The deep electrical structure across Anqing-Guichi ore concentration area

The middle and lower reaches of the Yangtze River have experienced multiple stages of geological evolution and are rich in mineral resources. In this paper, a two-dimensional electrical structure model covering the Dabie orogenic belt and the Lower Yangtze block was constructed by inverting a long magnetotelluric profile passing through the Anqing-Guichi ore concentration area by sub-band and sub-segment inversion scheme. According to the obtained electrical structure, the lithospheric structure beneath the ore concentration area is significantly different from that of the adjacent areas. Both the crusts under Dabie orogenic belt and between Jiangnan uplift belt and Zhegan depression are characterized by high resistivity, while the lithospheric upper mantle between Lower Yangtze depression and Jiangnan uplift belt is electrically conductive with a deep conductor extending upward to the conductors in the upper crust. The metallogenic mechanism of Anqing-Guichi ore concentration area was mainly the Yanshanian intra-continental subduction and the early Cretaceous extension deformation. The thickening and sinking of the lower crust and the abundant fault system in the upper crust underneath the ore concentration area may have played an important role in mineralization.