The application of CSAMT with small and medium-sized transmit-receive distance to the shallow geological exploration
SHANG Tong-Xiao1,2, GUAN Yi-Xiao1,2, ZHU Shou-Feng1,2, JIANG Guo-Qing1,2, LI Jian-Ping3, LI Xiang-Qian1,2
1. Key Laboratory of Earth Fissures Geological Disaster, Ministry of Land and Resources, Nanjing 210018, China;
2. Geological Survey of Jiangsu Province, Nanjing 210018, China;
3. College of Geological Science & Engineering, Shandong University of Science and Technology, Qingdao 266590, China
Based on analyzing the excitation distribution characteristics of the bipolar source in a homogeneous half-space electromagnetic field and discussing the correlation between the transmit-receive distance and the maximum depth of prospecting, the authors hold that CSAMT characterized by small transmit-receive distance, long bipolar source and short potential electrodes can be applied to geological exploration in the shallow layer of a strong noisy-level environment, and has such merits as high signal-to-noise and uniform distribution of electromagnetic field along the line direction. This paper briefly describes fieldwork and data-processing methods of CSAMT, and illustrates typical experimental curves under man-made interferences, controlled tests on the dipole-dipole resistivity sounding and applied cases in shallow geophysical exploration. The inversion results are similar in controlled tests, but CSAMT has higher resolution and stronger anti-interference capability. Interpretations of applied cases match the drilling verification, indicating that CSAMT with small and medium-sized transmit-receive distance array has practical value and application prospect in the shallow geophysical exploration.
尚通晓, 关艺晓, 朱首峰, 姜国庆, 李建平, 李向前. 中小收发距CSAMT在浅层地球物理勘查中的应用[J]. 物探与化探, 2015, 39(2): 425-431.
SHANG Tong-Xiao, GUAN Yi-Xiao, ZHU Shou-Feng, JIANG Guo-Qing, LI Jian-Ping, LI Xiang-Qian. The application of CSAMT with small and medium-sized transmit-receive distance to the shallow geological exploration. Geophysical and Geochemical Exploration, 2015, 39(2): 425-431.