Detachment Fault Characteristics And Analogue Modelling Of Luxi Block

Based on the field survey and well geology and seismic data,this paper researched the geometric and kinematic characteristics of normal faults and strike-slip faults.On this basis,using the analogue modeling,and the similarity theory is used to analyze the deep development model and the dynamic mechanism of basin formation in the study area since the Mesozoic.With the large angle of inclination,the NW-trending and nearly EW-trending Detachment faults which are parallel aligning from south to north in Luxi block.The shallow angle of inclination is large,and the inclination angle is gradually slowed down.With large scales,long developing time and deep cutting,the detachment faults control the sediment of the half-grabent that hasformed since late Mesozoic.Common fault breccia,fractured rock,fault mud,and scratches in faults indicate that the faults in this area have experienced multi-phase tectonic activities.In the late Mesozoic Yanshanian period of the study area,the structural negative reversal occurred and began to become a normal fault.In the Paleogene to Eocene,the Luxi region was strongly stretched.In the Neogene,the stretching effect of the study area is weakened,and the detachment fault is no longer developed.Its depth is 14-30 km.Through calculation,the faults of the Luxi block detachment faults are generated at the depths of 14km(Wensi fault),29km(Mengshan fault),26km(Xintai-Duozhuang fault)and 27km(Taishan-Tongyedian fault).The kinematics study of the Luxi block shows that the balance profile recovery shows that the Triassic compression is 6.3 km,the Luxi area is squeezed,and the NW is formed by the reverse fault;the Early Jurassic is subjected to extrusion;-The Early Cretaceous stretch was 3.4km and was stretched;the Paleogene stretch was 9.8km and the Neogene stretch was1.4km,of which the Neogene stretch was the largest.According to the vertical activity rate of the fault,the Luxi block fault-concave fault: the Wenyu fault,the Mengshan fault,the Xintai-Yizhuang fault,and the Taishan-Tongyedian fault were reversed from the fault to the normal fault at the end of the Triassic.The rate of activity in the Paleogene fault reached the maximum,and the tectonic activity migrated from south to north.In the Mesozoic,the lower part of the detachment of the fault in the study area after the formation of the fault,Mengshan,Lianhua Mountain and Taishan began to rise in the late Cretaceous.Based on the study of the outcrop of the Luxi block fault,this paper uses the similarity criterion to construct the physical simulation.Based on the structural physics simulation experiment,the formation mechanism of the detachment fault in the study area is analyzed,which is the damage of the North China Craton.Provide a certain structural basis.