气候变化领域集成服务门户(CCPortal): Middle Permian and Late Triassic mafic magmatism in Nyemo area of the eastern Gangdese belt, Tibet, and its constraints on the subduction initiation of the Neo-Tethys

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DOI	10.18654/1000.0569/2023.12.06
	Middle Permian and Late Triassic mafic magmatism in Nyemo area of the eastern Gangdese belt, Tibet, and its constraints on the subduction initiation of the Neo-Tethys
	Yan LiLong; Zeng LingSen; Shen Yu; Li GuangXu; Zhao LingHao
发表日期	2023
ISSN	1000-0569
EISSN	2095-8927
起始页码	3605
结束页码	3618
卷号	39 期号:12
英文摘要	Based on the field geology and SHRIMP zircon U-Pb geochronology, we report a new occurrence of Middle Permian ( similar to 266Ma) and Late Triassic (220 similar to 219Ma) protolith age metabasic rocks near Nyemo County within the Gangdese belt. Those Late Triassic metabasic rocks also contain ca. 2. 5Ga zircon xenocrysts. Whole -rock geochemical analyses show that these metabasic rocks have similar geochemical characteristics, including: (1) enrichment in LREE and depletion in HREE and HFSE; (2) relatively consistent Sr and Nd isotope ratios (Sr-87/Sr-86( t) = 0. 703225 similar to 0.703664, epsilon(Nd)(t) = 6. 51 6. 81). In combination with the published geochemical data of the Triassic andesitic-basaltic rocks in the southeastern margin of the Lhasa Block, we conclude that the protoliths of the Nyemo metabasic rocks were formed in a continental arc environment during both the Middle Permian and the Late Triassic, and the magma that formed them originated from 2. 5% similar to 4% partial melting of the spinel-bearing peridotitic mantle and then underwent some degree of crustal assimilation. By comparing the Permian-Triassic magmatic arc records on the southwestern and southeastern margins of the Lhasa Block, we infered that the initial subduction of the Neo-Tethyan ocean beneath the Lhasa Block was diachronous. Subduction of the Neo-Tethys probably began earlier than similar to 266Ma in the eastern segment, and from 255 Ma to 214Ma in the western segment.
关键词	Lhasa terrane Metabasic rocks Neo-Tethyan ocean Subduction initiation Middle Permian Tibet
英文关键词	ZIRCON U-PB; LHASA TERRANE IMPLICATIONS; CENOZOIC VOLCANIC-ROCKS; SOUTHERN TIBET; EVOLUTION; GEOCHEMISTRY; GEOCHRONOLOGY; PETROGENESIS; BATHOLITH; ND
WOS研究方向	Geology
WOS记录号	WOS:001152994000006
来源期刊	ACTA PETROLOGICA SINICA
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283151
作者单位	China Geological Survey; Chinese Academy of Geological Sciences; Institute of Geology, Chinese Academy of Geological Sciences; China Geological Survey; Chinese Academy of Geological Sciences; National Research Center for Geoanalysis, Chinese Academy of Geological Sciences
推荐引用方式 GB/T 7714	Yan LiLong,Zeng LingSen,Shen Yu,et al. Middle Permian and Late Triassic mafic magmatism in Nyemo area of the eastern Gangdese belt, Tibet, and its constraints on the subduction initiation of the Neo-Tethys[J],2023,39(12).
APA	Yan LiLong,Zeng LingSen,Shen Yu,Li GuangXu,&Zhao LingHao.(2023).Middle Permian and Late Triassic mafic magmatism in Nyemo area of the eastern Gangdese belt, Tibet, and its constraints on the subduction initiation of the Neo-Tethys.ACTA PETROLOGICA SINICA,39(12).
MLA	Yan LiLong,et al."Middle Permian and Late Triassic mafic magmatism in Nyemo area of the eastern Gangdese belt, Tibet, and its constraints on the subduction initiation of the Neo-Tethys".ACTA PETROLOGICA SINICA 39.12(2023).