within the North China Craton by fitting the real MT data collected there. Finally, we establish the 3-D lithospheric resistivity model for the Proterozoic Wutai-Hengshan Mts. Then, the reliability of this procedure is certificated by 1-D, 2-D and 3-D and anisotropic forward modeling tests. The calculated responses include the surface electric and magnetic field components, impedance components, magnetic transfer functions and phase tensors. In order to improve the discretization technique of computing area, we use the combination of Matlab and COMSOL Multiphysics to establish a general procedure for calculating the MT responses for arbitrary resistivity models. Using the adaptive unstructured grid, the calculation is much faster. In addition, its AC/DC and RF module can be used to easily calculate the electromagnetic responses of complex geological structures. It achieves highly accurate numerical simulations with high computational performance and outstanding multi-field bi-directional coupling analysis capability. COMSOL Multiphysics is a cross-platform finite element analysis, solver and multiphysics full-coupling simulation software. However, the complexity of mesh gridding and limitation of computer capacity has been affecting its application. By contrast, the finite element method is more accurate in calculating complex and irregular 3-D region and has lower requirement of function smoothness. But its structured mesh gridding cannot be well adapted for the conditions with arbitrary topography or complex tectonic structures. Yan, J.Īt present, most magnetotelluric (MT) forward modelling and inversion codes are based on finite difference method. The Application of COMSOL Multiphysics Package on the Modelling of Complex 3-D Lithospheric Electrical Resistivity Structures - A Case Study from the Proterozoic Orogenic belt within the North China Craton