[1] Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan,430074, China
[2] State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan,430074, China
[3] Key Laboratory of Geophysical Electromagnetic Probing Technologies of Ministry of Natural Resources, Hebei, Langfang,065000, China
[4] Department of Earth Sciences, Memorial University of Newfoundland, St. John's,NL,A1B 3X5, Canada