祁漫塔格那东矽卡岩型铀矿化特征及成矿作用

Character of Skarn Type Uranium Mineralization And Metalization in Nadong,Qimantage Area

那东矽卡岩型铀矿化产于祁漫塔格多金属成矿带内。通过岩、矿石光薄片鉴定和电子探针分析显示,该类型铀矿化的赋存岩石主要由透辉石、石榴子石、方柱石、硅灰石、钠长石等矿物组成,矿石矿物主要为沥青铀矿和磁铁矿,其他矿物有石英、斜长石、黑云母、方解石、独居石、褐帘石和萤石等。铀除了以沥青铀矿形式存在外,部分以类质同像赋存于独居石、褐帘石、硅钍石、方钍石中,少量以吸附形式出现。沥青铀矿有粒状和裂隙充填的脉状两种形态。矿化特征和成矿作用分析表明,该类型铀矿化在成因上与矽卡岩化作用相关,具有铁、铀共生成矿的特点。

Nadong skarn type uranium mineral izat ion is located in the polymantage. Based on microscopic examination and EPMA analysis, it. was found that, u ran ium m in e ra l iz a -tion was hosted in rocks composed by uraninite magnetite galena pyrite. The principal gangue minerals are mainly plagioclase, qua r tz, biot.ite, calcite an d so on. T h e ma in u ran ium m in e ra l is u r a n in i te, th erest, of uranium to be found occurs through isomorphism or adsorption in changbaiite, it.e,and thorianite. The uraninite have two kinds of existence form , g ra n u la r an d f issure. T h e m in e ra i i-zation is related to skarmization by the characteristics of uranium and iron symbiosis. Uranium mineraii- zation time between quartz sulfide stage and carbonate stage of iron metallogenic period.