广西龙胜大地金矿枫木坪矿段矿床地质特征及金的赋存状态  

Geological characteristics and gold occurrence state of Fengmuping oreblock in Dadi gold deposit,Longsheng County of Guangxi

作　　者：魏翔宇 赵延朋 刘耀辉 卢见昆 潘剑云 黎家财 傅啊耀 陈晓锋 莫江平 WEI Xiangyu;ZHAO Yanpeng;LIU Yaohui;LU Jiankun;PAN Jianyun;LI Jiacai;FU A'yao;CHEN Xiaofeng;MO Jiangping(China Nonferrous Metals(Guilin)Geology and Mining Co.,Ltd.,Guilin 541004,Guangxi,China;Longsheng County Dexin Mining Co.,Ltd.,Longsheng 541700,Guangxi,China)

机构地区：[1]中国有色桂林矿产地质研究院有限公司,广西桂林541004 [2]龙胜县德鑫矿业有限公司,广西龙胜541700

出　　处：《矿产与地质》2023年第4期697-706,共10页Mineral Resources and Geology

基　　金：中国有色桂林矿产地质研究院有限公司科技创新基金项目(KDYCXJJ202103);中色桂林院创新基金(KDY2019003)共同资助。

摘　　要：基于大量钻井岩心、薄片、电子探针和扫描电镜资料,对枫木坪矿段矿石特征、矿体特征、成矿阶段划分和含金黄铁矿成分等研究,探讨枫木坪矿段矿床地质特征和金的赋存状态,以期为后续勘探、选冶和矿床成因研究提供基础信息。研究表明:枫木坪矿体陡倾斜脉状产出,严格受构造控制;矿体平面上呈“中间厚大、两侧较薄”,纵向上呈“上厚下薄”的特征。矿石金属矿物有黄铁矿、褐铁矿、毒砂和少量金、黄铜矿和方铅矿等;脉石矿物有石英、方解石、绿泥石、云母等。金的赋存形式主要有可见金和不可见金2种形式。可见金呈不规则粒状、片状赋存于石英、黄铁矿和毒砂中,形成包体金、晶隙金和粒间金等;不可见金多富集于含砷黄铁矿中部环带,金赋存方式有纳米级自然金和固溶体金。枫木坪矿段不可见金富集主要与As^(-)取代S^(-)进入黄铁矿有关,黄铁矿晶格发生扭曲和位错,形成空位和缺陷,易于Au^(+)富集。黄铁矿成分指示矿床成矿物质可能主要来源于桂北浅变质岩系的围岩地层。Based on a large number of drilling holes,thin sections,electron probe and scanning electron microscopy data,the ore characteristics,ore body characteristics,mineralization stage division,and gold-bearing pyrite composition of Fengmuping ore segment are studied and the geological characteristics of the deposit and the occurrence state of gold in the Fengmuping ore segment are discussed in order to provide the basic information for subsequent exploration,ore selection and smelting and deposit genesis research.The research result shows that the Fengmuping ore body is steeply inclined and veined,which is strictly controlled by the structure.The ore body is characterized by'thick in the middle and thin on both sides'on the plane,and'thick in the upper and thin in the lower'in the longitudinal direction.The ore metal minerals include pyrite,limonite,arsenopyrite and a small amount of gold,chalcopyrite and galenite.Gangue minerals include quartz,calcite,chlorite,mica,etc.The occurrence forms of gold are mainly visible gold and invisible gold.It can be seen that gold is irregularly granular and flaked in quartz,pyrite and arsenopyrite in the form of inclusion gold,crystal gap gold and intergranular gold.The invisible gold is mostly enriched in the middle zone of arsenic-bearing pyrite,and the occurrence mode of gold is nano-scale natural gold and solid solution gold.The invisible gold enrichment in the Fengmuping oreblock is mainly related to the As^(-)substituted S^(-)entering pyrite.The pyrite lattice is distorted and dislocated,and Au^(+)is enriched in vacancies and defects in the lattice.The composition of pyrite indicates that the ore-forming materials of the deposit might mainly come from the surrounding rock strata of the shallow metamorphic rock series in North Guangxi.

关 键 词：金矿 黄铁矿 金赋存状态 黄铁矿成因 广西龙胜 

分 类 号：P618.51[天文地球—矿床学]