3-D Magnetotelluric Resistivity Imaging of Nanling-Xuancheng Ore Concentration Area

Abstract

We have implemented a magnetotelluric observation in the Nanling-Xuancheng Ore Concentration Area within the Middle-lower Yangtze River Metallogenic Belts. The magnetotelluric data with 0.001–1000 s period was collected at 843 distinct sites, and all components are handled in the 3-D inversion of the observed dataset. We present the first detailed 3-D resistivity structure beneath the overlying sediment strata of the Nanling-Xuancheng Ore Concentration Area. The shallow parts of the inverted resistivity model fit well with surface geological information and the mineral deposit distribution, while the deep parts suggest a bulk of conductors exist beneath the southern boundary of the Xuancheng Basin. The presence of deep conductors implies an intense deformation and broken structure within this region. Moreover, the comparison with regional geological information, seismic reflection, and gravity data further strengthen this understanding. The study of the 3-D electrical structure is of particular importance for further exploration and research for this region and provides a reference for geophysical prospecting in other areas of the Middle-lower Yangtze River Metallogenic Belts.

Keywords

• Magnetotellurics
• 3-D resistivity imaging
• Nanling-Xuancheng ore concentration area
• the middle-lower Yangtze river metallogenic belts