云南维西大宝山铜多金属矿床地质特征与成矿期次分析

Geological characteristics and Analysis on Metallogenic stages of the Dabaoshan Copper-polymetallic Deposit in Weixi,Yunnan

云南维西大宝山铜多金属矿床位于青藏高原东南缘哀牢山-金沙江构造带之“三江”成矿带中,为一处典型受构造控制的浅成热液矿床。矿床内不同矿段具有不同的矿石组合类型,相同矿段不同埋深亦具有不同的矿石组合类型。其中望香台矿段由深至浅主要为辉铜矿、白云石(铁白云石)组合,辉铜矿(铜蓝)、孔雀石、白云石组合及孔雀石、蓝铜矿、辉铜矿、褐铁矿、石英组合;滑石板矿段由深至浅主要为黄铜矿、黄铁矿、石英组合,辉铜矿、白云石(铁白云石)组合类型。依据矿石组合类型将矿床成矿期划分为岩浆期、浅成低温热液成矿期及表生期三个成矿期和黄铁矿阶段、黄铜矿阶段、辉铜矿阶段、硫化矿混合阶段及氧化矿阶段五个成矿阶段。综合分析认为,矿体形成于含矿岩浆热液沿构造裂隙上移过程中,随着外部环境变化及外来物质的参与,富含铜、银等元素的成矿流体在有利部位富集成矿,且后期发生了强烈的次生富集及氧化还原作用。

The Dabaoshan copper-polymetallic deposit in Weixi,Yunnan is located in the"Sanjiang"metallogenic belt of the Ailaoshan-Jinshajiang structural belt in the southeastern margin of the Qinghai-Tibet Plateau.The deposit is a typical epithermal deposit controlled by structure.In this deposit,different ore sections have different ore combination types,and the same ore section has different ore types with different burial depths.For example,the Wangxiangtai ore section is mainly composed of chalcocite and dolomite(iron dolomite)assemblage from deep to shallow,chalcocite(copper blue),malachite,dolomite assemblage and malachite,azurite,chalcocite,limonite,quartz combination.The Huashiban ore section is mainly composed of chalcopyrite,pyrite and quartz from deep to shallow,and the combination type of chalcocite and dolomite(iron dolomite).According to the type of ore assemblage,the metallogenic period of the ore deposit is divided into three metallogenic periods,magmatic period,epigenetic low-temperature hydrothermal period and epigenetic period.At the same time,it is divided into five metallogenic stages:pyrite stage,chalcopyrite stage,chalcocite stage,sulfide ore mixed stage and oxide ore stage.According to the comprehensive analysis,the ore body was formed during the upward movement of the ore-bearing magmatic hydrothermal fluid along the structural fissures.With the change of the external environment and the participation of foreign substances,the ore-forming fluids rich in elements such as copper and silver were enriched and integrated into the ore at favorable positions,and later occurred.Strong secondary enrichment and redox effects.