| 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 |
| 点此下载全文 |
| 引用本文：侯云岭,贺娟,陈颖辉,李江寒.2026.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[J].地球学报,47(3):629-643. |
| DOI：10.3975/cagsb.2025.072321 |
| 摘要点击次数: 395 |
| 全文下载次数: 33 |
|
| 基金项目: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。 |
|
| 中文摘要: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。 |
| 中文关键词:雅鲁藏布江缝合带 蛇绿岩 地球化学 地质年代学 西藏南部 |
| |
| Genesis and Geodynamic Setting of the Longladuo ophiolite from the Western Section of the Yarlung-Zangbo Suture Zone, Xizang |
|
|
| Abstract: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. |
| keywords:Yarlung–Zangbo suture zone ophiolite geochemistry geochronology southern Xizang |
| 查看全文 查看/发表评论 下载PDF阅读器 |
