纳米比亚欢乐谷地区白岗岩型铀矿床流体包裹体特征及成矿作用

文章对纳米比亚欢乐谷地区白岗岩型铀矿床流体包裹体的温度、盐度、密度和成分等进行了系统的分析研究,厘定了成矿流体的类型及基本性质,并对该地区铀成矿的物理化学条件和成矿流体来源进行了初步探讨。研究表明,该地区白岗岩型铀矿床的成矿流体可分为2个期次:主成矿期和叠加改造期。主成矿期的流体为岩浆晚期的残余高温、低盐度热液,其气相成分主要是CO2,含少量H2O、N2和CH4;叠加改造期的流体为中-低温、低盐度热液,其气相成分以CO2和H2O为主,含少量CH4和N2,来源于岩浆期后热液与大气水的混合。

Fluid inclusions and metallogenesis of alaskite-type uranium deposits in Gaudeanmus area, Namibia

On the basis of field survey and a comparative study of petrography, microthermometry and Laser Raman ingredients of fluid inclusions, the authors investigated the basic characteristics (temperature, salinity, density, ingredients, etc.) of fluid inclusions of alaskite-type uranium deposits in the Gaudeanmus area, Namibia and, on such a basis, discussed the physical and chemical conditions of mineralization and the sources of ore-forming fluids. The results indicate that the ore-forming fluids of alaskite-type uranium deposits in the study area can be divided into two stages: main mineralization stage and reformation stage. The fluid of the main mineralization stage is characterized by magnatic residual high temperature and low salinity, and the vapor ingredient of this fluid is mainly CO₂, containing a small amount of H₂O, N₂ and CH₄, whereas the fluid of the reformation stage was derived from meteoric water, mixed with a little magmatic water, with the vapor ingredient being mainly CO₂ and H₂O together with a small amount of CH₄, N₂.