ON THE EPOCH OF THE FORMATION OF PRECAMBRIAN GOLD DEPOSITS IN HUNAN PROVINCE
Luo Xianlin Guilin College of Geology
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.