西藏雅鲁藏布江缝合带西段龙拉多蛇绿岩成因及其动力学背景OA
Genesis and Geodynamic Setting of the Longladuo Ophiolite from the Western Section of the Yarlung-Zangbo Suture Zone,Xizang
雅鲁藏布江缝合带不同区段均发育具有洋岛玄武岩(OIB)型特征的蛇绿岩,对这类 OIB 型蛇绿岩的成因机制及其构造意义尚未形成系统性的研究成果.本文研究工作聚焦于缝合带西段龙拉多地区新发现的 OIB型蛇绿岩,对其开展了年代学与岩石地球化学分析.研究结果表明,龙拉多蛇绿岩成岩时代为 140～142 Ma,形成于板内拉张构造环境,其母岩浆由含尖晶石和石榴子石二辉橄榄岩约 10%部分熔融形成,在岩浆演化过程中经历了橄榄石、辉石等矿物的分离结晶.雅鲁藏布江缝合带 OIB 型蛇绿岩可能来源于晚侏罗世—早白垩世时期洋盆扩张阶段的地幔柱岩浆作用.
OIB-type ophiolites have formed in different sections along the Yarlung-Zangbo Suture Zone.However,research results regarding the genetic mechanisms and tectonic settings of OIB-type ophiolites are debatable.This study focused on the geochemistry and geochronology of newly discovered OIB-type ophiolites in the Longladuo area of the western section of the suture zone.The results showed that the Longladuo ophiolites formed during 140-142 Ma in an intraplate extensional tectonic environment.The parental magma was formed by the partial melting of approximately 10%spinel and garnet lherzolite.During the magmatic evolution process,it experienced fractional crystallization of minerals such as olivine and pyroxene.The OIB-type ophiolites in the Yarlung-Zangbo Suture Zone may have originated from the mantle plume magmatism during the ocean basin expansion stage in Late Jurassic-Early Cretaceous.
侯云岭;贺娟;陈颖辉;李江寒
滇西应用技术大学图书馆,云南 大理 671000滇西应用技术大学建筑工程学院,云南 大理 671000大理白族自治州水利水电勘测设计研究院,云南 大理 671014滇西应用技术大学建筑工程学院,云南 大理 671000
天文与地球科学
雅鲁藏布江缝合带蛇绿岩地球化学地质年代学西藏南部
Yarlung-Zangbo suture zoneophiolitegeochemistrygeochronologysouthern Xizang
《地球学报》 2026 (3)
629-643,15
本文由云南省教育厅科学研究基金项目(编号:2023J1278)、云南省科技厅基础研究专项面上项目(编号:202301AT070012)、滇西应用技术大学人才引进科研启动项目(编号:2022RCKY0004)联合资助. This study was supported by Yunnan Provincial Department of Education Scientific Research Fund(No.2023J1278),Yunnan Fundamental Research Projects(No.202301AT070012),and West Yunnan University of Applied Sciences(No.2022RCKY0004).
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