Study on the Deep Electrical Structure and Metallogenic Coupling Mechanism of the Metallogenic Belt in the Eastern South China Block: Evidence from Aeromagnetic Data and Magnetotelluric Sounding

The metallogenic belt in the eastern segment of the South China Block (SCB) ranks among the premier metallogenic provinces in China, characterized by a highly complex and heterogeneous tectonic framework and magmatic activity pattern. This region encompasses three major sub-belts, namely the Middle-Lower Yangtze River Metallogenic Belt, the Qinzhou-Hangzhou Metallogenic Belt, and the Wuyi Mountain Metallogenic Belt, which collectively form an integral component of the tectono-magmatic-mineralization system (TMMS) of the South China continental massif.​

Beyond its fundamental significance in geological research, this metallogenic province serves as a critical natural laboratory for investigating the crust-mantle deep structure coupling relationships and the intricate interactions between geodynamic processes and mineralization mechanisms. To advance the understanding of the deep tectonic attributes and mineralization genesis within this region, this study systematically integrated aeromagnetic anomaly datasets with three-dimensional magnetotelluric (MT) inversion results, thereby revealing distinct differential characteristics of the deep electrical and magnetic structures across the study area.​

Aeromagnetic data interpretations demonstrate that the magnetic anomaly zones within the region exhibit a prominent bimodal trend distribution, dominated by northwest (NW)- and northeast (NE)-oriented belts. These magnetic anomalies show a strong spatial congruence with the major regional fault tectonic systems, and are thus interpreted to delineate the spatial extent of deep-seated tectonic boundaries or the structural framework of metallogenic belts. Electrical structure inversion results indicate that the upper crust of the eastern SCB is predominantly composed of high-resistivity geological bodies, which are inferred to correspond to granitic intrusive complexes or basement metamorphic rock assemblages— a conclusion that is consistent with the well-documented magmatic intrusion history of the region.​

Notably, the spatial distribution of localized banded high-conductivity bodies exhibits a significant correlation with aeromagnetic high-anomaly zones. These conductive anomalies are hypothesized to represent shallow concealed orebodies or geologic units with prospective mineralization indicative value. Within the middle and lower crustal levels, conductive bodies are preferentially concentrated at fault intersection zones. This spatial pattern suggests that tectonic activities have facilitated the upward advection of deep hydrothermal fluids along fault networks, thereby establishing deep-seated mineralization conduits. These hydrothermal flow pathways are intimately linked to the migration and precipitation of ore-forming materials, further underscoring the pivotal regulatory role of geodynamic processes in the mineralization cycle.​

Through the synergistic analysis of aeromagnetic and magnetotelluric (MT) geophysical datasets, this study validates the controlling mechanism of the deep tectonic-hydrothermal fluid coupling system on the metallogenic process. The resultant findings provide a refined geophysical framework, which enhances the reliability of deep mineralization potential assessment and mineral prospecting prediction within the study region.​