贵州威宁昊星铅锌矿地球化学特征及成因浅析  

Geochemical Characteristics and Preliminary Genesis Analysis of the Haoxing Lead-zinc Deposit in Weining,Guizhou

作　　者：安正泽[1] 王佳武[1] 洪万华[1] 张仁彪[1] 郑超[1] 刘健[1] 谢小峰[1] 左勇 尹森林[2] 肖俊岩 闫斌[4] AN Zheng-ze;WANG Jian-wu;HONG Wan-Huan;ZHANG Ren-biao;ZHENG Chao;LIU Jian;XIE Xiao-feng;ZUO Yong;YIN Sen-lin;XIAO Jun-yan;YAN Bin(103 Geological Party,Guizhou Bureau of Geology&Mineral Exploration and Development,Tongren 554300,Guizhou,China;117 Geological Party,Guizhou Bureau of Geology&Mineral Exploration and Development,Guiyang 550000,Guizhou,China;Poly Defence Research Center Co.Ltd,Beijing 100088,China;Institute of geology,Chinese Academy of Geological Sciences,Beijing 100037,China)

机构地区：[1]贵州省地质矿产勘查开发局103地质大队,贵州铜仁554300 [2]贵州省地质矿产勘查开发局117地质大队,贵州贵阳550000 [3]保利国防科技研究中心有限公司,北京100088 [4]中国地质科学院地质研究所,北京100037

出　　处：《贵州地质》2019年第4期342-351,共10页Guizhou Geology

基　　金：贵州省地质矿产勘查开发局重大科研专项(黔西北地区铅锌找矿攻关)资助，编号:黔地矿纪要(2015)14号

摘　　要：昊星铅锌矿床位于黔西北威宁县境内的云炉河坝地区,毗邻川滇黔接壤铅锌矿集区内第二大的毛坪铅锌矿床。该矿床赋存于泥盆系碳酸盐岩中,矿体呈似层状、透镜状及脉状产出,与赋矿地层产状基本一致,受NE向构造控矿明显。硫化物矿石的Pb品位为1.5%42.80%,平均2.89%,Zn品位为1.5%35.92%,平均9.86%。可见,昊星铅锌矿床的成矿特征与会泽、毛坪和天桥等川滇黔铅锌矿集区内的其他典型矿床较相似。昊星铅锌矿床硫化物(黄铁矿、闪锌矿和方铅矿)的δ34 S CDT值介于-57.21‰+3.93‰,则明显不同于会泽、毛坪和天桥等矿床(5‰%25‰),暗示昊星铅锌矿床的还原硫可能具有不同的来源或形成机制。通过分析认为,该矿床的硫很可能是海相硫酸盐生物还原过程(BSR)的产物,而黄铁矿异常低的δ34 S可能是非封闭体系BSR批式分离的结果,即BSR过程形成的还原硫分批随着流体迁移至异地参与成矿。方铅矿的Pb同位素组成显示,昊星铅锌矿床的成矿金属主要由基底岩石提供。因此,本文认为昊星铅锌矿床是流体混合的产物,起源或流经基底岩石的成矿流体与BSR过程形成的还原性流体在异地发生混合,伴生部分TSR和水/岩相互作用过程,赋矿沉积岩中的蒸发岩和金属元素参与到了成矿之中,最终形成昊星铅锌矿床。The Haoxing lead-zinc deposit,located in Yunluheba,Weining County,NW Guizhou Province,is adjacent to the second largest lead-zinc deposit(Maoping)in the Sichuan-Yunnan-Guizhou lead-zinc metallogenic Province.This deposit is hosted in Devonian carbonate rocks,and its orebodies occur as stratiform,lenticular and veined.The occurrence of those ore bodies is basically consistent with that of the ore-bearing strata,and is obviously controlled by the NE structures.The Pb grade of sulfide ore is 1.5%42.80%,with an average of 2.89%,and the ore grade of Zn is 1.5%35.92%,with an average of 9.86%.The ore-forming characteristics of the Haoxing lead-zinc deposit are similar to those of other typical deposits,such as Huize,Maoping and Tianqiaoin the Sichuan-Yunnan-Guizhou province.Theδ34 S CDT values of sulfides(pyrite,sphalerite and galena)in the Haoxing deposit range from-57.21 to 3.93‰,which are obviously different from those of the Huize,Maoping and Tianqiao deposits(5‰25‰),suggesting that the reduction S of the Haoxing lead-zinc deposit may have different origin or formation mechanism.It is considered that Sulfur of the deposit is probably the product of biological reduction of marine sulfate(BSR),while the abnormal depletion of pyriteδ34 S CDT is probably the result of BSR batch separation of the unenclosed system.Hence,the reduction Sulfur batches formed by the BSR process participate in mineralization with the migration of fluids to different places.The Pb isotopic compositions of galena show that the ore-forming metals of the Haoxing lead-zinc deposit are mainly supplied by basement rocks.Therefore,it is considered that the Haoxing lead-zinc deposit is the product of fluid mixing.The ore-forming fluids derived from or flowing through the basement rocks mixed with the fluids of reduced sulfur by BSR in different places,with the association of TSR and water/rock interaction,the evaporites and metal elements in the ore-hosting sedimentary rocks participated in the mineralization and finally formed the Haoxing lea

关 键 词：硫同位素 铅同位素 成矿物质 昊星铅锌矿 黔西北铅锌矿成矿区 

分 类 号：P618.42[天文地球—矿床学] P618.43[天文地球—地质学]