南岭地区两种类型盆地的压实流体系统及其矿化作用

TWO KINDS OF COMPACTION FLUID SYSTEMS OF THE NANLING AREAAND THEIR MINERALIZATIONS

盆地构造演化—流体系统—矿化作用是矿床学研究的前缘课题。盆地演化的特征直接影响盆地沉积建造的结构特征。建造结构和地球化学特征对压实流体系统的温度场、动力场、地球化学场和矿化作用产生决定性的影响。滇东南白牛厂早古生代盆地是典型的裂谷式凹陷盆地,上万米厚的黑色页岩与上部碳酸盐岩和砂岩组合有利于矿化的压实流体系统的形成,形成了白牛厂式超大型银多金属矿床。粤北晚古生代盆地为地台型浅海盆地,沉积物主要由透水性较好的粗碎屑物质和碳酸盐岩组成,沉积建造厚度较薄。数字模拟结果表明,粤北盆地压实流体系统难以形成较高的地热储和流体势,流体只能在沉积层的特殊部位汇聚并形成红岩型低温黄铁矿矿床。

Basin's tectonic evolution-fluid system-mineralization is a new frontier of ore deposits .The characteristic of basin's evolution affects the structure of the sedimentary formation directly.Structures of the formations and the character of geochemistry played a crucial role in the forming of thermal field of compaction fluid system,dynamic field and geochemical field and mineralization. Yuebei Late Paleozoic sedimentary basin was mainly made up of coarse clastics with high permeability,and the thicknesses of carbonate and the sedimentary formation were thin.Numerical simulation demonstrated that basin's compaction fluid system cann't form upper terrestrial heat store and upper fluid potentials,the ore-bearing fluid can only be stored in special parts of the sedimentrary layers to form Hongyan low temperature pyrite deposit.Bainiuchang Early Paleozoic sedimentary basin is a typical rift.The fluid from several thousands of meters of black shale and its upper carbonate and sandstone formations constituted compaction fluid system which concentrated the metallogenic elements and formed the Bainiuchang super-large silver-polymetallic deposit.