Multiscale electromagnetic explorations of the Dachang Sn-polymetallic metallogenic system

To study the geological structure of the Dachang Snpolymetallic in the Danchi metallogenic belt and the constraints on mineralization, Audio magnetotelluric (AMT) data covering the Dachang Sn deposit and magnetotelluric (MT) data in the Danchi metallogenic belt are analyzed and conducted inversion. This allowed us to obtain the near-surface electrical structure of the Dachang deposit and the crustal electrical structure of the Danchi metallogenic belt. Additionally, we collected the regional electrical structure of the Youjiang Basin and redrawn the lithospheric electrical structure of the Danchi metallogenic belt. Given that the Dachang tin polymetallic deposit is classified as a magma-hydrothermal type deposit with deep magma upwelling playing a crucial role in mineralization, we suggest that the near-surface conductor beneath this deposit represents a mineralized alteration area. Furthermore, the crustal (15-25km) and lithospheric conductors beneath the Danchi metallogenic belt are proposed to be electrical imprints associated with ancient magma chambers related to Sn mineralization. The multiscale electrical structures primarily reflect ancient magmatic tectonic events, which provide ascending deep materials and heat. Ultimately, ore-rich magmatic fluids migrated through local structures towards the near surface resulting in Sn polymetallic deposits.