摘要
湖南省的金矿95％为含金石英脉型,几乎全部产于前寒武系。容矿构造主要为古老的东西向压扭性断裂,部分为华夏系的北东向断裂。矿床一般均远离火成岩体,少数矿床(点)局部可见含金锑石英脉切割燕山期酸性岩脉。与成矿有关的方铅矿、黄铁矿的铅同位素模式年龄及有关地质地球化学特征表明:金的成矿主要形成于武陵-雪峰期(10～6.0亿年)和加里东期(6.0～3.4亿年),而印支-燕山期(2.3～0.7亿年)则产生局部的热液叠加。多次构造运动为成矿作用提供有利空间和热源,从而促使金的活化转移并沉淀成矿。
The number of gold deposits in Hunan province consist of 95% gold-bearing quartz veins almost occurring in Precambrian succession. Hoststructures are mainly older EW-trending compresso-shear fractures, par-tially Cathaysian NE-striking fractures. Ore Deposits are located gene-rally far from igneous mass and in a few of ore deposits (occurrences)Yanshanian acidic dikes are intersected locally by Au-and Sb-bearingquartz veins. According to chronology of Pb isotope and geochemistry oforeforming galena and pyrite, it is confirmed that gold mineralizationwasformed during the Wuling-Xuefengian cycle (1000～600m. y.) and theCaledonian cycle(600～340m. y.), whereas partial superimposition by hy-drothermal solutions took place during the Indo-China-Yanshanian cycle(230～70m. y.). Multi-cyclic tectonism. provided favourable spaces andheat sources for mineralizations, resulting in the mobilization anddeposition of gold and the formation of the gold deposits.
关键词
金矿床
成矿时代
前寒武系
湖南
gold deposit
Precambrian system
metallogenic epoch
Pb isotope
Hunan
