铜陵朝山金矿床矿石特征与金的赋存状态研究

朝山金矿的主要矿石类型为含金硫铁矿石,矿石中富含铋矿物,且作为主要载金矿物,是该矿床的标型特征和重要找矿标志.矿石多呈结晶粒状结构、各种充填-交代结构,块状、浸染状、细脉状构造.金矿物以形态复杂的微粒、细粒自然金、银金矿、金银矿为主,赋存形式有晶隙金、包体金、连生金、裂隙金,载金矿物为石英、自然铋、辉铋矿、磁黄铁矿、黄铁矿、黄铜矿、毒砂等.综合分析认为:该矿床是典型的夕卡岩型独立金矿,成矿流体的不混溶是金富集成矿的主因.

ORE CHARACTERISTICS AND OCCURRENCE OF GOLD MINERALS IN THE CHAOSHAN GOLD DEPOSIT, TONGLING AREA

Studies of both field and ore microscopy indicate that the gold -bearing sulfide ore is major gold ore type in the Chaoshan gold deposit. Bismuth mineral, one of major gold - carrying minerals, has a typomorphic significant and an important clue for prospecting of Chaoshan deposit. Ore textures mainly include crystalline - granular and filling - metasomatic textures with various shapes. Ore structures are dominantly massive, disseminated and veinlet. Fine- grain native gold and electrum occur in the major gold -carrying minerals like quartz, native bismuth, bismuthinite, pyrrhotite, pyrite, chalcopyrite and araenopyrite at the state of interlocking, inter- granular, crevice and enclosure. Characteristics of gold ore bodies, wallrock alteration as well as fluid inclusions indicate that Chaoshan gold deposit is a typical skarn gold - only deposit. Phase separation of ore - forming fluids played an important role in the metallogenetic process.