Analogue modeling and structural differences of stepovers of strike slip faults: A case from Shunbei-1 fault of Tarim Basin

Stepovers in strike-slip fault zones are usually associated with both releasing bends and restraining bends,whose occurrence and evolution are closely related with the hydrocarbon accumulation. Specifically, the structural difference between these two structures could significantly influence hydrocarbon migration and accumulation.Exploration data of the Shunbei-1 fault in the Shuntuoguole area of the Tarim Basin reflect that hydrocarbons are more enriched in releasing bends than the restraining bends. Based on the studies of structural characteristics of the Shunbei-1Fault, we conducted the simulation experiments to investigate the internal characteristics of these stepovers. Our results suggest that multiple sets of Riedel（R） shears and P shears are developed in the releasing bends, constituting an echelon pattern fault system, which shows a small range of deformation in the plan view and a large vertical displacement at the stepover in the section view. In contrast, only one set of R shear, one set of P she