论反转构造

ON INVERSION TECTONICS AND STRUCTURES

反转构造指同一断裂面出现两期力学性质和运动方向都相反的构造组合。依反转构造的尺度有断层的反转，盆地的反转及盆地系的反转。负反转包括三类型式，发生在裂谷期的正反转有三类型式，发生在后裂谷期的有四种型式。反转构造的成因有应力型、重力型和热力型。大型的负反转与裂陷作用复合可以使地壳厚度显著减薄。小型的反转常是重力作用的结果。正反转构造的变形序列依此为隐伏型断展褶皱、穿透型断展褶皱、断弯褶皱、截弯取直型复式反转、复杂构造如双重构造等。反转构造和油气有密切的关系。

Inversion structures occur when a fault has two phases of deformations of dramatically different geodynamics.Inversion of tectonic subsidence and uplift occurring in the same region is called inversion tectonics.Negative inversion,concerning reaction of former thrust fold belts under grativity and extension,could be classified into three types.Local negative inversion has something to do with gravity,but regional inversion is related with extension.Positive inversion could take place during rifting and post rifting thermal periods,and first form three types of structures and then four types(simple and break through fault propagation folds, fault bend folds and short cut composite inversion fault folds etc.) showed in back thrusting,ramp and imbricate combination.Inversion is caused by geostress,gravity and thermal geodynamics.It could generate anticlinal traps,extensional fissions in traps,lower compression traps and oil and gas movement from high pressure to lower pressure area.Fault propagation fold is beneficial to oil and gas trapping.