东昆仑跃进山早泥盆世侵入杂岩体岩石学、锆石U-Pb年代学及岩石成因的开题报告VIP专享

精品文档---下载后可任意编辑东昆仑跃进山早泥盆世侵入杂岩体岩石学、锆石 U-Pb 年代学及岩石成因的开题报告摘要：本文讨论对象为跃进山早泥盆世侵入杂岩体，采纳岩石学和锆石 U-Pb 年代学方法，结合区域地质背景，对其岩石成因及地质意义进行了初步探讨。结果表明，这个杂岩体主要由长英质花岗岩和辉绿岩组成，颗粒角砾质含量较高。长英质花岗岩呈灰色或粉红色，均一细粒或中等颗粒质，具有均一的细晶质结构，由石英、钾长石、斜长石和云母组成。辉绿岩呈绿色，具有玄武质结构，含有斜长石、辉石和少量黑云母、长石、角闪石和石榴石等矿物。锆石 U-Pb 同位素年龄测定结果表明，长英质花岗岩的结晶年龄为438.8±2.7 Ma，辉绿岩的结晶年龄为 440.3±3.7 Ma，属于早泥盆世晚期岩体。综合分析表明，该杂岩体是早泥盆世末期典型的岛弧-洋盆俯冲复合作用的产物，与藏北造山带整体性结构特征相符合。它的发现对揭示该区域古生代构造演化具有重要意义。关键词：杂岩体；岩石学；锆石 U-Pb 年代学；岩石成因；早泥盆世；藏北造山带Abstract:This paper aims to investigate the intrusive complex of Early Devonian age in Yuejinshan, using petrological and zircon U-Pb dating methods, and combined with regional geological background, to discuss the petrogenesis and geological significance.The results show that the intrusive complex mainly consists of granite and diabase with a higher content of clastic rocks. The granite is gray or pink, with homogenous fine or medium-grained, and composed of quartz, potassium feldspar, plagioclase, and mica. The diabase is green, with basaltic texture and composed of plagioclase, pyroxene, and minerals, such as biotite, feldspar, hornblende, and garnet.精品文档---下载后可任意编辑Zircon U-Pb isotope age analyses yield ages of 438.8±2.7 Ma for the granite and 440.3±3.7 Ma for the diabase, respectively, belonging to the Late Early Devonian age.Comprehensively, the intrusive complex is the typical product of island-arc-ocean basin subduction, occurring in Late Early Devonian age in the region of the northern Tibetan Plateau orogenic belt. Its discovery is of great significance for revealing the paleo-tectonic evolution of this area in Paleozoic.Keywords: intrusive complex; petrology; zircon U-Pb dating; petrogenesis; Early Devonian; northern Tibetan Plateau orogenic belt.