河北金厂峪金矿床辉钼矿与金矿化关系研究及意义  

Relationship between Molybdenite and Gold Mineralization in Jinchangyu Gold Deposit,Hebei Province and Its Significance

作　　者：孙豪 宋扬[1] 李超[2] 郑明 孙鹏程 方颖 SUN Hao;SONG Yang;LI Chao;ZHENG Ming;SUN Peng-cheng;FANG Ying(MNR Key Laboratory of Metallogeny and Mineral Resource Assessment,Institute of Mineral Resources,Chinese Academy of Geosciences,Beijing 100037;National Research Center for Geoanalysis,Beijing 100037;School of Earth Sciences and Resources,China University of Geosciences(Beijing)Beijing 100083)

机构地区：[1]中国地质科学院矿产资源研究所,自然资源部成矿作用与资源评价重点实验室,北京100037 [2]国家地质实验测试中心,北京100037 [3]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《地球学报》2022年第2期157-171,I0001,172,共17页Acta Geoscientica Sinica

基　　金：国家重点研发计划项目(编号:2018YFC0604106);自然资源部杰出青年人才项目(编号:KY-BR-XZ-202006)联合资助。

摘　　要：辉钼矿Re-Os测年方法现已广泛应用于各类金属硫化物矿床成矿年代学研究领域,已成为石英脉型金矿床实现直接、准确定年的重要手段。然而,正确理解辉钼矿与金成矿作用之间的确切关系,选取具有代表性的辉钼矿样品是测年的前提。本文聚焦冀东地区规模最大的金矿床——金厂峪金矿床,对其石英-钠长石-多金属硫化物脉中的黄铁矿和辉钼矿两者的产出状态及原位微量元素特征进行了详尽的对比,研究探讨了金厂峪金矿床中辉钼矿与金矿化之间的关系。研究发现石英-钠长石-多金属硫化物脉含金丰富,可见金和不可见金均大量赋存,黄铁矿和辉钼矿均为重要的载金硫化物。镜下矿相学及原位微量元素证据表明,早期形成的含金黄铁矿经历了再活化过程,为稍晚形成的富金辉钼矿提供了大量的Au源,两者可能为同一大的金成矿事件下不同成矿流体脉冲事件的产物。辉钼矿形成于金厂峪金矿的主成矿阶段,与Au的二次浓集紧密相关,并可作为高品位金矿体的标志性矿物之一。本文认为在准确厘定辉钼矿与金矿化关系的基础上,辉钼矿Re-Os方法是一种可靠的石英脉型金矿直接定年手段。Re-Os dating of molybdenite is a direct and accurate means to date quartz vein-type gold deposits using the model age or isochron approach.However,to correctly identify the exact relationship between molybdenite and gold mineralization,representative molybdenite samples should be selected for dating.In this study,we focused on the largest gold deposit in eastern Hebei Province—Jinchangyu gold deposit—and compared the microscopic structure and in-situ trace element characteristics of molybdenite and auriferous pyrite from quartz-albite-polymetallic sulfide vein.Quartz-albite-polymetallic sulfide veins were found to contain significant amounts of visible gold and invisible gold;both pyrite and molybdenite are known as important gold-bearing sulfides.Based on detailed mineralogical work,we suggest that the early gold-bearing pyrite experienced a remobilization process,which acts as an important source of Au for gold-rich molybdenite.Further,the two may be products of different ore-forming fluid pulse periods under the same large-scale gold mineralization event.Molybdenite was formed in the main metallogenic stage of the Jinchangyu gold deposit,which is closely related to the secondary concentration of Au and may be used as one of the symbolic minerals to identify high-grade gold ore bodies.Based on the accurate determination of the relationship between molybdenite and gold mineralization,the molybdenite Re-Os chronometer is a reliable direct dating method for identifying quartz vein-type gold deposits.

关 键 词：辉钼矿 原位微量元素 RE-OS定年 石英脉型金矿 金厂峪 冀东 

分 类 号：P618.51[天文地球—矿床学] P618.65[天文地球—地质学]