摘要
西岔金银矿床为早白垩世中温热液脉型,主要产金,伴生银。成矿过程先后经历了热液成矿期和表生成矿期。其中,热液成矿期可划分为3个成矿阶段,每个成矿阶段都发育热液石英。利用LA-ICP-MS原位微区分析技术,对不同成矿阶段石英开展了微量元素组成分析。结果显示,第二阶段为主成矿阶段,矿化最为强烈,是金的主要生成阶段。载金矿物以硫化物为主,但第二阶段Sb、Bi含量显著升高,Au、Ag与Cu、Pb、Zn等金属元素具有正相关关系,说明主成矿阶段的载金矿物可能还有碲化物和铋化物,以微颗粒形式包裹于石英中。基于热液石英Ti含量构建的石英Ti地质温度计显示,热液成矿期成矿温度逐渐降低。石英中Al、Ti、Li含量的规律性变化,表明成矿流体pH逐渐升高,由最初的酸性逐渐向中性、弱碱性演化。
Xicha Gold-Silver Deposit is classified as a mesothermal vein type deposit formed in the Early Cretaceous,primarily containing gold with associated silver.The mineralization process went through both a hydrothermal mineralization period and a supergene mineralization period,with the hydrothermal mineralization period divided into 3 stages,each characterized by the development of hydrothermal quartz.Using LA-ICP-MS in-situ micro-zone analysis techniques,micro element composition analysis of quartz at different mineralization stages was conducted.The results indicate that the second stage is the main mineralization stage with the strongest mineralization,serving as the primary gold mineralization phase.Gold-bearing minerals are predominantly sulfides,but during the second stage,the content of Sb and Bi significantly increases,and gold and silver show a positive correlation with other metallic elements such as copper,lead and zinc,suggesting that the gold-bearing minerals in the main mineralization stage may also include telluride and bismuthide,or be encapsulated in quartz in the form of fine particles.The quartz Ti geothermometer constructed based on the titanium content in hydrothermal quartz indicates a gradual decrease in mineralization temperature during the hydrothermal mineralization period.The systematic changes in Al,Ti,and Li content in quartz suggest a gradual increase in fluid pH from initial acidity towards neutral to weak alkalinity.
作者
马敏霞
孙凌云
孙金磊
赵昌吉
钱烨
Ma Minxia;Sun Lingyun;Sun Jinlei;Zhao Changji;Qian Ye(Qianjiang Real Estate Registration Center;School of Earth Sciences,Jilin University;Institute of Geochemistry,Chinese Academy of Sciences;Shandong Province Engineering Research Center for Deep Gold Mine Detection Big Data Application Development)
出处
《黄金》
CAS
2024年第6期65-76,共12页
Gold
基金
吉林省自然科学基金项目(20220101161JC,20170101201JC)
深部金矿探测大数据应用开发山东省研究中心开放课题(SDK202203)。
