## 4 Results and Discussion  
A color-shaded map of the study area was generated using reduced-to-the-pole data (Figure 6), providing a visual representation of the regional magnetic field characteristics and their correlation with the regional geological structural background. The magnetic field of the study area is characterized by multiple northeast-southwest trending anomalous strips (striped magnetic anomaly, SMA) in the northwest region, a blocky magnetic anomaly zone (blocky magnetic anomaly, BMA) in the southeast region, and several isolated positive anomalies (isolated magnetic anomaly, IMA) dispersed throughout the area. The DZL ore deposit is located in SMA1, and SMA2 is located in the northwest of the study area. In terms of spatial position, they correspond to the exposed areas of the Cretaceous intrusive rocks on the geological map. SMA1 extends from the northeast corner of the study area to the southwest, passing through the middle of the study area, where the DZL ore deposit is located. The magnetic field intensity in this area is relatively high, with most of the magnetic anomaly intensities ranging from 200 nT to 300 nT, mainly caused by the intrusive rocks in this area, which is also a reflection of the known main ore-bearing rocks in the study area. Compared to the eastern segment, the magnetic field intensity of the western segment of SMA1 is relatively weak, which may be due to the weakening of the magnetic source, reduction in size, or increase in burial depth. SMA2 is located in the northwest of the study area, with a similar trend to SMA1, but with a slightly weaker intensity. The magnetic anomaly intensity increases from tens of nano-Tesla to over 200 nT from east to west. SMA2 extends out of the study area from both the west and north sides, which should be caused by intrusive rocks. BMA occupies the entire southeastern part of the study area, which is a blocky weakly magnetic background field with occasional small positive magnetic anomalies. BMA reflects the overall magnetic background of the study area, mainly due to the non-magnetic or weakly magnetic sedimentary layers. There are a few isolated positive anomalies and weak linear anomalies within BMA, which may indicate the presence of small-scale high-magnetic rocks. IMA1 to IMA5 are representative isolated positive magnetic anomalies with relatively high magnetic field intensities within the study area, mainly distributed in the southwestern part of the study area, outside of SMAs and BMA, which should be a reflection of high-magnetic intrusive rocks. We know that the DZL ore deposit is developed in the silicate rocks at the contact zone of the intrusive rocks, so we used aeromagnetic data to identify potential intrusive rocks in the study area, and the boundary of the rocks is a favorable area for future mineral exploration. Figure 7 shows the tilt angle map of the study area. The zero-contour lines can be used to indicate the boundaries of the magnetic source (mainly intrusive rocks in this study). Figure 6: The reduced-to-the-pole magnetic field map of the DZL area. The contour map was created based on the gridded reduced-to-magnetic-pole data, with the gridding method being minimum curvature and the grid spacing being 50 m. The contour line spacing on the map is 10 nT. The white dashed lines indicate the approximate extent of the SMAs and BMA. In Figure 7, purple dashed lines are used to highlight the locations of magnetic susceptibility changes (i.e., zero-value lines). The warm-colored high-value areas inside the dashed lines are closer to the magnetic source center, while the cool-colored low-value areas outside the dashed lines represent regions farther away from the magnetic source. We find that the DZL ore deposit, which is currently being mined, is precisely located on the zero-value lines, consistent with the phenomenon mentioned earlier that it is developed in the contact zone between the rocks and the surrounding rocks.