摘要
武山铜矿床是长江中下游成矿带九瑞矿集区内典型的层控-接触带矽卡岩型铜多金属矿床,铜资源量达到大型,此外还共生硒、碲、钴、镓、铊等关键金属矿产,具备良好的矿产资源综合利用前景,但矿床中关键金属的分布规律、赋存状态和富集机制等研究尚未开展。本文以武山铜矿床为研究对象,系统采集了矿床南矿带接触带矽卡岩型矿体3条勘探线(W3-2、S4-2、N6-1)、北矿带层控硫化物型矿体3条勘探线(E9-2、E2-1、W4-1)和层控矽卡岩型矿体1条勘探线(E7-3)代表性岩矿石样品。通过光学显微镜和扫描电镜的观察,结合全岩地球化学和矿物原位LA-ICP-MS分析,查明了矿床中硒、碲、钴等关键金属的空间分布规律与赋存状态,初步探讨了硒、碲、钴的迁移沉淀机制。研究结果表明矿床中伴生硒、碲、钴的估算资源量分别为5513t、611t和9597t,均达到大-中型规模;武山矿床是成矿带内硒含量最高、潜在资源量最大的矿床。北矿带矿体中Se、Te、Co含量明显高于南矿带,北矿带中部成矿中心向东西远端,矿体中Se、Te、Co含量规律性增高。矿石中Se、Te、Co含量与S含量具有较强的正相关性,矿石中硫化物的含量是关键金属含量主要控制指标;Se和Co富集于含铜黄铁矿矿石、含铜白云岩矿石、含铜矽卡岩矿石(高硫)中;Te富集于含铜黄铁矿矿石和含铜白云岩矿石中。矿床中硒、碲主要以独立矿物和硫化物中类质同象替换两种赋存形式,钴则主要以Co^(2+)类质同象形式进入黄铁矿矿物晶格。矿床中硒、碲随着成矿流体温度降低、硫逸度升高、氧逸度降低、pH值升高逐渐沉淀富集;钴主要随着硫化物的沉淀富集在黄铁矿中。
The Wushan copper deposit is a typical stratiform-contact skarn-type copper polymetallic deposit in the Jiurui ore cluster of the Middle and Lower Reaches of the Yangtze River Metallogenic Belt.The copper reserves of the deposit are large,along side the presence of essential metal minerals including selenium,tellurium,cobalt,gallium,and thallium,suggesting promising opportunities for the comprehensive utilization of mineral resources.Nevertheless,there remains a dearth of research regarding the distribution patterns,occurrence states,and enrichment mechanisms of these key metals within the deposit.In this study,representative rocks and ore samples were collected from three exploration lines(W3-2,S4-2,N6-1)of the contact zone skarn-type ore body in the southern mining area,three exploration lines(E9-2,E2-1,W4-1)of the stratiform sulfide-type ore body and one exploration line(E7-3)of the stratiform skarn-type ore body in the northern mining area.The spatial distribution patterns and occurrence states of selenium,tellurium,cobalt and other key metals in the deposit were investigated by using optical microscopy,scanning electron microscopy,whole-rock chemical analysis,and in-situ LA-ICP-MS trace element testing.Additionally,the migration and precipitation mechanisms of selenium,tellurium and cobalt were preliminarily discussed.The results showed that the estimated resource reserves of selenium,tellurium and cobalt in the deposit amounting to 5513t,611t and 9597t,respectively,all reaching large to medium scales.The Wushan deposit has the highest selenium content and the largest selenium potential resource among the metal deposits in the metallogenic belt.Furthermore,the Se,Te and Co contents in the northern ore bodies,where significantly higher than that in the southern mining area,increased regularly from the central mineralization center towards the east and west ends of the northern mining area.Meanwhile,a strong positive correlation was observed between the concentrations of Se,Te,and Co in the ore and the S content,with the sulfide content serving as the primary controlling factor for the abundance of key metals in the ore.Besides,selenium and cobalt were predominantly concentrated in chalcopyrite-type,copper-bearing skarn-type(high sulfur)and copper-bearing dolomite-type ores.Tellurium,on the other hand,was mainly enriched in chalcopyrite-type and copper-bearing dolomite-type ores.Selenium and tellurium were mainly present in the form of isomorphic substitution in independent minerals and sulfides,whereas cobalt mainly incorporated into the lattice of pyrite minerals in the form of Co^(2+)isomorphic substitution.Selenium and tellurium gradually precipitated and enriched as the temperature of the mineralizing fluid decreased,the sulfur fugacity increased,the oxygen fugacity decreased,and the pH value increased,while cobalt mainly enriched within pyrrhotite through sulfides precipitate.
作者
陈希泉
周涛发
王彪
刘鑫
彭康
CHEN XiQuan;ZHOU TaoFa;WANG Biao;LIU Xin;PENG Kang(Ore Deposit and Exploration Centre(ODEC),School of Resources and Engineering,Hefei University of Technology,Hefei 230009,China;School of Resources,Environment and Jewelry,Jiangxi College of Applied Technology,Ganzhou 341000,China;Anhui Province Engineering Research Center for Mineral Resources and Mine Environments,Hefei 230009,China;MNR Key Laboratory of Ionic Rare Earth Resources and Environment,Jiangxi College of Applied Technology,Ganzhou 341000,China;Jiangxi Copper Corporation Limited Wushan Copper Mine,Ruichang 332200,China)
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2023年第10期3121-3138,共18页
Acta Petrologica Sinica
基金
国家自然科学基金项目(91962218)
国家重点研发计划项目(2022YFC2903503)
中央高校基本科研业务费专项(JZ2023HGQB0153)联合资助.
关键词
关键金属
矿化规律
赋存状态
沉淀机制
武山铜矿床
长江中下游成矿带
Dissipated metal
Mineralization regularity
Occurrence
Precipitation mechanism
Wushan copper deposit
The Middle and Lower Reaches of the Yangtze River Metallogenic Belt
