纳米比亚罗辛地区矿化白岗岩铀矿物学研究及意义OA北大核心CSTPCD

Objectives:The Rossing deposit is a world-class alaskite-type uranium deposit,with multiple mineralization zones such as SJ,SH,SK,Z17,and Z19.There are significant differences in mineral combinations among these zones,but the level of systematic mineralogical research is not high. Methods:This work systematically studied the symbiotic combination and occurrence status of uranium minerals in the main ore(mineralization)zones of the Rossing area through methods such as rock—mineral determination,scanning electron microscopy observation,and electron probe analysis. Results:The results show that the mineralization of alaskite mineralization can be divided into three categories based on mineral assemblages:① uraninite+zircon+apatite combination,mainly distributed in the Z17,Z19,and SJ areas;② coffinite,uranothorite+sphene+apatite combination,mainly found in the SH area;③ betafite combination,mainly distributed in the SK and SH areas. Conclusions:The uranium mineralization in the study area can be divided into three stages:magmatic stage,hydrothermal stage,and epigenetic leaching stage.The magmatic stage is the primary ore-forming stage,the electron probe chemical age of uraninite in the study area is 505±11 Ma,representing the magmatic mineralization age.In the SH area,further exploration should focus on finding coffinite,uranothorite+sphene+apatite combination in mineralized alaskite.