气候变化领域集成服务门户(CCPortal): Petrology, geochemistry and Ar-Ar geochronology of eclogites in Jinshajiang orogenic belt, Gonjo area, eastern Tibet and restriction on Paleo-Tethyan evolution

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DOI	10.31035/cg2023025
	Petrology, geochemistry and Ar-Ar geochronology of eclogites in Jinshajiang orogenic belt, Gonjo area, eastern Tibet and restriction on Paleo-Tethyan evolution
	Tang, Yuan; Qin, Ya-dong; Gong, Xiao-dong; Li, Yong; Wang, Dong-bing; Wang, Bao-di
发表日期	2023
ISSN	2096-5192
起始页码	285
结束页码	302
卷号	6 期号:2
英文摘要	As one of the important Paleo-Tethys suture zones in eastern Tibet, the Jinshajiang orogenic belt is of great significance to study the tectonic evolution of the main suture zone of Paleo-Tethys. In this paper, eclogites developed in the Jinshajiang suture zone in Gonjo area, eastern Tibet, are selected as specific research objects, and petrological, geochemical and Ar-Ar geochronological analyses are carried out. The major element data of the whole rock reveals that the eclogite samples have the characteristics of picritic basalt-basalt and belong to the oceanic low potassium tholeiites. The results of rare earth elements and trace elements of the samples show that the protoliths of eclogites have characteristics similar to oceanic island basalt (OIB) or normal mid ocean ridge basalt (N-MORB). Muscovite (phengite) from two eclogite samples yield the Ar-Ar plateau ages of 247 & PLUSMN;2 Ma and 248 & PLUSMN;2 Ma respectively, representing the peak metamorphic age of eclogite facies and the timing of complete closure of the Jinshajiang Paleo-Tethys Ocean. Muscovite and biotite selected from the hosting rocks of eclogite yield the Ar-Ar plateau ages are 238 & PLUSMN;2 Ma and 225 & PLUSMN;2 Ma respectively, reflecting the exhumation age of eclogites and their hosting rocks. Combined with the zircon U-Pb dating data (244 Ma) of eclogites obtained in previous work, it can be concluded that the Jinshajiang Paleo-Tethys ocean was completely closed and arc-continent collision was initiated at about 248 -244 Ma (T21). Subsequently, due to the large-scale arc (continent)-collision orogeney between Deqin-Weixi continental margin arc and Zhongza block (T31-T32), the eclogites were rapidly uplifted to the shallow crust.
关键词	Eclogite Ar -Ar geochronology Closure of Paleo-Tethys ocean Arc-continent collision Geological survey engineering Jinshajiang orogenic belt Eastern Tibet
英文关键词	ZIRCON U-PB; SUTURE ZONE; TECTONIC EVOLUTION; TRIASSIC COLLISION; AILAOSHAN SUTURE; PLATEAU-EVIDENCE; SOUTH CHINA; SW CHINA; ROCKS; SUBDUCTION
WOS研究方向	Geosciences, Multidisciplinary
WOS记录号	WOS:001017235200001
来源期刊	CHINA GEOLOGY
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/282895
作者单位	Ministry of Natural Resources of the People's Republic of China; China Geological Survey; Chengdu Center, China Geological Survey
推荐引用方式 GB/T 7714	Tang, Yuan,Qin, Ya-dong,Gong, Xiao-dong,et al. Petrology, geochemistry and Ar-Ar geochronology of eclogites in Jinshajiang orogenic belt, Gonjo area, eastern Tibet and restriction on Paleo-Tethyan evolution[J],2023,6(2).
APA	Tang, Yuan,Qin, Ya-dong,Gong, Xiao-dong,Li, Yong,Wang, Dong-bing,&Wang, Bao-di.(2023).Petrology, geochemistry and Ar-Ar geochronology of eclogites in Jinshajiang orogenic belt, Gonjo area, eastern Tibet and restriction on Paleo-Tethyan evolution.CHINA GEOLOGY,6(2).
MLA	Tang, Yuan,et al."Petrology, geochemistry and Ar-Ar geochronology of eclogites in Jinshajiang orogenic belt, Gonjo area, eastern Tibet and restriction on Paleo-Tethyan evolution".CHINA GEOLOGY 6.2(2023).