综合物探方法在上杭盆地古石背地区铀矿勘查中的应用

The application of comprehensive geophysical method to the exploration of uranium deposits in the paleo-Shibei area of Shanghang Basin

古石背地区具有良好的铀成矿地质背景,发现了一些矿化点和铀异常,前人工作主要集中在矿化点的周围和浅部,对研究区整体成矿环境的评价和深部成矿条件的认识不足。本文简要介绍了土壤氡、地面伽马能谱和音频大地电磁测量的工作方法,通过综合物探测量对研究区铀成矿环境进行了分析,通过开展土壤氡、地面伽马能谱测量工作,圈定了铀矿异常位于地表的大致位置,通过开展音频大地电磁测量(AMT)查明了控矿断裂古石背断裂和控矿岩层石帽山群的发育特征,推断解释结果得到了钻探验证,为该类型的铀矿勘查工作提供了参考。

The paleo-Shibei area has a good geological background of uranium mineralization,and some mineralization spots and uranium anomalies have been found.The previous work was mainly focused on the surrounding and shallow parts of the mineralization spots,and the evaluation of the overall metallogenic environment and the understanding of the deep metallogenic conditions in the study area were insufficient.The authors briefly introduced the working methods of soil radon,ground gamma energy spectrum and audio frequency magnetotelluric survey,analyzed the uranium metallogenic environment in the study area by comprehensive geophysical survey,delineated the approximate position of uranium ore anomaly on the surface by carrying out soil radon and ground gamma energy spectrum survey,and found the paleo-rock back of ore-controlling fault by carrying out audio frequency magnetotelluric survey(AMT).The characteristics of the development of the fault and ore-controlling strata of Shimaoshan Group were determined,and the inferred interpretation data were verified by drilling,which provides a reference for the exploration of this type of uranium deposits.