As the need to discovers new mineral deposits and occurrences has intensified in recent years, it has become increasingly apparent that we need to map potentials via integrated information on the basis of metallogeny. Occurrences of mineralization such as tungsten (W), tin (Sn), columbium (Nb), tantalum (Ta), gold (Au), copper (Cu), lead (Pb), zinc (Zn), manganese (Mn) and monazite (Mnz) have been discovered in Rwanda. The objective of this study was to present a regional quantitative mineral prospectivity mapping (MPM) of W, Sn and Nb-Ta mineralization in Rwanda using the random forest (RF) method on the basis of open source data, such as geological maps, Bouguer gravity anomalies, magnetic anomalies, Landsat 8 images, ASTER GDEM, Globeland30, and OpenStreetMap. In addition, a newly introduced interpolation–density–delineation (IDD) process was applied to deal with the blank (masked) areas in remotely sensed mineral alteration extraction. Additionally, a k²-fold cross-validation method was also proposed to obtain more reasonable test errors. Firstly, the metallogenic regularity of W, Sn and Nb-Ta in Rwanda was summarized with the help of articles online. Secondly, original geological, geophysical, and remote sensing data were utilized to generate secondary data. Specifically, the IDD process was applied subsequent to the directed principal component analysis method (DPCA) to reconstruct the alteration anomaly map, and a relevant dataset was formed by the combination of original and secondary data. Thirdly, specific predictor layers for W, Sn and Nb-Ta were selected from relevant data via spatial correlation with known deposits, respectively, and the predictive models were established. Finally, near 26,000 squares were zoned in Rwanda, and RF was optimized and applied, the k²-fold cross-validation method was utilized to assess test errors, metallogenic belts and prospective areas for W, Sn, and Nb-Ta were delineated on the basis of total mineralization potential map and likelihoods map. Results proved that the open source data online were valid for drawing a preliminary mineralization potential map. Furthermore, it was also shown that the IDD method is suitable for the postprocessing of masked alteration anomaly maps. Belt IV-4 in the northwest and belt IV-2, IV-1 in the middle-east of Rwanda, containing a number of prospective areas, possess considerable likelihoods of deposits, and mining in Rwanda is at its dawn, with potential worth expecting.

Many rocks exhibit electrical anisotropic characteristics, leading to artifacts in isotropic inversion of direct current resistivity data. To mitigate this issue, we employ the flexible unstructured finite element method for three-dimensional anisotropic forward modeling and anisotropic inversion for direct current resistivity data. Synthetic inversions further validate algorithm feasibility. The code not only replicates the inversion of principal axis resistivities accomplished by previous researchers but also reconstructs challenging all angle parameters. Comparative analysis of inversion using isotropic and arbitrary anisotropic assumptions reveals that anisotropic inversion accurately recovers the parameters. Models comprising conductive and resistive targets respectively are utilized to stimulate two realistic scenarios. The angle parameters of conductive target are challenging to recover compared to a conductive one with the same anisotropy. We conduct comprehensive experiments to assess the results across various data types. Borehole-generated data enhances the principal resistivities resolution, aligning with the direction of the lines connecting to the boreholes, rather than all ones, whereas conventional surface configurations are unable to accurately capture discrepancies between principal resistivities and Euler angles. Moreover, the investigations confirm the resolvability of each anisotropy component, especially angle parameters, which depends on borehole distribution. These experiments on data-acquisition configurations greatly enhance the practical possibility of successfully collecting data containing anisotropy information, achieving reconstruction of angular parameters, and obtaining better images of principal axis resistivity in practical applications. Even with the correct anisotropic assumption, unreasonable data-acquisition configurations produce inversion results with distortion. Testing with the model containing multiple anisotropic targets further confirms the algorithm’s effectiveness.

The inability of geophysical methods to directly detect gold ore bodies remains a hot topic in the realm of gold geophysical exploration. Through the analysis of high-precision magnetic method, resistivity and induced polarization methods with the gradient arrays, electrical resistivity tomography, and well logging, combined with the discovery of gold mineralization in exploration trenches and boreholes, it has been found that gold mineralization can be classified into two types: terminal and channel. The terminal-type gold mineralization is marked by a buried depth of less than 30 m, accompanied by varying degrees of silicification and pyritization. In contrast, the channel-type of gold mineralization is buried deeper than 30 m and occurs within structural fractures or volcanic breccia mineralized alteration zones. The resistivity difference constitutes a significant geophysical indicator differentiating these two types of gold mineralization. Both types of gold mineralization are located adjacent to IP anomalies, potentially suggesting characteristics of low-sulfur gold mineralization. After comparing several globally typical epithermal gold deposits, we conclude that the findings presented in this paper encapsulate the geophysical traits of an un-eroded, low-sulfidation epithermal gold deposit. These insights offer a valuable reference for the direct detection of similar gold orebodies using geophysical methods.

Abnormally overpressured helium-rich natural gas occurs in dolomite reservoirs beneath gypsum-bearing strata of the Middle Triassic Zhouchongcun Formation in WWY1 Well, Wuwei Depression. Resolving the vertical arrangement of dolomite, gypsum, and shale is therefore critical for evaluating reservoir–seal coupling in this structurally complex setting. Here, we develop a support vector machine (SVM) workflow using acoustic transit time (AC), bulk density (DEN), compensated neutron log (CNL), gamma ray (GR), and spontaneous potential (SP) to refine lithology classification and support lithology-based screening of potential favorable intervals. The reference lithology column integrates mud-logging descriptions, conventional log responses, and stratigraphic information. An RBF-SVM was optimized by grid-search cross-validation, and formation-specific constraints were introduced to suppress lithologies incompatible with the local stratigraphic association. The unconstrained and formation-constrained models yielded matching rates of 89.16% and 90.23%, respectively. Although the numerical increase is modest, the constrained model reduces cross-formation confusion, improves boundary continuity, and produces a more geologically coherent representation of the gypsum–dolomite–shale succession. The model also delineates several thin sublayers supported by synchronous multiparameter anomalies. Independently, epsilon-SVR reconstruction of U, Th, and K logs achieved R² values of 0.979–0.998 and restored continuous element-specific radioactivity information across the interval lacking spectral gamma-ray measurements. Together, these results establish a high-resolution lithological framework for characterizing reservoir–seal architecture and screening dolomite-dominant intervals beneath effective evaporite seals as potential exploration targets. The workflow is designed for single-well geological refinement rather than universal model benchmarking; final evaluation of reservoir quality requires integration with porosity, fracture, core, image-log, pressure, and production-test data.

The inability of geophysical methods to directly detect gold ore bodies remains a hot topic in the realm of gold geophysical exploration. Through the analysis of high-precision magnetic method, resistivity and induced polarization methods with the gradient arrays, electrical resistance tomography , and well logging, combined with the discovery of gold mineralization in exploration trenches and boreholes, it has been found that gold mineralization in the andesite distributed area can be classified into two types: terminal and channel. The terminal-type gold mineralization is marked by a buried depth of less than 30m, accompanied by varying degrees of silicification and pyritization. In contrast, the channel-type of gold mineralization is buried deeper than 30m and occurs within structural fractures or volcanic breccia mineralized alteration zones. The resistivity difference constitutes a significant geophysical indicator differentiating these two types of gold mineralization. Both types of gold mineralization are located adjacent to high-polarization anomaly areas, potentially suggesting characteristics of low-sulfur gold mineralization. These research results provide geophysical technical support for breakthroughs in the exploration of low-sulfide epithermal gold deposits and represent a valuable exploration in the field of directly detecting such gold deposits using geophysical methods.