Structural characteristics of strike-slip faults in the Luzhou-Yunjin area,southern Sichuan Basin
Multiple layers detached thrust and fold systems dominated the deformation of the Luzhou-Yunjin area,while,strike-slip faults also developed in the area.Precise plane-section interpretation and classification of thrust faults and strike-slip faults are of great significances for understanding deformation patterns and fault systems of the area.Through structural interpretation and well-seismic calibration analysis based on high-precision 3D seismic data and drilling data,conclusions are as follows:1)the superimposing deformation of reverse faults and fold belts with different grades and strikes of NEE,NW,near EW,etc.,constitute the multi-layer detached thrust and fold system in Luzhou-Yunjin area.2)Four main strike-slip fault zones developed in the area,presenting the deformation features of extensional grabens on planes and the"Y"shaped negative flower structures on sections.Among them,the No.1 strike-slip fault zone is nearly north-south strike,and formed under left-lateral shear.While,the No.2 and No.3 strike-slip fault zones are composed of multiple secondary fault zones or small normal faults with left-step arrangements,which formed under the regional right-lateral shear background.The No.1,No.2 and No.3 strike-slip fault zones in southern Sichuan Basin was formed before the Permian(inferred as Devonian to Carboniferous).On the other hand,the No.4 strike-slip fault zone that developed along the ridge of anticline was formed under right-lateral shear after Permian(inferred during the Early to Middle Triassic).The No.4 strike-slip fault zone and local segments of the No.3 strike-slip fault zone,as well as the thrust faults that mainly developed in the Permian-Triassic provided effect migration pathways for multiple sets of sources and reservoirs.And they also resulted in the formation of fault-controlled fracture-cavity reservoirs,which in general are beneficial to gas accumulation in reservoirs of Qixia Formation,2nd member of Maokou Formation,and Jialingjiang Formation,etc.
Strike-slip faultThrust and fold structuresGenetic mechanismsOil and gasLuzhou-Yunjin areaSouthern Sichuan Basin
万方数据
维普
