Formation Mechanism And Modeling Of Corrugation Of The Jinzhou Detachment Fault From The Liaonan Metamorphic Core Complex

South Liaoning area is generally interpreted as one of areas of North China Craton distraction, where typical metamorphic core complex, such as the Liaonan complex, detachment fault, e.g., Dayingzi faults, and rift basins, such as Dandong basin, Benxi basin and Tongjiabao basin, occurred widely during the Late Mesozoic. Systematic analyses were carried out in this study on the corrugation-like Jinzhou detachment fault in the Liaonan complex, which focus on the characteristics of the geometry and kinematic of the fault on the basis of field investigation, EBSD analysis, and microscope observation, in an attempting to understand the mechanism of the formation of the corrugation-like fault. Additionally, an experimental tectonic study was conducted to simulate the formation of the corrugation-like fault under specified stress conditions. The Yinmawanshan granite was involved in the detachment fault on the north, whereas, was not included in the fault on the south part of the study area, suggesting that the fault plane situated deeper in the north than in the south part. All the EBSD results of the metamorphic rocks in the Jinzhou detachment fault show Y-or Z-axis fabric, indicating the deformations were occurred at low or medium temperature. In order to search the mechanism of the corrugation-like structure of Jinzhou detachment faul, we carry out two simulation experiments:one is pull the both side of the sandbox, the other is pull the both sides meanwhile push the virticle side. The result of the simulation experiment shows that the corrugation-like fault can occur at a pure extensional environment, thus the extensional tectonics played a key role to to the development of the corrugation-like structure of Jinzhou detachment fault.