Forty-three magnetotelluric (MT) soundings were undertaken along eight profiles at the central portion of the São Francisco Sedimentary Basin, northern region of Minas Gerais State. The study aimed at the mapping of the geoelectrical structure of the basin. The MT profiles were deployed along ten seismic lines covering 11,0000 km² of total area. The MT soundings were irregularly spaced and covered the frequency range from 0.001Hz to 400 Hz, probing the electric structure from the surface to a maximum depth of 60 km. The MT data affected by static shift were corrected by fixing the resistivity value (given by the median) of the first observed conductor. The geoelectric interpretation was based on a rotationally invariant impedance response function. We identified a sequence of conductive and resistive layers, which are related to the sedimentary sequence observed in the São Francisco Basin and its crystalline basement. The results show good agreement with seismic and gravimetric data while showing just a fair agreement with available electrical well log information.
Magnetotelluric; MT; Geoelectric Structure; São Francisco Basin
