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

作　　者：李腾建 张静[1] 佟子达 潘泽伟 

机构地区：[1]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [2]云南省地质调查局,云南昆明650051

出　　处：《现代地质》2017年第3期474-485,共12页Geoscience

基　　金：国家"973"计划项目(2015CB452604)

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K_2O含量为0.96%~7.36%,Na_2O含量为0.52%~6.62%,Na_2O+K_2O含量为1.98%~8.97%,K_2O/Na_2O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。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 K20 contents of the whole rock vary from 1.98% to 8.97% ; the Na20 con- tents are from 0.52% to 6.62% , the Na20 ＋ K20 contents are from 1.98% to 8.97% and the K20/Na20 ratios change between 0. 35 and 11.15, indicating that they belong to the high K, alkali-rich shoshonite series. Elec- tron microprobe analysis（EMPA）indicates that the pyroxene is dominated by the diopside; the feldspar is main- ly 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 geochemi- cal 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.

关 键 词：卓潘碱性杂岩体 电子探针 辉石 黑云母 长石 云南省 

分 类 号：P588.12[天文地球—岩石学]