贵州西部峨眉山玄武岩区金矿赋矿层位及矿石特征——以盘县架底金矿为例  

The Ore-Bearing Horizon and Ore Characteristics of Gold Deposits in the Emeishan Basalt Area of Western Guizhou:A Case Study of the Jiadi Gold Deposit in Panxian County

作　　者：张兵强 杨清毫 赵富远 谭礼金 肖成刚[1] 王石华[1] 李俊海[1] 马建 谢智 熊伟[1] ZHANG Bingqiang;YANG Qinghao;ZHAO Fuyuan;TAN Lijin;XIAO Chenggang;WANG Shihua;LI Junhai;MA Jian;XIE Zhi;XIONG Wei(No.105 Geological Team,Guizhou Bureau of Geology and Mineral Exploration and Development,Guiyang,Guizhou 550018)

机构地区：[1]贵州省地质矿产勘查开发局一0五地质大队,贵州贵阳550018

出　　处：《地质与勘探》2020年第6期1145-1157,共13页Geology and Exploration

基　　金：贵州省地质矿产勘查开发局地质科研项目(编号:黔地矿科合(2017)12号);贵州省地质矿产勘查开发局地质科研项目(编号:黔地矿科合(2017)10号);贵州省地质矿产勘查开发局地质科研项目(编号:黔地矿科合(2016)12号);贵州省科技计划项目(编号:黔科合平台(2018)5765号)联合资助。

摘　　要：架底金矿是贵州省乃至全国在玄武岩地层中发现的最大原生金矿床,是近年来贵州西部寻找金矿的一个重要突破。为了加强对该类金矿床的研究,通过对矿区赋矿层位及围岩系统的岩石学、矿物学对比分析,总结出空间上,矿区金矿体可划分为上下两层,两层金矿体分别赋存在上下两个含矿体中。上含矿体为峨眉山玄武岩组第二段中部的一套以火山角砾岩(约占95%)为主,岩石具有一定破碎和蚀变的特殊岩层;下含矿体是中二叠统茅口组与上二叠统峨眉山玄武岩组的不整合界面附近,在区域构造和热液蚀变的综合作用下形成的一套构造蚀变体。两层金矿体容矿岩石主要为玄武质火山角砾岩、凝灰岩,占总量的90%以上,其次为少量的玄武质火山砾岩、浅灰色玄武岩及灰岩角砾。矿区各类围岩蚀变发育,与金矿成矿关系最密切的蚀变有硅化、黄铁矿化、白云石化。硫化物为金的主要载体,金为偏光显微镜下难以分辨的显微金、次显微金及晶格金。The Jiadi gold deposit is the largest primary gold deposit discovered in the basalt formations of Guizhou Province and even the whole country,representing an important breakthrough in the gold ore-search in western Guizhou in recent years.In order to improve the research of this kind of gold deposit,this work conducted comparatve analysis of surrounding rock system and ore horizon.It is found that,in space,the gold ore body in the mining area is divided into upper and lower layers,hosted in the upper and lower two ore-bearing bodies,respectively.The upper ore-bearing body is a set of volcanic breccia(about 95%)in the middle part of the second section of the Emeishan basalt,in which the rock has a certain fracture and alteration.The lower ore body is a set of structural altered rock mass formed by the unconformity interface between the Middle Permian Maokou Formation and the Upper Permian Emeishan basalt formation under the combined influence of regional structure and hydrothermal alteration.The two-layer gold ore body is mainly composed of basaltic volcanic breccia and tuff,accounting for more than 90%of the total,followed by a small amount of basaltic volcanic conglomerate,light gray basalt and limestone breccia.All kinds of surrounding rock alterations in the mining area are well developed,and the alterations most closely related with gold deposits are silicification,pyrite mineralization and dolomitization.Sulfide is the main gold-hosting mineral,and gold is indistinguishable microscopic gold,submicroscopic gold and lattice-gold under polarizing microscope.

关 键 词：玄武岩 火山角砾岩 赋矿层位 矿石特征 架底金矿 盘县 贵州 

分 类 号：P618[天文地球—矿床学]