广西佛子冲铅锌矿床硫化物矿物学特征及其成矿指示意义  

Mineralogical characteristics of sulphide and mineralization implications from the Fozichong Pb-Zn deposit in Guangxi

作　　者：李晓婷 付伟[1,2] 柴明春 滕建清 杨启军[1] 雷良奇[1,2] LI Xiao-ting;FU Wei;CHAI Ming-chun;TENG Jian-qing;YANG Qi-jun;LEI Liang-qi(Guangxi non-ferrous metal deposits and materials development cooperation and innovation center,Guilin university of technology,Guilin,Guangxi,541004;Key laboratory for exploration of concealed metal minerals in Guangxi,Guilin university of technology,Guilin,Guangxi,541004)

机构地区：[1]桂林理工大学广西有色金属隐伏矿床及材料开发协同创新中心,广西桂林541004 [2]桂林理工大学广西隐伏金属矿产勘查重点实验室,广西桂林541004

出　　处：《桂林理工大学学报》2018年第4期663-673,共11页Journal of Guilin University of Technology

基　　金：国家自然科学基金项目(41272394);广西自然科学基金项目(2014GXNSFAA118304);广西高校优秀中青年骨干教师培养工程项目

摘　　要：分析了广西佛子冲大型铅锌多金属矿床(古益和河三矿区)中硫化物矿石的矿相学和矿物化学特征,利用硫化物矿物化学中记录的成矿作用信息探讨矿床的成矿环境和成因类型。古益矿区发育有3个成矿阶段的硫化物组合:早成矿阶段的磁黄铁矿+闪锌矿+方铅矿+黄铜矿+黄铁矿组合;中期成矿阶段的闪锌矿+方铅矿+黄铜矿+黄铁矿组合;晚成矿阶段的黄铁矿+方铅矿+闪锌矿组合。而在相邻的河三矿区,硫化物的成矿阶段相对单一,主要为方铅矿+闪锌矿+黄铜矿+黄铁矿组合。研究表明:(1)在佛子冲矿床的硫化物中,磁黄铁矿的Fe原子百分数为46. 09%～48. 00%,闪锌矿的Zn/Cd值为58. 91～134. 51、Ga/In值为0. 23～1. 00、w(Fe)为1. 98%～12. 52%,这些信息综合指示了佛子冲矿床的成矿环境温度经历了从中高温(280～400℃)到中低温(150～300℃)的演化;(2)黄铁矿中S/Fe为1. 84～1. 99和Co/Ni≥1,闪锌矿中伴生微量元素的具多样性(含Fe、Mn、In、Ga、Ge等)、Zn/Fe(平均9. 96)、Zn/Mn(平均404. 73)和Zn/Cd(平均79. 94)值,方铅矿中Ag、Ga、Ge、In含量整体偏高、Pb/Ag值(平均514. 23)等信息,综合指示了佛子冲矿床硫化物的发育与岩浆热液成矿作用具有密切的成因联系,佛子冲矿床是一个岩浆热液型铅锌多金属矿床。The mineralography and mineral chemistry of some sulphide samples from the Fozichong Pb-Zn polymetallic deposit(Guyi and Hesan districts)and their implications to the deposit genesis were analyzed and discussed.There are three types of sulphide assemblages in the Guyi ore district,including the assemblage of pyrrhotite,sphalerite,galena,chalcopyrite and pyrite in the early mineralization stage,the assemblage of sphalerite,galena,chalcopyrite and pyrite in the middle mineralization stage,and the assemblage of galena,sphalerite and pyrite in the late mineralization stage.The sulphide assemblage in Hesan district is relative simple and characterized by the coexisting of galena,sphalerite,chalcopyrite and pyrite,which approximately corresponds to the middle mineralization stage of the Guyi ore district.Our work reveals that:(1)The atomic percentage of Fe in pyrrhotite is 46.09%-48.00%.The ratio of Zn/Cd,Ga/In and the content of Fe in sphalerite of the Fozichong deposit are 58.91-134.51,0.23-1.00 and 1.98%-12.52%respectively.These information indicates that the ore-forming temperature may have changed from the high-middle temperature(280-400℃)to low-middle temperature(150-300℃)during the mineralization.(2)The ratio of S/Fe is 1.84-1.99,Co/Ni≥1 in pyrite.The associated trace elements in sphalerite show great diversity(including Fe,Mn,In,Ga,Ge,etc.)and the mean values of Zn/Fe,Zn/Mn,Zn/Cd in sphalerite are 9.96,404.73 and 79.94,respectively.In galena,the content of Ag,Ga,Ge,is generally high and the mean value of Pb/Ag is 514.23.These information suggests that the sulphide mineralization was closely related to magma-derived hydrothermal activity,and the Fozichong Pb-Zn polymetallic deposit is a typical magmatic hydrothermal type.

关 键 词：硫化物 矿物化学 矿床成因 铅锌矿床 佛子冲 

分 类 号：P618.4[天文地球—矿床学]