黔东南金矿与圈定的黔湘桂新元古代火山构造特征及地质意义

Features of Gold Deposits in the Southeastern Guizhou and the Neoproterozoic Volcanic Structures in the Qian-Xiang-Gui Adjacent Region and the Geological Significance

黔东南金矿地质勘查及找矿研究程度低,为之利用区域重磁资料,研究深部成矿环境,圈定区内可能存在一处大型的中心式喷发火山环形构造或隐伏岩浆岩体分布群。岩体异常北东向分布,覆盖面积广,组合形态复杂,分带特征明显,跨越黔湘桂三省区,主体异常在贵州,部分在湖南和广西,并受控于3条深大断裂,见中心环带、内环带、过渡环带、外环带,4带发育齐全,火山岩相配套出现,岩体异常分枝发育。研究发现天柱—锦屏—黎平及丹寨—三都与湘西会同—怀化等地区金矿,极有规律地分布于相应构造环带和地表背斜区及有利赋矿地层内,由内环向外环依次出现石英脉型、蚀变岩型、微细粒浸染型金矿。所圈定的潜火山构造或隐伏岩体群,将对黔湘桂交界地区地质特征及金矿成矿规律产生新的认识,具有重要的地质意义。

The degree of the geological survey for gold deposits in the southeastern Guizhou and the mineral ex- ploration study are very low, so the deep metallogenic environment is studied by using regional gravity and mag- netic data, and a central eruption volcano circular structure or a group of concealed magmatic rocks are delinea- ted there. The abnormal rock masses are distributed in the north-east direction and have a widely coverage area with complex configuration forms and obvious zoning characteristics. The abnormal rock masses cross the Qian- Xiang-Gui adjacent region and the principal anomaly is distributed in Guizhou. The distribution of the rock mas- ses is controlled by three deep fractures, and four annules completely develop, i.e. center annule, inner annule, transitive annnle and outer annule. The lithic facies appear with a whole set, and the branched rock ab- normalities develop well. It is also found that gold deposits in Tianzhu-Jinping-Liping are similar with those in Danzhai-Sandu and Huitong-Huaihua and are regularly distributed along the structure band surface anticline or in the ore-rich formation, appearing quartz-vein, alterated-rock and microgranular-disseminated type gold de- posits. This study has an important geological significance for a new understanding on geological characteristics and ore-forming regularity of gold deposits in the Qian-Xiang-Gui adjacent region.