广西龙头山金矿床赋矿岩石地球化学特征  

Geochemical Characteristics of Ore-bearing Rocks in Longtoushan Gold Deposit,Guangxi Province

作　　者：张春鹏[1] 曾南石[2] 

机构地区：[1]沈阳地质矿产研究所,辽宁沈阳110034 [2]桂林理工大学地球科学学院,广西桂林541004

出　　处：《黄金科学技术》2014年第2期17-23,共7页Gold Science and Technology

基　　金：广西自然科学基金项目"广西贵港天平山-宾阳龙头山地区成矿热液活动规律研究"(编号:桂科自0640179)资助

摘　　要：广西龙头山金矿床产于晚中生代残存的火山颈机构中。通过对金矿床火山—次火山岩的类型、空间展布及其岩石学和岩石化学等特征分析,结果表明：SiO2含量变化在62.77%~75.24%之间,La/Ce与Rb/Ti比值基本不变,稀土配分曲线为向右倾斜的富轻稀土型,同时铕亏损强烈。研究认为本区岩浆岩均属亚碱性系列英安流纹斑岩类岩石,为一套陆相中心式火山—次火山喷发—侵入岩系,形成于具有火山弧（碰撞期前）—同碰撞性质的构造环境中,具壳幔混合来源特征。Longtoushan gold deposit occurs in a late Mesozoic residual volcanic neck.The characteristics of Mesozoic volcanic-subvolcanic rocks,such as their types,space distributions and petrology etc.have been analyzed.The data of petrography and geochemistry shows that the SiO2 contents range from 62.77%to 75.24%, the La/Ce and Rb/Ti ratios are basically not changed.The right dipping of REE partitioning curves shows rich in light rare earth elements,and Europium loses a lot.These rocks are formed mainly by rhyodacitic magma,and indicate that they might result from the same magma chamber.The division of trace elements reflect that formation of the volcanic-subvolcanic rocks has a tectonic background of VGA-Syn-COLD type.The genetic series of these granitic rocks may belong to that of mixed crust-mantle derivation.

关 键 词：火山—次火山岩 岩石学 构造环境 成矿岩体 龙头山金矿 广西 

分 类 号：P618.51[天文地球—矿床学]