海南西部戈枕金矿成矿带的矿床类型及成因

海南西部戈枕断裂为区域性控矿构造，沿该断裂的旁侧近等距分布的一系列金矿床，构成戈枕金矿成矿带，根据其成矿地质特征、控矿因素等可划分为3种矿床类型，即蚀变糜棱岩型、蚀变碎裂岩型和石英脉型．研究表明，成矿物质具多源性，赋矿层位戈枕村组的原岩为来自上地幔的火山岩，有初始的矿源，该组金丰度高，为矿源层，成矿过程中混合岩化作用、岩脉蚀变等都补充了金质；硫源来自矿源层原始硫，成矿与混合岩化热液有关；成矿在中温、弱酸-弱碱性环境，成矿作用多期、多阶段，成矿时代为晚古生代-早中生代，矿床属混合岩化热液成因．

Types and Genesis of Gezhen Gold Deposit Metallogenic Belt in the Western Area of Hainan

Gezhen fracture located in the western area of Hainan is a regional ore control structure, Gezhen gold mine metallogenic belt is formed by a series of gold deposits allocated along the side of this fracture. Three types of deposits could be classified based on their geologic features and metallotects. The three gold deposits are alterational mylonite rocks, alterational cataclastic rocks and type of quartz vein. Researches prove the polytopism of the deposits formation.The initial rocks in the Gezhencun formation is rich with gold mine because the volcanic rocks rise from upper mantle which contains the initial source of the deposits.The Gezhencun formation contains abundant gold mines. It is the source bed accumulated during the ore-forming processes of migmatization and vein alteration.Sulphur is originated from ore source bed,with the thermal fluid of the migmatization. Ore deposits are formed in the settings of the mesothermal temperature and in the states of the subacidity and alkalescency. Metallogenesis characterized by the polyphase and multistage,metallogenetic epoch might be neopaleozoic or Mesozoic Era.Genesis of mineral deposit might be the thermal fluid in the migmatization.