铜陵矿集区块状硫化物矿床地质特征

Geological Characteristics of Massive Sulfide Deposits in Tongling Ore Concentration Area, Anhui Province

蚀变_流体填图揭示 ,铜陵地区石炭系黄龙组喷流沉积含矿岩系中普遍存在块状硫化物矿床 ,上部为层状块状硫化物矿层 ,下部为浸染状、细脉_网脉状硫化物矿体 ,具有典型的双层结构。自下而上矿石具有垂直分带性 :硅质矿石、石膏矿石、黄铁矿矿石、黄铁矿_重晶石矿石和菱铁矿_铁质燧石矿石。矿石发育胶状和莓球结构 ,微细层纹状_马尾丝构造。矿石成分以黄铁矿和菱铁矿为主。矿床发育一套独特的热液气爆角砾岩不规则网脉和相互连通的虫管状_树枝状_姜块状黄铁矿管道系统 ,矿化形式为弥散式多喷口席状矿化 ,厚度一般不超过 10 0m。

The alteration and fluid mapping show that pyrite_type massive sulfide deposits widely occur within Carboniferous sedimentary_exhalative ore_bearing rocks of the Huanglong Formation. The deposit, characterized by a representative two_layer texture, consists of the exhalation phase massive stratiform ore bed in the upper part and the feeder channelway phase disseminated_stockwork orebody in the lower part. It has distinct vertical metallic zoning in the upward order of siliceous, gypsum, pyrite, pyrite_barite and siderite_siliceous ores. Colloform, framboidal textures and laminated, brecciated structures of exhalation are widely developed in the stratiform ores. Ores are dominated by pyrite and siderite. The deposit shows a well_developed characteristic exhalation pipeline system, which includes irregular stockworks of hydrothermal explosion breccia, breccia pipes and interconnected worm_pipes, and branch_like and ginger_like pyrite pipes. The dispersed multi_spout sheets or blanket_like alteration and mineralization zones are distributed regionally and the massive mineralization occurs locally. As a role, the sheet alteration and mineralization zones do not exceed 100 m in thickness.