3D correlation tomography inversion of gravity anomalies constrained by edge features and depth weighting
AN Guo-Qiang1(), LU Bao-Liang1,2,3(), GAO Xin-Yu1, ZHU Wu1,3,4, LI Bo-Sen1
1. School of Geological Engineering and Geomatics, Chang’an University, Xi'an 710054, China 2. National Engineering Research Center of Offshore Oil and Gas Exploration, Beijing 100028, China 3. Key Laboratory of Western Mineral Resources and Geological Engineering, Ministry of Education, Chang'an University, Xi'an 710054, China 4. Key Laboratory of Ecological Geology and Disaster Prevention, Ministry of Natural Resources, Xi'an 710054, China
Correlation tomography is a fast tomography method using correlation coefficients to qualitatively interpret the spatial positions of geobodies. This method, featuring simple, stable, and fast calculations, can quickly and efficiently obtain the distribution of subsurface anomalies without solving large equations. However, the results of direct correlation tomography of gravity anomalies display deep divergence, excessive depth weighting function parameters, and low lateral and vertical resolution between anomalies. According to the fundamental principle of 3D correlation tomography inversion of gravity anomalies, this study introduced the balanced vertical derivative and balanced analytic signal amplitude of gravity anomalies as the edge features to horizontally weight the gravity anomaly correlation tomography, and proposed a more concise depth weighting function. As demonstrated by model tests, the lateral resolution of correlation tomography was improved under the constraint of gravity anomaly edge features, and the vertical resolution of correlation tomography was enhanced using the new depth weighting function. Finally, the method in this study was applied to the actual data of the Australian Olympic Dam polymetallic deposit, yielding consistent weighted tomography results with the actual geological data, thus proving the correctness and effectiveness of the method.
安国强, 鲁宝亮, 高新宇, 朱武, 李柏森. 边缘特征和深度加权约束的重力三维相关成像反演[J]. 物探与化探, 2024, 48(1): 113-124.
AN Guo-Qiang, LU Bao-Liang, GAO Xin-Yu, ZHU Wu, LI Bo-Sen. 3D correlation tomography inversion of gravity anomalies constrained by edge features and depth weighting. Geophysical and Geochemical Exploration, 2024, 48(1): 113-124.
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