CSAMT方法在松辽盆地西南部白音花凹陷铀矿勘查中的应用

CSAMT法是一种使用人工场源、通过改变发射频率进行测深的地球物理方法。该方法以勘探深度大、分辨能力强、抗干扰能力强等特点成为研究深部地质特征的有效手段。白音花凹陷位于松辽盆地西南部,针对研究区第四系覆盖厚度较大(100 m)、人文干扰较多、要求勘探深度较深(1000 m)等特点,在该研究区采用可控源音频大地电磁测量方法进行测量。通过可控源音频大地电磁测量方法确定研究区的二级构造单元的边界、基底的起伏形态、断裂空间展布形态及砂体的发育情况,从而研究该地区铀成矿地质环境。根据可控源音频大地电磁测量结果,结合地质资料和岩石电阻率资料,经过综合分析认为:可控源音频大地电磁测深法可以划分研究区的二级构造单元、推测断裂的空间展布形态以及确定砂体、泥岩的顶板埋深及厚度,是研究铀成矿地质环境的有效技术手段,对于铀矿勘查工作的进一步开展具有重要意义。该方法在铀矿勘查攻深找盲中起到非常积极的作用,同时也为寻找同类铀成矿地质环境提供指导和借鉴意义。

Application of CSAMT method to the study on uranium prospecting in Baiyinhua sag, southwest of Songliao basin

Controlled-source audio-frequency magnetotelluric is a kind of geophysical methods that are using artificial field to detect the different resistivitiy on different depths by changing the transmitting frequencies. This method has become an effective means to study the deep geological features, with the characteristics of great depth exploration, high resolution and strong Anti-interference ability. Baiyinhua sag is located in the southwest of Songliao basin, Because of the characteristics of Quaternary large thickness (> 100m), more human interference and demand for greater depth of exploration in the study area, the controlled source audio frequency magnetotelluric method is used in this area. We use CSAMT method to confirm secondary tectonic unit boundary, the rolling topography of basement, the space shape of fractures and the development of sand body, Thus studying uranium metallogenic geological environment in this area. Based on geological data and rock resistivity as well as CSAMT data, Through comprehensive analysis shows:The controlled source audio magnetotelluric method can be used to divide secondary tectonic units, detect space shape of fractures and determine the depth and thickness of the top plate of sand body and mudstone in the study area. It is an effective technical method for studying uranium metallogenic geological environment. It has great significance for further development of uranium deposits exploration. This method plays a very active role in exploring deep uranium deposits, at the same time, it also provides guidance and reference for the exploration of similar uranium metallogenic geological environment.