Generally, audio frequency magnetotelluric sounding (AMT) and controlled source audio frequency magnetotelluric sounding (CSAMT) are used for deep exploration. The AMT method has a relatively wide acquisition frequency band, but is affected by weak signals in certain frequency bands of the natural field, which is called "dead band". In the "dead band" range, the geological body response cannot be obtained completely. However, CSAMT has the characteristics of high signal-to-noise ratio due to the introduction of artificial source; therefore, due to the limitation of transmitting power, the distance between transmitting and receiving is generally not far enough, so it is easy to enter the "near area" prematurely. This paper proposes a processing method that combines the two methods of data splicing. Firstly, on the basis of previous theoretical research, the forward calculation is carried out by using CSAMT and AMT uniform half space model, and the results show that the combination of CSAMT and AMT data is feasible. Secondly, the field measured data of No. 7 geological section of the Renli niobium and tantalum deposit in Hunan Province are tested by using the CSAMT far area data and the AMT data at the same measuring point with the same mode to "splice". Finally, the new AMT data derived from synthesization are used. The results show that the inversion results and the drilling results correspond well, which proves that the method has good promotion significance.
刘俊峰, 程云涛, 邓志强, 周芳春, 曹创华, 刘翔, 曾美强, 李杰, 黄志彪, 陈虎. CSAMT与AMT数据“拼接”处理——以湖南仁里铌钽矿床7号剖面为例[J]. 物探与化探, 2021, 45(1): 68-75.
LIU Jun-Feng, CHEN Yun-Tao, DENG Zhi-Qiang, ZHOU Fang-Chun, CAO Chuang-Hua, LIU Xiang, ZENG Mei-Qiang, LI Jie, HUANG Zhi-Biao, CHEN Hu. CSAMT and AMT data "splicing" processing: A case study of No.7 profile of the Renli niobium tantalum deposit in Hunan Province. Geophysical and Geochemical Exploration, 2021, 45(1): 68-75.
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