Application of pseudo-random frequency domain electromagnetic method in mining areas with strong interferences
(1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, Central South University, Changsha 410083, China;
2. Hunan Key Laboratory of Nonferrous and Geological Hazard Detection, Control South University, Changsha 410083, China;
3. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
4. Research Institute No. 230, CNNC, Changsha 410011, China)
2. Hunan Key Laboratory of Nonferrous and Geological Hazard Detection, Control South University, Changsha 410083, China;
3. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
4. Research Institute No. 230, CNNC, Changsha 410011, China)
Abstract: Due to the strong electromagnetic interferences and human interference, traditional electromagnetic methods cannot obtain high quality resistivity data of mineral deposits in Chinese mines. The wide field electromagnetic method (WFEM), in which the pseudo-random signal is taken as the transmitter source, can extract high quality resistivity data in areas with sever interference by only measuring the electric field component. We use the WFEM to extract the resistivity information of the Dongguashan mine in southeast China. Compared with the audio magnetotelluric (AMT) method, and the controlled source audio-frequency magnetotelluric (CSAMT) method, the WFEM can obtain data with higher quality and simpler operations. The inversion results indicate that the WFEM can accurately identify the location of the main ore-body, which can be used for deep mine exploration in areas with strong interference.
Key words: pseudo-random signal; frequency domain electromagnetic method; wide field electromagnetic method (WFEM); strong interference; anti-interference capability; Dongguashan copper deposit