石英显微构造阴极发光特征研究——以西藏甲玛岩体为例  

The Characteristics of Cathodoluminescence-Visualized Microstructure in Quartz:A Case Study from the Jiama Igneous Rock in Tibet

作　　者：彭惠娟[1] 汪雄武[1] 唐菊兴[2] 秦志鹏[1] 侯林[1] 周云[1] 

机构地区：[1]成都理工大学地球科学学院,成都610059 [2]中国地质科学院矿产资源研究所,北京100037

出　　处：《矿物岩石地球化学通报》2010年第3期279-283,共5页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家科技支撑项目(2006BAB01A01);中金集团公司青藏专项(1212010818089);西藏自治区矿产资源潜力评价(1212010813025);成都理工大学矿物学岩石学矿床学国家重点(培育)学科建设项目

摘　　要：根据石英在阴极射线下显示的生长结构差异,可以区分不同世代的石英斑晶,揭示岩浆演化过程。本次研究以西藏甲玛岩体中石英斑晶为例,采用光学显微镜阴极发光仪(OM-CL)和扫描电镜阴极发光仪(SEM-CL)。研究表明甲玛矿区中基性岩体有5个世代的石英斑晶。早期石英斑晶至少经历了两次岩浆混合作用:第一次基性岩浆的混入,石英斑晶核部形成了浑圆状重熔表面,然后石英经历了较稳定的生长阶段,形成均匀的生长环带;随着岩浆的快速上升侵位,岩浆储层中压力减小,导致第二次基性岩浆混入,形成富Ti的波状、港湾状重熔表面和石英钾长石外壳。Cathodoluminescence is an effective method for studying micro structures of quartz.We studied igneous rocks of JiaMa in Tibet by using two scanning electron microscope cathodoluminescence（SEM-CL） and optical microscope CL（OM-CL）.The results indicate that there are five generations of quartz phenocrysts.Early-magmatic quartz phenocrysts have gone through at least two times of magma mixing events.Owing to the first mixing with mafic magma,resorption surfaces appeared around the core of quartz phenocrysts.And then,the quartz has experienced stable growth conditions,forming a steady growth zone with low CL contrasts.The rapid ascent of magma was accompanied by second magma mixing event,which caused wavy（or embayed） resorption surfaces with Ti-rich overgrowth and K-feldspar-quartz mantle.

关 键 词：阴极发光 石英 显微结构 岩浆混合 

分 类 号：P578.494[天文地球—矿物学]