拉拉铜矿黄铁矿微量元素地球化学特征及其成因意义  

GEOCHEMICAL CHARACTERISTICS OF TRACE ELEMENTS OF PYRITE AND ITS IMPLICATIONS TO THE METALLOGENESIS IN THE LALA COPPER DEPOSIT

作　　者：周家云[1] 郑荣才[2] 朱志敏[1] 陈家彪[1] 沈冰[1] 李潇雨[1] 罗丽萍[1] 

机构地区：[1]中国地质科学院矿产综合利用研究所,四川成都610041 [2]成都理工大学"油气藏地质及开发工程"国家重点实验室,四川成都610059

出　　处：《矿物岩石》2008年第3期64-71,共8页Mineralogy and Petrology

基　　金：科技部国际科技合作项目(2005DFA20063)

摘　　要：四川会理拉拉铜矿床是我国著名大型富铜矿床，针对该矿床中黄铁矿的微量元素、稀土元素地球化学分析表明：拉拉铜矿经历了早期火山喷发成岩成矿和晚期变质成岩成矿作用。条带状矿石中的黄铁矿Co／Ni比值集中于4．92～79．2之间，落入火山成因黄铁矿区，稀土元素分布具有Eu正异常和轻稀土富集的特征，反映矿床具有伴随河口群火山喷流沉积成岩过程的同生沉积成矿作用。脉状矿石中的黄铁矿Co／Ni比值集中于1．10～3．45，落在热液成因黄铁矿区，稀土元素较河口群岩石及其他典型块状硫化物矿床矿石稀土元素更加富集轻稀土元素，稀土含量变化范围更大，显著的负Eu异常，则又说明，矿床形成的主要成矿作用是伴随新元古代晋宁运动而发生的大规模的变质作用。The Lala copper deposit is a large-size copper deposit in the Huili County, Sichuan Province. China. The analysis of trace and rare earth elements of pyrite shows that the Lala copper ore has experienced volcanic and metamorphic diagenesis mineralization. Some pyrite samples coming from zebraic ores,belong to the volcano origin because their ratio of Co/Ni ranges from 4.92 to 79.2,enriching light REE with positive Eu anomaly,reflecting that the formation of ore deposit is of sedimentary mineralization accompanied with the volcanic eruption of the Hekou group. The rest pyrite samples from vein ores is hydrothermal pyrite as their ratio of Co/Ni ranging from 1. 1 to 3.45 ,characteristic of enriching light REE,wider scope of REE content,and significant negative Eu anomaly, indicating that the main mineralization is resulted from the large scale metamorphism during the Neoproterozoic Jinning Movement.

关 键 词：拉拉铜矿 黄铁矿 微量元素 地球化学 矿床成因 

分 类 号：P588.14[天文地球—岩石学]