金川铜镍(铂)硫化物矿床岩浆通道成矿系统:来自矿物学的证据  

Magmatic conduit metallogenic system of Jinchuan Cu-Ni(PGE)sulfide deposit:Evidence from mineralogy

作　　者：刘美玉 苏尚国[2] 刘心然 郭旭东 李一鸣 LIU Meiyu;SU Shangguo;LIU Xinran;GUO Xudong;LI Yiming(Disaster Reduction Center of China,Beijing 100124,China;School of Geosciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]应急管理部国家减灾中心,北京100124 [2]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《地学前缘》2025年第2期390-411,共22页Earth Science Frontiers

基　　金：国家自然科学基金委员会重大研究计划项目(92162213)。

摘　　要：金川岩浆铜镍硫化物矿床是世界第三大岩浆型铜镍(铂)硫化物矿床,近年来,关于金川矿床成因机制的讨论一直存在争议。目前流行的成矿模型主要有以下两种:(1)岩浆通道堆积模型;(2)深部熔离多次贯入模型。目前,二者均不能较好解释矿区中存在的各种地质现象,特别是高密度硫化物矿浆上侵难等关键问题。实验岩石学和动力学模拟的最新研究进展表明流体的加入可有效推动高密度硫化物的迁移。前期研究发现,金川矿床硫化物矿石中广泛发育原生富Cl或富C的含水矿物(磷灰石、方解石、金云母、角闪石等),富Cl和C流体活动显著伴随金川矿床成矿过程,而这种富Cl和C流体的加入是否为促使高密度硫化物“矿浆”上侵运移的主要机制还需进一步探讨。针对上述问题,本次研究通过对金川矿床中几类重要矿物进行综合的矿物学、地球化学、同位素地球化学研究,以矿物成因探讨了影响金川矿床高密度硫化物“矿浆”上侵运移的主要机制。金川矿床中的原生含水矿物与金属硫化物构成流体晶矿物组合,由流体晶矿物组合的空间展布规律与岩浆通道的前进方向推测,该富Cl和C的流体由最初的富钙逐渐向富镁、富硅演化。The Jinchuan deposit is the third largest magmatic copper-nickel sulfide deposit in the world.There are still a lot of controversies about its metallogenic mechanism and there are two main models:①Magmatic conduit accumulation metallogenic model and②Deep segregation-injection metallogenenic model.However,none of them can explain the geological phenomena in the mining area well,especially the key problems such as the emplacement of high density sulfide melts.The new progress in experimental petrology and dynamics simulation shows that fluid addition can effectively promote the migration of high-dense sulfide slurry and it might be the main mechanism of emplacement of sulfide melts in the Jinchuan deposit.Previous research found that primary Cl-rich hydrated minerals(phlogopite,amphibole,apatite and calcite)are widely distributed in the Jinchuan sulfide ore,indicating that the formation process of the Jinchuan deposit might be significantly influenced by Cl-and C-rich fluids.This paper focuses on the characteristics of specific hydrous minerals in the deposit to discuss the migration mode and emplacement ability of sulfide meltIn order to investigate the significant effects of this Cl-rich and C-rich fluid on migration of the high-density sulfide melts.The primary hydrous minerals and sulfides in the Jinchuan deposit constitute fluid minerals assemblage.It is speculated that the Cl-and C-rich fluid gradually evolved from calcium-rich to magnesium and silicon-rich according to the spatial distribution of the fluid minerals and the moving direction of the magma conduit.

关 键 词：金川Cu-Ni(PGE)硫化物矿床 磷灰石 流体晶矿物组合 富Cl流体 岩浆通道成矿系统 

分 类 号：P618.41[天文地球—矿床学] P618.63[天文地球—地质学] P611.11P613