摘要
通过长安金矿床不同类型矿石、岩浆岩和白云岩地层稀土元素地球化学对比研究,结合显微镜蚀变矿化特征观察,对该矿床与不同类型地质体成因关系进行讨论。石英正长斑岩、正长斑岩、正长岩、煌斑岩、辉绿岩稀土配分曲线均为右倾型,配分模式相似,指示矿区内三类长英质岩石和中基性煌斑岩、辉绿岩可能为同源岩浆演化产物。毒砂矿化原生矿石与弱黄铁矿化原生矿石相比,Eu负异常程度低,而矿区内煌斑岩与辉绿岩具有弱负Eu异常,指示毒砂矿化作用可能与煌斑岩与辉绿岩岩浆活动有关。黄铁矿化白云岩比无蚀变白云岩稀土元素总量(∑REE)要高,但两者稀土配分模式基本一致,指示黄铁矿化成矿热液稀土元素特征与白云岩稀土元素特征相似,推断黄铁矿化热液可能来源于白云岩变质热液。
Combined micro-observation and rare earth elements （REE） studies of different types of gold ores, diverse magmatic rocks and dolomite rocks of tions of gold mineralization with felsic rocks, Chang ＇ an gold deposit in south Yunnan province, we discuss the correladiabase, lamprophyre and dolostone. Quartz orthophyre, orthophyre, syenite diabase and lamprophyre show similar REE characteristics which indicate their possible same origin and source. Arsenopyrite mineralized ores show less Eu anomalies than the weak pyrite mineralized ores. This indicates that the ore fluids responsible for gold mineralization related to arsenopyrite should be of no obvious or positive Eu anomalies.For diabase and lamprophyre showing no obvious Eu anomalies, we deduce the gold mineralization fluids related to arsenopyrite should be related to magmatic activities that formed the diabase and lamprophyre veins. REE characteristics comparision of dolostones with and without pyrite mineralization indicates that metermorphic hydrothermal fluid from dolostone might be related to gold mineralization with pyrite. Combined the above suggestions, we deduce that the Chang＇an gold deposit shuold be formed by overprinting of at least two mineralization events separately triggered by medium-basic magmatic activities related to diabase and lamprophyre, and by metermorohic hydrothermal fluid related to regional dolostone.
出处
《黄金》
CAS
北大核心
2009年第1期7-11,共5页
Gold
基金
国家自然科学基金项目(No.40572063和No.40672064)
教育部创新团队
"111"计划(No.B07011)
教育部"跨世纪人才培养计划"
云南地矿资源股份有限公司地质科研项目(No.ykgf2006-ky1-ky2)
中国地质大学地质过程与矿产资源国家重点实验室开放基金(No.GPMR0732)联合资助
关键词
长安金矿床
稀土元素
叠加成矿
地质意义
Chang an gold deposit
rare earth element
overprinting mineralization
geological significance
