综合物探方法在陕西富县地区铀矿勘查中的应用

Application of integrated geophysical-geochemical method in uranium deposit in Fuxian,Shaanxi Province

鄂尔多斯盆地南缘黄土覆盖严重,常规地质手段难以实现找矿效果,本文选取盆地南缘富县地区作为研究区,应用航空伽玛能谱测量、活性炭测氡和音频大地电磁测量等物探方法,开展从区域分析到局部验证的综合研究。首先通过分析航空伽玛能谱测量数据,圈定重点找矿地区;其次利用地面活性炭测氡,查明铀矿化异常信息;再次利用音频大地电磁测量,查明其目的层结构特征;最后结合钻探揭露情况,对异常信息进行验证,从而形成了一套航空(重点选区)—地面(查明铀异常信息和成矿环境特征)—地下(钻探验证)综合物探找矿模式,为今后在鄂尔多斯盆地南缘进行砂岩型铀矿勘查提供借鉴。

Because of the serious coverage of loess in southern Ordos Basin,it is difficult to realize the prospecting effect by conventional geological methods. This paper used Integrated geophysical methods including airborne gamma spectrum survey,activated carbon measurement of radon and audio magneto telluric measurements,to conduct comprehensive study from regional analysis to local verification in Fuxian area.First,the prospecting areas were selected by the airborne gamma spectrum data.Then,uranium mineralization anomaly information was extracted by activated carbon measurement. Next,the characteristics of target strata structure and lithology-lithofacies were obtained by using audio magnetotelluric measurements. Finally,the uranium anomaly was verified by drilling work.Thus,a set of integrated prospecting models was constructed,consisting of a set of airborne geophysical survey( selection of key prospecting area)-ground method( identify the characteristics of uranium anomaly and uranium metallogenic conditions)-underground measurement method( drilling verification),which provided the reference for further uranium prospecting in southern Ordos Basin.