陕西光石沟铀矿床铀赋存状态和铀成矿期次研究

Uranium Occurence State and Uranium Metallogenic Periods of Guangshigou Uranium Deposit,Shaanxi Province

采用矿石薄片鉴定、矿物参数自动分析系统检测、电子探针分析对光石沟铀矿床铀的赋存状态进行研究。结果表明,光石沟铀矿床铀矿物主要为晶质铀矿,铀石、钍石、钍铀矿、含铀独居石含量很低。晶质铀矿主要呈稀疏浸染状分布在脉石矿物粒间,与钾长石连生密切,其次与黑云母连生,常见锆石和石英包体。铀石主要与方解石、黄铁矿(白铁矿)连生,组成细小环边断续分布于部分晶质铀矿周边。钍铀矿、钍石呈包裹体赋存于独居石中,独居石呈星散状分布于脉石矿物中。根据铀矿物的赋存状态,光石沟铀矿床成矿期可划分为岩浆期和热液期两个成矿期次,其中岩浆期的矿物组合为晶质铀矿、钾长石和黑云母,热液期的矿物组合为铀石、方解石和黄铁矿(白铁矿)。

The uranium occurrence of Guangshigou uranium deposit was studied by ore thin section identification,automatic analysis system detection of mineral parameters and electron probe analysis.The results show that uranium mineral of Guangshigou uranium deposit are mainly uraninite.Coffinite,thorite,thoruraninite and uranium monazite content is very low.Uraninite is closely associated with K-feldspar,mainly distributed among gangue mineral as a sparse disseminated manner,and followed by biotite.Azorite and quartz inclusions are commonly observed in it.Uranite is mainly associated with calcite and pyrite(marcasite),which occured as tiny rim intermittently distributed in part of uraninite periphery.Broggerite and thorite occured as inclusions in monazite.Monazite is scattered in gangue minerals.According to the occurrence of uraninite minerals,Guangshigou uranium deposit can be divided into magmatic and hydrothermal metallogenic period.The mineral association in magmatic period are uraninite,K-feldspar and biotite.The mineral association in hydrothermal period are cofinite,calcite and pyrite(marcasite).