下庄地区航空放射性钾增高场的地质成因

基于航放数据解译、野外调查和室内研究,分析了粤北下庄地区钾增高场特征,对钾增高场的地质成因开展了初步探讨,为利用钾增高场开展铀成矿区域远景评价奠定了理论基础。研究表明:下庄地区钾增高场主要分布于新桥-下庄断裂带的东侧,具面型展布和跨界(跨越不同期次花岗岩体界线)特征;钾增高场的形成与花岗岩成岩后富钾流体对围岩发生钾质交代作用相关,是水云母化蚀变场的具体反映。指出钾增高场的空间分布范围对下庄地区铀成矿作用的发育及铀矿床产出范围具有重要的指示作用;依据钾增高场可以大致圈定水云母化蚀变场,快速圈出潜在的铀矿找矿远景区(带),有效缩小找矿靶区。

Analysis on characteristics and its geologic origin of potassium increment-field in Xiazhuang area,Northern Guangdong province

Based on the interpretation of airbore radioactivity data,field investigation and the indoor research,this essay analyzed the characteristics of potassium increment-field in Xiazhuang area,preliminary discussed the geologic origin of potassium increment-field.The research proved that potassium increment-field of Xiazhuang area mainly distributes around the east side to the fracture zone of Xinqiao-Xiazhuang,with the characteristics of side-distribution and cross-lithologic bounds;The formation of potassium increment-field was associated with the K-metasomatism of potassic-rich fluid to wall rock after the formation of granite,and the metasomatism was presented by hydromicatization.It was believed that this potassium increment-field played important indicating role in uranium mineralization and uranium deposit formation.According to potassium increment-field,alteration field can be roughly delineated,therefore the prospecting target area can be recognized quickly.