福建福鼎银硐层控铅锌矿床成矿机制探讨

银碉矿区位于浙、闽、粤沿海中生代火山岩分布区中段。富含铅、锌的硅质灰岩为矿源层,对矿床形成提供了相当数量的铅锌。矿石矿物主要是闪锌矿、方铅矿、黄铁矿,伴生少量的黄锕矿、磁黄铁矿、毒砂及辉银矿。脉石矿物主要是石英、石榴石、方解石、绿泥石、硅灰石、透辉石、阳起石及萤石。矿体主要呈层状、似层状或透镜状产于典型地槽复理石建造中,它们严格受中石炭纪硅质灰岩控制。本矿的形成过程,起源于晚古生代冒地槽环境下,由同生沉积作用形成初步富集的含矿层(C_2)。在后期地质事件中,该初始富集的胚胎矿遭受到构造、岩浆及热卤水的作用,活化、转移改造成为现有的工业矿床。

ON THE ORE-FORMING MECHANISM OF THE YINDONG STRATA-BOUND LEAD-ZINC SULFIDE DEPOSIT, FUDING COUNTY, FUJIAN PROVINCE

The Yindong mining district is located in the middle section of mesozoic volcanics along the Zhejiang-Fujian-Guangdong coast. tThe lead-zinc-rich siliceous limestone which Serves as the source bed provides a considerable amount of lead-zinc for the deposit. The ore minerals are chiefly sphalerite, galena, pyrite mixed with a small amount of chalcopyrite, pyrrhotite, arsenopyrite and argentite. The gangue minerals are mainly quartz, garnet, calcite, chlorite, wollastonite, diopside, actinolite and fluorite. The ore bodies which occur in typical geosynclinal flusch formation are mostly stratiform, stratoid, or in lenticular form. They are strictly controlled by siliceous limestone-layers of middle Carboniferous. The process of formation of this deposit originated in latepalaeozoic miogeosyncline enviroment, yielding initial concentration in the ore-bearing horizon(C_2) of syngenetie sedimentation. In the course of posterior geological events, the initially concentrating protore was subjected to tectonism, magmatism, and process of thermal brine and through the modification of mobilization and transportation, formed the present industrial ore deposit.