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D structures of velocity and temperature are obtained using the data of P-wave veloc-ity and heat flow in North China (105E—124E, 30N—42N). Taking into account the effect of three main rheological mechanisms, namely friction sliding, brittle fracture and creep in the litho-sphere, the 3-D structures of the rheological strength and viscosity in the lithosphere in North China are calculated. The results show that the strength and viscosity in the lithosphere have lay-ering characteristics. Under the strain rate of 10-15 s-1, the upper part of the upper crust is in the brittle region and the lower part of the upper crust may be in the ductile region dominated by creep; the middle crust can be in the brittle region dominated by brittle fracture, or the upper layer of brit-tle fracture and lower layer of creep ductile; the lower crust almost is in the creep region dominated by creep. In addition, the strength varies horizontally, which has a close relationship with geotec-tonics. The influence of velocity structure and temperature structure on the rheological structure is discussed and some suggestions to improve the study of lithospheric rheological structure are put forward.
D structures of velocity and temperature are obtained using the data of P-wave veloc-ity and heat flow in North China (105E-124E, 30N-42N). Taking into account the effect of three main rheological mechanisms, namely friction sliding, brittle fracture and creep in the litho-sphere, the 3-D structures of the rheological strength and viscosity in the lithosphere in North China are calculated. The results show that the strength and viscosity in the lithosphere have lay-ering characteristics. Under the strain rate of 10-15 s-1, the upper part of the upper crust is in the brittle region and the lower part of the upper crust may be in the ductile region dominated by creep; the middle crust can be in the brittle region dominated by brittle fracture, or the upper layer of brit-tle fracture and lower layer of creep ductile; the lower crust almost is in the creep region dominated by creep. In addition, the strength varies horizontally, which has close relationship with geotec-tonics. The in fluence of velocity structure and temperature structure on the rheological structure is discussed and some suggestions to improve the study of lithospheric rheological structure are forward.