湘西金-锑-钨矿深部矿化初步预测  

PRELIMINARY PREDICTION OF MINERALIZATION AT THE DEPTH OF XIANGXI Au Sb W ORE DEPOSIT

作　　者：杨思学[1] 张振儒[2] 张哲儒[3] 

机构地区：[1]柏林自由大学地质系,德国柏林12207 [2]中南工业大学地质系,长沙410083 [3]中国科学院地球化学研究所,贵阳550002

出　　处：《矿物学报》1999年第4期435-445,共11页Acta Mineralogica Sinica

摘　　要：湘西金 -锑 -钨矿产于晚元古代紫红色板岩——马底驿组。该组以富含 Fe2 O3 ,局部富含 Ca O为特征 ,可能作为地球化学障控制着本区矿床及矿化的分布。湘西金矿中主要控矿要素为 :构造、地层及主要成矿元素络合物的地球化学性质。金以 Au(HS) -2 形式搬运 ,其沉淀主要由紫红色板岩的氧化作用而形成的黄铁矿化引起。钨以 WO-4 和 HWO4 形式存在 ,温度的降低及局部富钙围岩的存在控制着其沉淀。锑不仅以 Sb(OH) 03 ,而且以 Sb S-2 和 Hn Sb Sn-24 (n=0 ,1或 2 )的形式存在 ,其沉淀成矿主要由温度的降低所控制。预测在— 510 m标高及其以下 ,只要有紫红色板岩存在 ,在构造有利处 ,金矿化将继续存在 ,而钨、锑矿化将会逐渐尖灭。The Xiangxi Au Sb W ore deposit——the largest in NW Hunan, China——occurs in red slate of the Late Proterozoic Madiyi Formation,characterized by high contents of Fe 2O 3 and locally of CaO relative to other formations. The major controlling ore factors are:structure,the Mediyi Formation, and the geochemistry of complexes of major ore forming elements.The Madiyi Formation perhaps as a geochemical barrier controls the deposits or mineralizations in NW Hunan and also the Xiangxi deposit.Gold in the Xiangxi deposit may primarily be transported in the form of Au(HS) 2 that can rapidly be precipitated by pyritization of the red slate——the Madiyi Formation.Tungsten occurs mainly as complexes:HWO - 4 and WO 2- 4 in the solution. The deposition of these two complexes depends on the CaO content in the host rock and the dropping of ore forming temperature.Antimony can exist not only in the form of Sb(OH) 0 3,but also as SbS - 2 or H n SbS ( n-2) 4(n =0,1,or 2) in the solution.Their solubility is strongly influenced by dropping temperature. Therefore, at the depth of -510m there may be still gold mineralization,when the Madiyi Formation exists and there is also favourable structural condition while the mineralization of tungsten and antimony may disappear.

关 键 词：金-锑-钨矿 共生矿 矿化 金矿床 

分 类 号：P618.510.5[天文地球—矿床学] P578[天文地球—地质学]