贵州镇宁泥盆系大型重晶石矿床地球化学特征及其成因研究  

Geochemical Characteristics and Genesis of Large Devonian Barite Deposits in Zhenning County,Guizhou Province

作　　者：高军波[1] 杨瑞东[1] 陶平 魏怀瑞[1] 刘坤[1] 程伟[1] 

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550003 [2]贵州省地质调查院,贵州贵阳550004

出　　处：《现代地质》2013年第1期46-55,共10页Geoscience

基　　金：教育部博士点基金项目(20105201110002);贵州省地质矿产勘查开发局2009年度重大科研项目"水城-紫云-南丹晚古生代裂陷作用及其与主要矿产的关系";贵州省长基金;贵州大学博士点学科建设基金项目

摘　　要：水城—紫云—南丹深断裂是跨越黔桂两省较为闻名的断裂带,沿断裂带两侧分布一系列矿床类型,贵州镇宁泥盆系大型重晶石矿床位于北西侧。对镇宁大型重晶石矿床的沉积学、地球化学及成矿背景的研究发现,矿石中发育纹层状构造、条带状构造、角砾状构造、碎屑状构造和厚层块状构造等热水沉积构造,常量元素特征揭示该矿床可能形成于以SiO2及含矿硫酸盐流体的同生混合沉积作用。重晶石矿(岩)石中Sr、Zn和W明显富集,显示热水沉积特征,且该重晶石矿(岩)石在lg U-lg Th和Cr-Zr相关图解上也均显示热水沉积特征。稀土配分模式富集轻稀土,δEu表现正异常,δCe表现负异常,具热水喷流成矿特征。因此,认为镇宁大型重晶石矿属海底热水喷流沉积形成的产物。Shuicheng-Ziyun-Nandan deep fault is a well-known belt expanding across two provinces （ Guizhou and Guangxi）, along both sides distributing a series of diverse deposit types, and the large Devonian barite de- posit is an important ore deposit in Zhenning County, Guizhou. The large barite deposit, located in the north- west margin of Shuieheng-Ziyun-Nandan deep fault was studied on the basis of the sedimentation characteristics, geochemistry and metallogenic background. The results revealed coexistence of a variety of hydrothermal water sedimentary structures characteristics such as laminar structures, barite-banded structure, breeciated structure, barite-fragmental structure, massive structure, and so on. Macroelement study indicated that the deposit was formed probably by synsedimentation of SiO2 and ore-bearing sulfate fluid. Besides, geochemistry of the large barite deposits of the Devonian shows the enrichment of St, Zn and W, strongly suggesting that the barite depo- sits is hydrothermal sedimentation in origin. The diagrams of tgU-lgTh and Cr-Zr in the barite deposit also pres- ent the features of hydrothermal sedimentation. According to the REE distribution pattern, LREE were enriched and Eu was positive while Ce was negative, which also shows a hydrothermal feature. As a result, we believed that the large barite deposits located in Zhenning formed by hydrothermal exhalative mineralization.

关 键 词：热水喷流 地球化学 重晶石矿床 泥盆系 贵州 

分 类 号：P619.2[天文地球—矿床学]