安徽铜陵矿集区块状硫化物矿床成因模型与成矿流体动力学迁移  

Genetic Model and Dynamic Migration of Ore-forming Fluids in Carboniferous Exhalation-Sedimentary Massive Sulfide Deposits of Tongling District, Anhui Province

作　　者：徐文艺[1] 杨竹森[1] 蒙义峰[1] 曾普胜[1] 史大年[1] 田世洪[1] 李红阳[2] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]石家庄经济学院资源与环境工程系,河北石家庄050031

出　　处：《矿床地质》2004年第3期353-364,共12页Mineral Deposits

基　　金：国家自然科学基金 (编号 40 3 0 3 0 0 8);国土资源部专项研究计划 (编号 2 0 0 10 10 3 0 );国家自然科学基金重点项目 (4 0 2 3 40 5 1)的联合资助

摘　　要：根据地质和同位素地球化学特征 ,建立了铜陵地区赋存于石炭系地层底部的块状硫化物矿床的成因模型 ;该类型矿床的形成主要与石炭纪海底热水活动有关 ,属喷流_沉积型 (SEDEX)块状硫化物矿床 ;下伏古生代地层是重要的成矿金属源区 ,海水硫酸盐是硫化物成矿的主要硫源。成矿热流体循环的动力学数值模拟揭示 ,该类型矿床底盘岩石中的流体活动和热影响范围主要局限在主排泄通道两侧较小的区域内 ;温度场和流场决定以沉积岩为容矿岩石的喷流_沉积型块状硫化物矿床底盘岩石中的蚀变和矿化强度不如以火山岩为容矿岩石的块状硫化物矿床。伴随强大深部热流的张性同生断裂是控制喷流_沉积型块状硫化物矿床形成与分布的关键因素 ,海西期扬子板块北缘的张性构造体制为该时期喷流_沉积型块状硫化物矿床的形成提供了有利的地球动力学环境。Geological evidence and isotopic data reveal that the bedded sulfide deposits hosted in the bottom of the Carboniferous Formation in Tongling district are related to submarine hydrothermal activities and belong to the exhalation_sedimentary massive sulfide type. Seawater provided sulfur and the underlying Paleozoic Formation provided metals for mineralization. On the basis of the above understanding, a genetic model has been established. Numerical simulation of the migration of ore_forming fluids shows that fluid activity and heat_disturbed area in the lying wall rock were confined to a small area around the main draining passage, which led to weak mineralization and alteration in the footwall rock. Due to such factors as temperature and fluid fields, the mineralization and alteration in the footwall rock of exhalation_sedimentary deposits are frequently weaker than those of volcano_hosted massive sulfide deposits. Tensional contemporaneous faults accompanied by strong heat flow control the formation and distribution of the exhalation_sedimentary deposits. Tensional tectonic regime on the northern margin of Yangtze block in Hercynian period provided exhalation_sedimentary deposits with a favorable geodynamic condition.

关 键 词：地球化学 SEDEX型矿床 成因模型 流体动力学 铜陵 

分 类 号：P611[天文地球—矿床学]