黔东早寒武世早期重晶石富集机制研究——来自硫同位素的约束  

A Study of the Enrichment Mechanism of Early Cambrian Barite in Eastern Guizhou:Constraint from Sulfur Isotope

作　　者：王富良[1,2] 黄艺 付勇 龙克树[1] 文星桥[5] WANG Fu-liang;HUANG Yi;FU Yong;LONG Ke-shu;WEN Xing-qiao(College of Resources and Environmental Engineering,Guizhou University,Guiyang,Guizhou 550025;Guizhou Geological Environment Monitoring Institute,Guiyang,Guizhou 550081;Bureau of Reserve and Transaction of Mineral Right,Guizhou Province,Guiyang,Guizhou 550004;Key Laboratory of Karst Georesources and Environment,Ministry of Education,Guiyang,Guizhou 550025;No.101 Geological Party,Bureau of Geology and Mineral Exploration and Development of Guizhou Province,Kaili,Guizhou 556000)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州省地质环境监测院,贵州贵阳550081 [3]贵州省矿权储备交易局,贵州贵阳550004 [4]喀斯特地质资源与环境教育部重点实验室,贵州贵阳550025 [5]贵州省地质矿产勘查开发局101地质大队,贵州凯里556000

出　　处：《地球学报》2020年第5期686-698,共13页Acta Geoscientica Sinica

基　　金：国家自然科学基金委-贵州省联合基金项目(编号:U1812402);国家自然科学基金项目(编号:41763006)联合资助。

摘　　要：在中国,早寒武世早期重晶石矿床主要展布于扬子地台北缘秦岭—大巴山一带及扬子地台东南缘湘黔地区,而黔东天柱大河边重晶石矿床已探明的资源储量就达到了2亿多吨,是全国,乃至世界上罕见的超大型重晶石矿床。近年来,于大河边重晶石矿床北西翼亦发现了赋存于同一层位的云洞重晶石矿床,但二者的成矿特征却表现出显著的差异。本文对比了含矿较差的云洞重晶石矿床与高品位大河边重晶石矿床的含矿岩系、沉积相、地球化学特征等。结果表明两者之间的缺氧程度、热水作用强度存在明显差异。综合矿床地质和有机质、硫同位素特征,提出成矿作用与生物活动和同期海底热液活动关系密切,矿床中SO4^2-来源于海水硫酸盐,Ba^2+来自海水和海底热液。大河边地区与云洞地区相比,水位更浅,氧逸度更高,硫酸盐还原程度更弱,剩余硫酸盐的浓度更高,从而导致云洞重晶石矿床表现出较大河边重晶石矿床成矿性差的特征。The barite deposits formed in Early Cambrian are mainly distributed in the north(Qinling-Dabashan area)and southeast(Hunan-Guizhou border area)margin of the Yangtze platform in China.Distributed in the east of Guizhou Province,the barite deposits of Dahebian and Tianzhu have reached more than 200 million tons,which constitute a rare superlarge barite orefield both in China and in the world.The Yundong barite deposit in the same horizon has also been found in the northwest wing of the Dahebian barite deposit in recent years,but there are significant differences between them in metallogenic characteristics.In this paper,the authors compared the Yundong barite deposit with the Dahebian barite deposit by the correlation work of ore-bearing rock series,sedimentary facies and geochemical characteristics.The results show that the difference of ore-bearing potential is affected by the degree of hypoxia and the intensity of hot water action.Based on the characteristics of organic matter and sulfur isotopes,this paper discusses the metallogenic mechanism of barite deposits in Tianzhu area.SO4^2- in the deposit was derived from seawater sulfate and Ba^2+ came from seawater and submarine hydrothermal solution.Compared with the Yundong barite deposit,the Dahebian barite deposit is characterized by shallower water level,higher oxygen fugacity,weaker sulfate reduction and higher residual sulfate concentration.As a result,the Yundong barite deposit shows the characteristics of poor metallogeny compared with the Dabian barite deposit.

关 键 词：贵州 天柱 重晶石 控矿因素 硫同位素 

分 类 号：P597.2[天文地球—地球化学]