## 6 Conclusions  
A new geophysical exploration model was proposed, which was integrated as follows: geophysical model-numerical simulation-exploration method selection- field experiments-electrical structure interpretation. Through the practical application in the Jinding lead-zinc mining area, the new geophysical exploration model could provide an effective theoretical basis for the selection and effectiveness of geophysical exploration methods, and the model improves the geological effectiveness of exploration.  
Figure 18: Location of (a) Line 700 and (b) Line 1100 and their electrical structure profiles.  
A new simulation algorithm, the coupled finite element-infinite element method, was proposed in this paper. Compared to the traditional large-scale finite element method, the method has a discretization area that was only 1% of the traditional computational domain, a reduction of 40% in the total number of nodal degrees of freedom, a decrease of 57% in memory consumption, and a reduction of 45% in computation time. Therefore, we can show that the new CSAMT simulation algorithm proposed has significant advantages such as a small discretization area, fewer computational nodes, and a faster solution speed.  
Compared to traditional CSAMT exploration, new signal-to-noise ratio experiments and different acquisition time experiments were conducted to obtain high-quality data. In the SNR experiments, a new noise source was defined by using the signal collected when CSAMT was not transmitting as the noise source, which included natural field source signals and noise signals. By calculating the SNR, the transmitted signal intensity was adjusted reasonably, so the quality of data acquisition could be more strictly and quantitatively evaluated. Additionally, different acquisition time experiments were compared, and the results showed that by extending the data acquisition time, the quality of CSAMT low-frequency data could be significantly improved, and the transitional and near-field characteristics of the Cagniard apparent resistivity curve could become more pronounced.  
By using two-dimensional continuous medium inversion, the electrical distribution at a depth of 1 km below each survey line in the Jinding lead-zinc mining area was obtained. At the same time, by interpreting the electrical structure of the survey lines, the electrical characteristics of the lithologic system in the Jinding lead-zinc mining area were revealed. These results provide reliable data support for the geological genesis and metallogenic model of the Jinding lead-zinc deposit.  
Project conception: [PERSON] and J.T.; field data acquisition plan: [PERSON] and J.L.; noise experiment and acquisition time experiment plan: [PERSON] and X.X.; data organization: [PERSON]; forward and inversion calculations: [PERSON] and [PERSON]; electrical structure interpretation: [PERSON] and [PERSON]; writing--original draft preparation: [PERSON]; writing--review and editing: [PERSON] and [PERSON]; supervision: [PERSON]. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Hunan Provincial Natural Science Foundation of China, funding number 2021 JJ40024, and the Basic Applied Research and Soft Science Research Plan of Yiyang, funding number Yi Caijiao Zhi [2022] 108.  
Not applicable.  
All experimental data in this work are available upon request.  
I would like to express my gratitude to all members who participated in the CSAMT data collection and processing at the Jinding lead-zinc mining area.  
The authors declare no conflicts of interest.