3D tectonophysical modelling of the inversion structures in the latest Cretaceous in the northern Songliao Basin
Chen Junliang1, Li Zhongquan2, Ying Danlin3, Lin Chunhua4
1. Department of Geology, Chengda University of Technology, Chengdu 610059;
2. Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing, Heilongjiang 163712;
3. Institute of Exploration and Development of Southwest Oil-Gaa Field Branch Company, China National Petroleum Corp., Chengdu 610051
Tectonophysical modelling plays an important role in analyzing the inversion mechanism, explaining the seismic data and establishing the tectonic model.Based on a detailed study on the basemental structures,basin evolution and reformation,the paper carried on a 3 D tectonophysical modelling of the Songliao Basin for six times,and explored a dynamic process of inversion deformation in later stage of a fault-depressing basin, which demonstrated that the anticlinal belts with multiple orientation might be created by the same stress field,constrained by the structural boundaries in the basement.In addition,the pre-existed structural boundaries could decide the occurrence of later deformation,namely,the gentle-dipping side of fault deformed first,the corresponding anticlinal belt having a steep-dipping limb,and more violent folding.Also, the pre-existed boundaries controlled developing of the en echelon normal faults.These anticlinal belts created after sedimentary period of the Mingshui Formation.In other words,the inversion of the Songliao Basin occurred in the Yanshanian movement in the latest Cretaceous, which constrained the Cenozoic sedimentation in Songliao area.