可控源音频大地电磁测量在花岗岩型铀矿勘查中的应用

The applications of CSAMT to the exploration of granite type uranium deposits

花岗岩型铀矿床一般产在岩体内部或岩体周边,因此岩体发育情况的探测对铀矿勘查工作的进一步开展具有重要意义。简要介绍了可控源音频大地电磁法在卫境地区的实际应用,结合地质资料和岩石电阻率特征,利用可控源音频大地电磁测量资料,查明了花岗岩体的厚度以及花岗岩和变质岩接触带的深部发育特征,经钻孔验证,效果较好。综合分析认为:可控源音频大地电磁测深法有较好的垂向分辨力,能够较准确探测岩体的厚度、断裂发育的位置及向深部延伸情况、确定破碎带及裂隙带和脉体的空间展布特征,是花岗岩型铀矿勘查的有效技术手段。

The granite type uranium deposit mainly occurs in the interior or at the edge of a rock body. The investigation of the developmental conditions of a rock body thus has significance for uranium deposit exploration. The controlled source audio frequency magnetotelluric（ CSAMT） method and its applications in Weijing area were described in this paper. Based on geological data and rock resistivity as well as CSAMT data,the authors found the thickness of the granite rock mass and the deep development of the contact zone between the granite and the metamorphic rock,and the good results were verified by drilling. A comprehensive analysis shows that CSAMT method has fairly good resolving power in vertical direction. According to results of CSAMT method,the authors detected the thickness of rock bodies as well as the position and the deep characteristics of structures. In addition,the distribution characteristics of the zones of fractures,fissures and vein bodies were detected too. The CSAMT method is an effective means for uranium deposit exploration.