摘要
根据野外对从江翁浪地区蚀变岩型金矿床内岩石变形特点的分析,在典型剖面中划分出了3个不同的构造变形带,即简单变形带(未蚀变带)、复杂透镜体带(强蚀变带)和叠加透镜体带(弱蚀变带)。不同构造带中Au的含量不同,其特点为:复杂透镜体带>叠加透镜体带>简单变形带,即Au在构造变形强烈的区域富集。对3个变形带内的常量元素迁移规律和稀土元素特征进行了探讨:①常量元素的迁移规律明显,从叠加透镜体带和复杂透镜体带到简单变形带,明显带出的主要成分为SiO2、MnO、K2O、FeO、TiO2,说明引起蚀变的流体中富含SiO2、MnO等;而P2O5、Fe2O3、MgO、Na2O、CaO等成分明显带入,说明矿化作用导致P2O5、Fe2O3等向矿体迁移富集。②简单变形带的稀土元素总量高于叠加透镜体带和复杂透镜体带,稀土元素配分曲线为右倾型,轻稀土元素富集。δEu都小于1以及δCe都大于1,说明该矿区的成矿环境为氧化性质环境。该矿床样品的稀土元素配分曲线图显示出,大部分矿体和围岩的曲线以及石英脉的曲线与辉绿岩的曲线基本相同,说明矿体的成矿物质大部分来源于深部;矿体与围岩有小部分曲线趋于相同,可认为矿体的成矿物质有小部分来自于围岩。最后,对金的富集机制进行了简要的论讨,认为元素在成矿过程中的迁移能力受到动力变形机制以及元素自身离子半径的影响。
Based on field characteristics of the Wenglang structural altered rock type gold deposit,the authors recognized three different tectonic deformation belts in the typical profile,namely simple deformation belt（unaltered belt）,superimposed lens belt（weakly altered belt） and complicated lens belt（strongly altered belt）.The variation of Au content in the three different tectonic deformation belts is in order of complicated lens belt 〉superposed lens belt〉 simple deformation belt.An analysis of major element migration regularity and REE characteristics in these belts has led to the following conclusions： ① The migration regularity of major elements is obvious.The major components which migrated from the complicated deformation belt and the superimposed lens belt into the simple deformation belt included SiO2,MnO,K2O,FeO and TiO2,suggesting that the liquids with abundant SiO2,MnO etc.could cause alteration.The components P2O5,Fe2O3,MgO,Na2O and CaO were obviously brought in,implying that mineralization made such major components as P2O5 and Fe2O3 move into and concentrated in the ore body.② Total REE quantity in the simple deformation belt is above the superimposed lens belt and the complicated deformation belt.The rare earth element curves assume a rightly dipping REE pattern and the enrichment of LREE.δEu values are all lower than 1,whereas δCe values are all higher than 1.The mineralization took place in an oxidation environment.The REE patterns show that most curves of the ore body and wall rock are basically the same as those of quartz veins and diabase.It turns out that the source of ore-forming materials was derived from the depth.A few curves of the ore body and wall rock tend to be similar to each other.All these data indicate that the source of the ore-forming material partly came from the wall rock.The mechanism for gold enrichment is also briefly discussed.It is held that the element migration capability in the ore-forming process depended on two factors,namely dynamic deformation me
出处
《矿床地质》
CAS
CSCD
北大核心
2010年第3期489-500,共12页
Mineral Deposits
基金
贵州省2006年度研究生创新基金资助项目(编号:省研理工2006003)的资助
关键词
地球化学
常量元素
稀土元素
构造分带
迁移规律
翁浪金矿
贵州省
geochemistry
major elements
REE
tectonic sections
migration regularity
Wenglang gold deposit
Guizhou Province
