贵州兴仁滥木厂汞铊矿床黄铁矿LA-ICP-MS微量元素特征与铊成矿  

LA-ICP-MS trace element characteristics of pyrites from the Lanmuchang Hg-Tl deposit in Xingren County, Guizhou Province and the Tl mineralization of the deposit

作　　者：赵凤其 顾尚义[1,2] 毛旗 邓朝霞 郭子栋 ZHAO Feng-qi;GU Shang-yi;MAO Qi;DENG Zhao-xia;GUO Zi-dong(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory of Geological Resources and Environments,Guizhou University,Ministryof Education,Guiyang 550025,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州大学地质资源与环境教育部重点实验室,贵州贵阳550025

出　　处：《矿物学报》2022年第5期692-704,共13页Acta Mineralogica Sinica

基　　金：国家重点研发计划(编号:2018YFC1802601)。

摘　　要：贵州兴仁滥木厂汞铊矿床是世界上首个报道的独立铊矿床,与黔西南卡林型金矿均具有相同的Au-As-Sb-Hg-Tl元素组合,并和水银洞超大型金矿处在同一矿田内。以往研究已经证实富砷黄铁矿是滥木厂汞铊矿床最重要的载铊矿物,而水银洞金矿的含金矿物也主要为黄铁矿。本文通过对滥木厂矿化岩石的岩相学及全岩微量元素分析发现其具有明显的黄铁矿化和辰砂化,13个样品的w(Tl)平均为142×10。在此基础上进一步开展黄铁矿的LA-ICP-MS原位微量元素分析并与水银洞金矿含金黄铁矿对比,探讨二者之间的成因联系以及滥木厂地区铊的富集成矿机制。黄铁矿的LA-ICP-MS结果表明,热液黄铁矿中w(Tl)、w(As)、w(Cu)和w(W)平均分别为888.0×10^(-6)、1992.8×10^(-6)、310.1×10^(-6)和547.7×10^(-6),w(Au)几乎都低于0.1×10^(-6)的检测限,最高仅为0.1×10^(-6)。相比之下,邻区具有相同矿化层位的水银洞金矿中热液黄铁矿显著富集Au、As,而滥木厂汞铊矿床中则以Tl、W的富集为主。结合这2个矿床的矿物组合特征,认为滥木厂铊的富集成矿起源于区内成矿热液在金沉淀后的残余酸性富铊流体,并随着成矿温度的降低与围岩发生广泛的中和反应形成。The Lanmuchang Hg-Tl deposit in Xingren County,Guizhou Province is the firstly reported independent thallium deposit in the world,with the Au-As-Sb-Hg-Tl elemental association similar to that of the Carlin-type gold deposits in the southwestern Guizhou.It is located in the same orefield of the Shuiyindong super-large gold deposit.Previous studies revealed that arsenic-rich pyrite is the most important Tl-bearing mineral in the Lanmuchang Hg-Tl deposit,and the major Au-bearing mineral in the Shuiyindong gold deposit is also pyrite.Petrographic observation and bulk rock trace element analyses of the mineralised rocks from the Lanmuchang in this work show that those mineralised rocks are obviously pyritized and cinnabarized.Their average Tl content of 13 samples is 142 ppm.Further LA-ICP-MS in situ trace element analysis of the pyrite from the Lanmuchang has been carried out and then a comparison between the pyrite from the Lanmuchang deposit and the Au-bearing pyrite from the Shuiyindong gold deposit has been undertaken to investigate the genetic link between the two deposists as well as the enrichment mechanism of Tl in the Lanmuchang area.LA-ICP-MS in situ analytical results show that the average contents of Tl,As,Cu,and W of the hydrothermal pyrite at Lanmuchang are 888.0 ppm,1992.8 ppm,310.1 ppm,and 547.7 ppm,respectively.The Au contents of the pyrites are mostly lower than the detection limit of 0.1 ppm,with the only highest of 0.1 ppm.In comparison,the hydrothermal pyrite within the same mineralization horizons in the neighboring Shuiyindong gold deposit is significantly enriched in Au and As,while the hydrothermal pyrite of the Lanmuchang Hg-Tl deposit is dominantly enriched in Tl and W.Combined with characteristics of mineral assemblages of the two deposits,it is suggested that thallium enrichment and mineralization in the Lanmuchang deposit occurred due to the extensive neutralization reaction between the wallrock and the residual acidic Tl-rich fluid,which was evolved from the original metallogenic hydrot

关 键 词：滥木厂汞铊矿床 黄铁矿 LA-ICP-MS 微量元素特征 成矿流体 

分 类 号：P595[天文地球—地球化学] P611[天文地球—地质学] P618