贵州东部石英脉型金矿地质特征和成矿作用

Geological Characteristics and Mineralization of Quartz-vein-type Gold Deposits in East of Guizhou

贵州东部以晚元古代地层为容矿地层的金矿,主要是石英脉型金矿。它们主要分布在从江地区、天柱—锦屏—黎平地区和梵净山地区。前2者处于南华褶皱带西缘,后者处于南华褶皱带与扬子陆块的过渡带。矿体分布在断裂(带)和背斜核部。共伴生矿物为石英、黄铁矿、毒砂、闪锌矿、方铅矿、黝铜矿,黄铜矿,辉锑矿、绿泥石等。矿化蚀变以硅化、黄铁矿化、毒砂化、绿泥石化为主。形成温度主要集中在100℃～350℃,是中低温热液矿床,呈现100～150℃和200～300℃两个区段。金有来源于围岩的、也有来源于深部岩浆的；流体有来源于地层和深部的,也有大气降水的混入。金矿的形成是多时代多阶段形成的：雪峰期提供原始物质；加里东期是一次主要成矿期；燕山时期也是一个重要的金矿形成时期,不但形成新金矿。

The gold deposits, occurred within the strata of the Upper Proterozoic in the east area of Guzhou, are dominant to quartz - vein type. The majorities are distributed over the Chongjiang, Tianzhu - Jinpin - Liping, and Fanjinshan Mountain areas. The former two lie on the west flank of Nanhua fold belt, the latter one is at transition belt of Nanhua fold zone and Yangtze landmass. Ore bodies range in the fracture zone and anticline core, with accompanying minerals like as quartz, pyrite, arsenopyrite, sphalerite, galena, tetrahedrite, chalcopyrite, antimonite and chlorite. Mineralized alteration gives prior to silicification, pyritization, arsenopyritization and chloritization. The deposits formed in epithermal and mesothermal of temperature chiefly ranging between 100℃ and 350℃, unfolding two segments of 100℃ to 150℃ and 200℃ to 300℃. There exist gold derived from wall rock and also from deep- seated magma; and the fluid derived from beds and deep -seated and from atmosphere precipitation as well. The gold deposits have undergone multi -age and multistage formation ; original supplies are provided during the Xuefeng Stage ; Caledonian Stage is a chief mineralization stage ; Yansanian Stage is also a master gold - forming stage, not only formed new gold deposit and also transformed the gold deposits formed in Caledonian Stage.