粤东桃源铀矿床流体包裹体特征研究

Characteristics of Fluid Inclusions in Taoyuan Uranium Deposit in Eastern Guangdong

桃源矿床是位于长塘火山盆地西侧中型热液铀矿床,其铀成矿与萤石化关系非常密切。在详细的野外和显微镜观察基础上,运用显微测温和激光拉曼测试手段对桃源矿床萤石中的流体包裹体开展研究。结果表明:桃源铀矿床流体包裹体主要为气液两相盐水溶液包裹体,均一温度为138.6~267.2℃,均值为202.2℃,属中低温范围;包裹体盐度w(NaCl_(eqv))为6.24%~14.51%,均值为11.52%,属中低盐度范畴;密度为0.87~1.00 g/cm^(3),均值为0.95 g/cm^(3);包裹体均一温度与盐度呈一定的负相关性,密度与均一温度呈明显的负相关性,密度与盐度呈正相关性。根据包裹体温度和盐度估算出成矿深度为0.79~1.53 km,平均值为1.14 km,属于中等深度成矿环境。

The Taoyuan deposit is located on the west side of the Changtang volcanic basin,and it belongs to a medium-sized hydrothermal uranium deposit.Uranium mineralization is closely related to fluorite formation.Based on detailed field investigation and microscope observation,research is conducted on fluid inclusions in fluorite from the Taoyuan deposit.The results show that the fluid inclusions in the Taoyuan deposit are mainly gas-liquid two-phase salt solution inclusions.The homogenization temperature is from 138.6 to 267.2℃with the average of 202.2℃,suggesting that these minerals were formed at medium-low mineralization temperature.The salinity w(NaCl_(eqv))is from 6.24%to 14.51%with the average of 11.52%,which belongs to medium-low salinitie.The density of inclusions is from 0.87 to 1.00 g/cm^(3) with the average of 0.95 g/cm^(3).The homogenization temperature and salinity are significantly of negative correlation,but the density and homogenization temperature are significantly of negative correlation,and the density and salinity are significantly of positive correlation.According to the temperature and salinity of the inclusions,the mineralization depth is estimated from 0.79 to 1.53 km with the average of 1.14 km,which belongs to a medium-depth mineralization environment.