云南省卓潘碱性杂岩体矿物学、地球化学特征及其地质意义
Mineralogical and Geochemical Characteristics of the Zhuopan Alkaline Complex in Yunnan Province and Their Geological Significance

摘要： 卓潘杂岩体是金沙江—哀牢山富碱侵入岩带的重要组成部分，位于兰坪盆地西部。岩体主要由辉长岩、辉石岩及正长岩组成，各岩石的K2O含量为096%～736%，Na2O含量为052%～662%，Na2O+K2O含量为198%～897%，K2O/Na2O比值介于035～1115之间，属于高钾、富碱的钾玄岩系列。岩石中的辉石为透辉石，长石主要为钠长石(An＜5)和正长石，黑云母为镁质黑云母。计算获得辉石的结晶温度范围介于1 070～1 490 ℃之间。各矿物成分特征表明卓潘杂岩体属于富铁、高氧逸度的岩浆体系，形成于后碰撞的挤压环境向伸展环境转换的构造背景。
Abstract: The Zhuopan alkaline complex is located in the western Lanping basin and is an important part of the JinshajiangAilaoshan alkalirich intrusion belt. The Zhuopan alkaline complex is mainly composed of gabbro, pyroxenolite and syenite,and their K2O contents of the whole rock vary from 198% to 897%; the Na2O contents are from 052% to 662%, the Na2O+K2O contents are from 198% to 897% and the K2O/Na2O ratios change between 035 and 1115, indicating that they belong to the high K, alkalirich shoshonite series.Electron microprobe analysis(EMPA)indicates that the pyroxene is dominated by the diopside; the feldspar is mainly albite (An<5) and orthoclase feldspar; and biotite is Mgbiotite in the complex rock.Pyroxene thermometer calculation shows that the crystallization temperature was from 1,070 to 1,490 ℃.According to the geochemical characteristics of the different rocks and minerals,we deduce that the Zhuopan alkaline complex was sourced from a magmatic system with high oxygen fugacity and iron content and formed in a transition tectonic setting changing from post collisional compression to extensional environment