相山铀矿田沙洲矿床流体包裹体研究

对相山铀矿田中的沙洲矿床铀矿石中的萤石矿物进行系统流体包裹体研究。研究结果表明,沙洲铀矿床-138m标高和-98m标高流体包裹体的均一温度平均值分别为297.3℃和272.9℃、盐度平均值分别13.73%和11.62%、密度平均值分别为0.86g/cm3和0.87g/cm3。流体包裹体均一温度与盐度的规律性不甚明显,密度与均一温度成明显的负相关关系,而密度与盐度之间关系不明显。利用流体包裹体方法获得的沙洲矿床-138m标高和-98m标高铀成矿平均深度分别是578m和537m,矿床形成后遭受过较大规模的剥蚀作用,其剥蚀深度大约在190～240m之间。

THE STUDY OF FLUID INCLUSION OF SHAZHOU DEPOSIT IN XIANGSHAN URANIUM ORE-FIELD

Xiangshan uranium ore-field is the biggest volcanic type uranium deposit that has been found in our country.The domestic and foreign geologists have been interested in it for a long time.The homogenization temperature and the melting temperature of ice on fluid inclusions in minerals of fluorite from Shazhou uranium deposits have been measured systematically by microthermometry.We can draw conclusions from this test as follows:Firstly,the average values of homogenization temperature of fluid inclusions is 297.3℃ and 272.9℃ with the average salinity of 13.73wt% and 11.62wt% at the corresponding elevaion of-138m and-98m in the Shazhou uranium deposit,respectively.Secondly,the mean density of fluorite inclusions is 0.86g/cm3 and 0.87g/cm3,which does not show obvious relation between density and formation depth.Thirdly,the regularity of homogenization temperature and salinity is unconspicuous,but the relation of density and homogenization temperature shows significantly negative correlation,and the relation of density and salinity is not obvious.Fourthly,the uranium metallogenic mean depth of-138m and-98m elevation is 578m and 537m,which are equal to their elevations.It thus indicates that the calculated result is reliable.Therefore,we propose that Shazhou uranium deposits have undergone large-scale corrosion.The corresponding corrosive depth is about 190m to 240m.