广东八宝铅锌银多金属矿床成矿物质来源浅析

Analysis on the Ore-forming Material Sources of Babao Pb-Zn-Ag Polymetallic Deposit in Guangdong

广东八宝铅锌银多金属矿床大地构造上处于华南褶皱系粤北凹陷带、大东山花岗岩体的南缘,是一个岩浆期后中低温热液型矿床,产于东岗岭组(D_2d)灰岩与砂岩界面上。区内构造活动强烈,岩浆作用频繁,中新生代的岩浆活动为本区提供了大量的成矿流体和热源,从大地构造位置和岩浆活动情况来看,对成矿十分有利。钻探工程揭露发现深部隐伏花岗岩体的存在,同时在矿区北东部有燕山三期中—细粒花岗岩(γ_5^(2(3)))岩体(八宝岩体),其银、钼、铜、铅、钨、镍、铷等的背景值较高,推测为矿床的形成提供了成矿物质。

Babao Pb-Zn-Ag polymetallic deposit is regionally located at the northern Guangdong depression zone of the South China Fold System,and the southern margin of Dadongshan granite pluton.It belongs to low or medium temperature postmagmatic hydrothermal deposit,which produced on the interface of limestone and sandstone of Dondgangling Formation（D2d）.In this area the tectonic activity was intense,and the magmatism was frequen.Thus,the Mesozoic Cenozoic magmatic activity provided abundant ore-forming fluid and heat,which was very advantageous to its mineralization regarding from geotectonic location and magmatic activity.Drilling engineering revealed the existence of the concealed granite in the depth,and the background values of Ag,Mo,Cu,Pb,W,Ni are higher in the middle-fine-grained granite of third stage of Yanshanian Period（γ_5^（2（3））） in the northeastern of the deposit,which is suggested to provide the ore-forming material for the ore bed.