江西相山矿田典型铀矿床流体包裹体特征及意义

Fluid inclusion characteristics of typical uranium deposits in Xiangshan orefield,Jiangxi Province

对江西相山铀矿田3个典型铀矿床邹家山、横涧和沙洲矿床铀矿石中的萤石矿物进行了系统流体包裹体研究。结果表明,邹家山矿床-130 m标高和206 m标高流体包裹体的均一温度平均值为266.1℃和159.9℃,盐度w（NaCleq）为11.61%和13.16%,密度为0.88 g/cm3和1.00 g/cm3;均一温度与盐度之间呈抛物线型关系,密度与均一温度为负相关,而密度与盐度正相关。横涧矿床-3 m标高和92 m标高流体包裹体的均一温度平均值为259.9℃和291.7℃,盐度w（NaCleq）为13.45%和7.95%,密度为0.91 g/cm3和0.79 g/cm3;均一温度与盐度正相关,密度与均一温度负相关、与盐度关系不明显。沙洲矿床-138 m标高和-98 m标高流体包裹体的均一温度平均值为297.3℃和272.9℃,盐度w（NaCleq）为13.73%和11.62%,密度为0.86 g/cm3和0.87 g/cm3;均一温度与盐度之间规律性不明显,密度与均一温度负相关、与盐度之间关系不明显。计算获得邹家山矿床-130 m标高和206 m标高铀成矿平均深度是860 m和550 m,横涧矿床-3 m标高和92 m标高平均深度是930 m和950 m,沙洲矿床-138 m标高和-98 m标高平均深度为578 m和537 m。与地表标高对比获得,邹家山、沙洲和横涧铀矿床形成后的剥蚀程度分别在320~416 m、190~240 m、727~902 m之间。相山北西部地区的抬升剥蚀程度强于南东部地区,显示东部和南部地区在深部有较好的找矿前景。

Based on a study of the fluid inclusions in fluorite from the Zoujianshan,Hengjian and Shazhou uranium deposits in the Xiangshan uranium orefield of Jiangxi,the authors have drawn the conclusions as follows： In the Zoujiashan uranium deposit,the average homogenization temperatures of fluid inclusions are 266.1℃ and 159.9℃ at the elevations of-130 m and 206 m,the average salinities w（NaCleq） are 11.61% and 13.16%,and the mean densities of fluorite inclusions are 0.88 g/cm3 and 1.00 g/cm3,suggesting that the regularity of homogenization temperature and salinity is of the parabola type;the density and homogenization temperature are significantly of negative correlation,and the density and salinity are of positive correlation.In the Hengjian uranium deposit,the average homogenization temperatures of fluid inclusions at the elevations of-3 m and 92 m are 259.9℃ and 291.7℃ respectively,the average salinities w（NaCleq） are 13.45% and 7.95%,and the mean densities are 0.91 g/cm3 and 0.79 g/cm3.The density and homogenization temperature are obviously of negative correlation,and the density and salinity do not show obvious correlation.In the Shazhou uranium deposit,the average homogenization temperatures of fluid inclusions are 297.3℃ and 272.9℃ at the elevations of-138 m and-98 m,the average salinities w（NaCleq） are 13.73% and 11.62%,and the mean densities of fluorite inclusions are 0.86 g/cm3 and 0.87 g/cm3,suggesting that the regularity of homogenization temperature and salinity is inconspicuous,the density and homogenization temperature are significantly of negative correlation,and the relationship between density and salinity is not obvious.In the Zoujiashan ore deposit,the average uranium metallogenic depths at the elevations of-130 m and 206 m are 860 m and 550 m,measured by the fluid inclusion method.In the Hengjian ore deposit,the average uranium metallogenic depths at the elevations of-3 m and 92 m are 930 m and 950 m.In the Shazhou ore deposit,the average uranium metallogenic depths at the elevations of-138 m and-98 m are 578 m and 537 m.A comparison with the surface elevation shows that the denudation depths after the formation of the Zoujiashan,Hengjian and Shazhou uranium deposits are respectively 320~416 m,190~240 m,and 727~902 m.The extent of uplift and erosion in northwestern Xiangshan is more serious than that in southeastern Xiangshan area,and the deep areas of eastern and southern Xiangshan have favorable ore-search prospect.