Abstract

The Sốp Cộp - Sông Mã magnetotelluric (MT) sounding has been carried out in Sơn La Province. The sounding section is over ~35 km long, consisting of 12 stations spaced at ~2.5 km. The 2D MT inversion of the obtained data was made. The results of this 2D inversion has allowed us to determine the location, depth and dip direction of the following faults: The Sông Mã Fault, and Sốp Cộp - Quan Sơn Fault. These are deep-seated faults manifestated by by sharp boundaries of resistivity changes. Onver the Sốp Cộp - Sông Mã geoelectrical section, the geoelectrical structure of the Earth crust consists of three typical layers, of which the middle layer has higher resistivity than the upper and lower ones.