograde metamorphic mineral assemblage of amphibole + plagioclase that replaced omphacite. We calculated the peak metamorphic conditions of the Baqing eclogite using the Garnet-Omphacite-Phengite-Quartz thermobarometers to be 26.5 +/- 1 kbar and 730 +/- 60 degrees C, consistent with the results (23.5-27.5 kbar, 730-750 degrees C) calculated using a P-T pseudosection. The prograde metamorphic P-T conditions were constrained to similar to 21.4 kbar and similar to 580 degrees C using pyrope and grossular isopleths. These results are consistent with previous calculations for the Baqing eclogite. Eclogites of the Central Qiangtang metamorphic belt, the Baqing metamorphic complex, and Changning-Menglian metamorphic belt show parallel P-T paths with different geothermal gradients, that relate to their different protoliths but similar heating and burial processes during Triassic subduction of the Shuanghu Paleo-Tethyan oceanic plate.
关键词	Prograde metamorphism subduction process the Baqing metamorphic complex pseudosections Tibetan tethys
英文关键词	NORTHERN TIBET; HIGH-PRESSURE; SUTURE ZONE; GARNET; CHINA; BEARING; ROCKS; GEOCHEMISTRY; CONSTRAINTS; EXHUMATION
WOS研究方向	Geology
WOS记录号	WOS:000932102900001
来源期刊	INTERNATIONAL GEOLOGY REVIEW
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283443
作者单位	Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Tongji University; Chinese Academy of Sciences; Institute of Oceanology, CAS; China Geological Survey; Institute of Geology, Chinese Academy of Geological Sciences; Chinese Academy of Geological Sciences; Ministry of Natural Resources of the People's Republic of China; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS
推荐引用方式 GB/T 7714	Wei, Xin,Jin, Xin,Zhang, Yu-Xiu,et al. Triassic record of Paleo-Tethyan subduction: Evidence from prograde metamorphic P-T paths of the Baqing eclogite, eastern Qiangtang, central Tibet[J],2023,65(20).
APA	Wei, Xin,Jin, Xin,Zhang, Yu-Xiu,&Yan, Li-Long.(2023).Triassic record of Paleo-Tethyan subduction: Evidence from prograde metamorphic P-T paths of the Baqing eclogite, eastern Qiangtang, central Tibet.INTERNATIONAL GEOLOGY REVIEW,65(20).
MLA	Wei, Xin,et al."Triassic record of Paleo-Tethyan subduction: Evidence from prograde metamorphic P-T paths of the Baqing eclogite, eastern Qiangtang, central Tibet".INTERNATIONAL GEOLOGY REVIEW 65.20(2023).