华南花岗岩型铀矿成矿作用及成矿预测

Metallogenic Process and Prediction of Granite-related Uranium Deposits in South China

华南是我国花岗岩型铀矿主要产地。通过对华南地区不同类型花岗岩型铀矿区域地质背景、成矿作用特征、铀成矿机理以及控矿因素的综合分析,认为华南不同类型花岗岩型铀矿床成矿作用具有相似性,铀成矿具有多期、多阶段特征,成矿物质铀主要来自富铀基底和花岗岩,成矿流体具有壳源和幔源流体成分。花岗岩型铀矿属于深源地幔流体和大气降水共同参与的复成因成矿作用的产物,断裂构造是最关键的控矿因素,受控于中新生代岩石圈伸展作用。在此基础上,构建了华南地区区域铀成矿模式和预测评价模型,预测了重点地区富大铀矿成矿远景区4片,基于GOCAD软件开展了书楼丘、鹿井、沙子江矿床三维地质模型构建和深部铀成矿预测,实现了“定型、定位、定深、定量”预测,为华南地区下一步铀矿找矿工作部署提供了科学依据。

South China hosts numerous granite-related uranium deposits.Based on the comprehensive study on the regional geological background,metallogenic characteristics,uranium metallogenic mechanism and ore-controlling factors of different types of granite-related uranium deposits in South China,it is concluded that the metallogenic processes of these uranium deposits have many similarities.Uranium mineralization is characterized by multiple stages.Uranium is mainly derived from uranium-rich basements and granitoids,and the ore fluids have crust-derived and mantle-derived components.Both deep mantle-derived fluids and meteoric water play important roles in the formation of granite-related uranium deposits controlled by Mesozoic–Cenozoic lithospheric extension.The fault is the most critical ore-controlling factor.Therefore,the regional uranium metallogenic models and prediction models in South China were established.Four uranium metallogenic prospective areas were predicted.Based on the GOCAD software,deep uranium metallogenic potential were predicted,and the three-dimensional geological models were established of Shulouqiu,Lujing and Shazijiang deposits.The positioning,quantifying,classifying,and depth-determining prediction of uranium resources were realized,which provides suggestions for the further deployment of uranium ore exploration work in South China.