## 4 Results and Discussion
### Three-Dimensional Metalogenic Prediction
#### 4.3.2 Three-Dimensional Geological-Geophysical Modeling  
The spatial information of different geological interfaces, including faults, lithology, alteration, etc., was extracted based on existing geological data (such as planar geological maps, borehole data, cross-sections, and intermediate plane data). Explicit modeling was performed using platforms like Micromine and GOCAD, and the geological interfaces were constructed through human-computer interaction. The closure function of the 3D modeling software was used to ensure the closure of geological interfaces. Three-dimensional geological models, including carbonatization, chloritization, migmatization, faults, ore bodies, and others, were constructed (Figure 18). Geological structure, alteration, and ore bodies are all controlled by the north-south trending fault, with a westward dip of 40-50\({}^{\circ}\), forming a layered arrangement. As shown in Figure 18, metasomatism is primarily distributed in the upper part of the ore body, while carbonate alteration, chloritization, and other alterations are widely distributed in the ore body and its surrounding areas. The F4 fault has an NE-SW strike, a dip direction of 135\({}^{\circ}\), and a nearly 45\({}^{\circ}\) dip angle, crossing through the entire ore body.  
In this study, 11 exploration line cross-sectional profiles of the mining area in Geomodeller were utilized to delineate the deep geological contact zones and structures. Using the potential field geostatistical method, the interfaces between known geological bodies were interpolated and converted into discrete points, which were then used to divide the adjacent units in three-dimensional space. These cells were merged to construct a three-dimensional voxel model of the geological body. The model was compared with field data to identify and correct any defects, ensuring its consistency with geological principles. Ultimately, a reliable three-dimensional stratigraphic model of the Yanshan Iron Mine was generated (Figure 19). Based on Figures 1c and 19, the Quaternary strata and the Mesoproterozoic Change Cheng Group were identified as the sedimentary cover, unconformably overlying the New Archaean Xintaizi Group, consisting of migmatite, biotite-bearing granulite, and magnetite quartzite. In the deeper mining area, the magnetite quartzite (ore body) and  
The study area covered by the 3D model extended over 1430 m in the E-W direction, 1570 m in the N-S direction, and 1040 m vertically, from 50 m above sea level to \(-990\) m below sea level. The deposit-scale geological model of the study area was constructed using SKUA-GOCAD, and it was composed of 2,120,395 3D-grid voxels with a size of \(10\times 10\times 10\) m. The 3D block model will be used for the subsequent generation of 3D predictor maps and prospectivity maps.  
Furthermore, through Euclidean distance analysis, this study generated the distances of carbonatization, chloritization, migmatization, and faults (Figure 20). These models serve as evidence layers for subsequent mineralization prospectivity analysis at the deposit scale. Furthermore, the constructed 3D ore body model serves as positive samples for subsequent three-dimensional mineralization predictions.