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位于扬子克拉通西缘的新元古代宝兴杂岩主要由中低级变质的辉长质片麻岩、闪长质片麻岩、英云闪长质到花岗闪长质片麻岩和块状二长花岗岩组成。岩石地球化学和Sm-Nd同位素特征表明,辉长质片麻岩和闪长质片麻岩为同源岩浆演化序列,原始岩浆起源于亏损地幔尖晶石橄榄岩的部分熔融,在上升和侵位过程中受到了地壳岩石强烈混染。英云闪长质和花岗闪长质岩浆形成于下地壳玄武质岩石部分熔融,而二长花岗质岩浆形成于杂砂岩的部分熔融。综合分析宝兴杂岩的岩石组合、微量元素和同位素特征,该杂岩体最有可能形成于新元古代活动大陆边缘火山弧构造背景,并可能经历了碰撞过程。
The Neoproterozoic Baoxing complex located at the western margin of the Yangtze craton is mainly composed of middle-low grade gabbro, dioritic gneisses, dacite diorites to granodiorite gneiss and blocks Composed of two long granite. Petrogeochemistry and Sm-Nd isotopic characteristics show that the gabbro gneisses and dioritic gneisses are homologous magmatic evolution sequences. The original magma originates from the partial melting of the depleted mantle spinel peridotites, Bit by the strong crustal rock contamination. The Yingyun dioritic and granodioritic magma formed partly in the lower crust basaltic rocks, and the part of the second granitic magma formed in the miscellaneous sandstone melted. Based on the comprehensive analysis of the rock assemblages, trace elements and isotopic characteristics of the Baoxing complex, the complex is most likely formed in the volcanic arc tectonic setting of Neoproterozoic continental margin and may have undergone a collision process.