A comparative study on the application performance of time-frequency and audio magnetotelluric methods in deep copper exploration

The Lala copper deposit in Sichuan Province is characterized by a thick low-resistivity cover, a great burial depth, and thin ore layers. By comparing the differences in the applicability of the time-frequency electromagnetic method (TFEM) and the audio magnetotelluric method (AMT) to deep copper exploration in this deposit, this study aims to address the issue of insufficient accuracy in the identification of deep targets. The TFEM and AMT methods were applied to the study area for tests. The comparison of the test results with existing drilling data revealed that the TFEM method exhibited a higher resolution than the AMT method and effectively identified the positions of ore layers or zone-bearing layers. These characteristics establish the TFEM method as a preferred approach for the detailed survey of key target areas. Nevertheless, the AMT method remains cost-effective for preliminary exploration of shallow structures. This study offers a valuable case for enriching geophysical methods for deep ore exploration in the study area.