新疆拜城县波孜果尔A型花岗岩类矿物学特征及岩浆形成的温度条件  

Mineralogy and temperature of magma generation for A-type granitoids in Boziguoer,Baicheng County,Xinjiang

作　　者：刘春花[1] 尹京武[2] 吴才来[1] 蔡佳[1] 邵兴坤[2] 杨海涛[2] 郜源红[1] 雷敏[1] 徐海明[3] 王军[3] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质大学,北京100083 [3]中国地质科学院矿产资源研究所,北京100037

出　　处：《岩石矿物学杂志》2012年第4期589-602,共14页Acta Petrologica et Mineralogica

基　　金：国家专项(SinoProbe-05-05);自然科学基金项目(40921001;49772106;40472034;40672049);中国地调局项目(1212010918007;1212010818090;1212010611803;1212010711816;1212011120160)

摘　　要：新疆拜城县波孜果尔A型花岗岩类为富含铌、钽、锆等有用元素的含矿岩体。通过偏光显微镜、电子探针（EPMA）化学成分分析、电子探针背散射（BSE）对波孜果尔A型花岗岩类的矿物学特征进行了研究,并对岩浆形成的温度条件与构造背景进行了讨论。结果表明,波孜果尔A型花岗岩类包括霓石钠闪石英碱性长石正长岩、霓石钠闪碱性长石花岗岩、黑云母碱性长石正长岩3种岩石类型。主要造岩矿物包括石英、钠长石、钾长石、霓石、钠铁闪石和铁叶云母。副矿物包括锆石、烧绿石、钍石、萤石、独居石、氟碳铈镧矿、磷钇矿等。岩浆平均温度832~839℃,形成于非造山的板内构造环境,且具高温、无水、低氧逸度的成岩特点。The Boziguoer A-type granitoids in Baicheng County of Xinjiang are ore-bearing rocks with abundant useful elements such as Nb,Ta and Zr.The petrological and mineralogical characteristics of the A-type granitoids were investigated on the basis of observation under polarized microscope,chemical analysis and detailed BSE images using EPMA,followed by the discussion on the p-T conditions of A-type magma generation and the tectonic setting.The results indicate that these A-type granitoids could be divided into three types,namely aegirine arfvedsonite quartz alkali feldspar syenite,aegirine arfvedsonite alkali feldspar granite and biotite alkali feldspar syenite.The major rock-forming minerals are quartz,albite,K-feldspar,aegirine,arfvedsonite and siderophyllite,whereas the accessory minerals include mainly zircon,pyrochlore,thorite,fluorite,monazite,bastnaesite and xenotime.The average temperatures of the magma are 832～839℃.A-type granitoids might have been formed in an anorogenic intraplate tectonic setting by which they generally show such features as hightemperature,anhydrous nature and low fugacity.

关 键 词：碱性岩 A型花岗岩类 矿物学 波孜果尔 

分 类 号：P588.121[天文地球—岩石学]