Electrical Structure of the Middle Segment of the Tancheng‐Lujiang Fault Zone and Its Geological Implications

AbstractTancheng‐Lujiang fault zone is an important strike‐slip fault system in eastern China continent, and has significant status to study the forming, evolution and current structure of China continent. The magnetotelluric (MT) sounding profile from Alxa Zuoqi to Rizhao city of Shandong province crossed the middle part of Tancheng‐Lujiang fault zone at Juxian of Shandong province, where its strike angle is about NE20 degree as shown by strike analysis. The resistivity model of 2D MT inversion shows that the width of Tancheng‐Lujiang fault zone is about 30 km at where the profile crossed it, the main part of Tancheng‐Lujiang fault zone consists of two deep and steep faults, the western one dips to west steeply with a dip angle about 70 degrees and its penetration depth is about 60 km, the eastern one dips to east with a dip angle 60~80 degrees and its penetration depth is between 80 and 100 km. Both of these two faults cut through the crust, but limited in the lithosphere. The crust is resistive from eastern edge of Tancheng‐Lujiang fault zone to Rizhao city, which is very different to the west of the fault zone, this fact indicates that Tancheng‐Lujiang fault zone is the boundary between North China block and Jiao‐Liao‐Korea block.