南秦岭柞水−山阳矿集区金盆梁金矿床载金硫化物矿物学特征及成矿指示  

Mineralogical Characteristics and Metallogenic Indication of Gold−Bearing Sulfides in the Jinpenliang Gold Deposit, Zhashui−Shanyang Ore Cluster Area, South Qinling

作　　者：葛战林 顾雪祥[2,3] 章永梅[2,3] 郑艳荣 刘明 郝迪 王元伟 GE Zhanlin;GU Xuexiang;ZHANG Yongmei;ZHENG Yanrong;LIU Ming;HAO Di;WANG Yuanwei(Xi’an Center of Mineral Resources Survey,China Geological Survey,Xi’an 710100,Shaanxi,China;School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China;State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Beijing 100083,China)

机构地区：[1]中国地质调查局西安矿产资源调查中心,陕西西安710100 [2]中国地质大学(北京)地球科学与资源学院,北京100083 [3]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083

出　　处：《西北地质》2023年第5期278-293,共16页Northwestern Geology

基　　金：国家自然科学基金重点项目“新疆西天山北缘晚古生代斑岩−矽卡岩型铜钼铁多金属成矿与岩浆−热液作用过程”(42130804);中国地质调查局项目“东秦岭高岭沟−五里川一带锑金矿产调查评价”(ZD20220306);陕西省自然科学基础研究计划资助项目(2023-JC-QN-0284)联合资助。

摘　　要：金盆梁金矿床位于南秦岭柞水−山阳金多金属矿集区北部,矿体呈近东西向赋存于上泥盆统桐峪寺组的沉积建造中,受左行韧性断层控制。关于矿石矿物学与金成矿过程尚缺乏系统的认识。基于岩矿相学鉴定、背散射电子图像(BSE)、能谱(EDS)及电子探针分析(EPMA)等方法,查明矿石组构与载金硫化物毒砂、黄铁矿、辉锑矿及白铁矿的矿物学特征,探讨金的赋存状态与成矿物理化学条件,初步厘定矿床成因类型。结果显示,热液成矿期的金矿化以微细浸染型为主,可划分为黄铁矿−毒砂−硅化(Ⅰ)、石英−辉锑矿−白铁矿±锑氧化物(Ⅱ)及方解石−石英(Ⅲ)3个阶段。不同载金硫化物的“不可见金”赋存状态差异显著,由毒砂的晶格金Au+,到早世代黄铁矿(Py-1)的晶格金Au+−纳米金Au0,至晚世代黄铁矿(Py-2)和白铁矿的纳米金Au0。金属矿物组合由毒砂−黄铁矿至辉锑矿−白铁矿,成矿流体由较高温的相对自然金不饱和状态,逐渐演化为相对低温的自然金饱和状态。金盆梁金矿床形成于较高硫逸度的中高温、中浅成环境,属于卡林型金矿床。The Jinpenliang gold deposit is located in the northern part of the Zhashui−Shanyang ore cluster area,South Qinling.The E−W trending main orebodies,occurring in sedimentary rocks of the Upper Devonian Tongyusi Formation, are strictly controlled by the left−lateral ductile faults. To date, there is still insufficient un-derstanding of the ore mineralogy and gold mineralization processes. In this paper, we obtain data from a vari-ety of experimental methods, such as petrographic identification, Back−Scattered Electron imaging (BSE), Ener-gy Dispersive Spectrometry (EDS), and Electron Probe Micro−Analysis (EPMA), to determine the mineralogi-cal characteristics of gold−bearing sulfides (arsenopyrite, pyrite, stibnite, and marcasite), and discuss the chemi-cal states of Au and physicochemical conditions for gold mineralization. The results show that the micro−dis-seminated gold mineralization in hydrothermal period can be divided into three stages: pyrite−arsenopyrite−sili-cification stage (Ⅰ), quartz−stibnite−marcasite±antimony oxides stage (Ⅱ), and calcite−quartz stage (Ⅲ). The occurrence states of “ invisible gold” vary greatly among different gold−bearing sulfides, from Au+ in ar-senopyrite to Au+ and Au0 in early generation pyrite (Py-1), then to Au0 in late generation pyrite (Py-2) and mar-casite. The metal mineral assemblage changes from arsenopyrite−pyrite to stibnite−marcasite, while the ore−forming fluid gradually evolves from relatively high−temperature solutions unsaturated with respect to na-tive gold to low−temperature solutions saturated with respect to native gold. The Jinpenliang gold deposit is a Carlin−type gold deposit, which was formed in a medium−high temperature and shallow−moderate depth with logf(S2) ranging from −8.5 to −4.5.

关 键 词：金的赋存状态 毒砂地质温度计 电子探针 载金硫化物 金盆梁 南秦岭 

分 类 号：P575.1[天文地球—矿物学] P618.51[天文地球—地质学]