松辽盆地伸展和反转构造样式

EXTENSIONAL AND INVERSION STRUCTURAL STYLES OF SONGLIAO BASIN

松辽盆地晚中生代经历了裂谷期、后裂谷期和反转期演化阶段。裂谷期盆地在单剪伸展作用下形成，主要断裂大多向东倾，基本结构单元为半地堑和半地垒，下地壳存在向东缓倾的拆离带。后裂谷期热沉降起主导作用，伴以弱伸展，形成同沉积型正断裂。反转期在北西向压扭力作用下，前期正断裂反倾向运动，形成正反转构造带。裂谷期的深断陷和反转期的背斜带是油气生成、聚集的有利部位。

The history of Songliao basin could be divided into rifting. post--rifting and inversion periods. Simple-shear extension controlled the deformation of rifting. All major boundary faults tend to dip easternward and most of their dip angles are low. The fundamental structural units are half-graben and half-horst. The former contains two situation, ones with gentle-dip major .boundary faults and others with steep-dip major boundary faults. The detachment zone is in the lower crust and dips easternwards. Thermal subsidence controlled the formation of postrifting, and formed syn-sedimentary cover-normal faults and anticlines.The regional transcompression controlled the inversion structures.