关键词: 反转构造, 断弯褶皱, 断展褶皱, 油气田, 松辽盆地

Abstract: Songliao basin is one of giant rift basins formed in the late Mesozoic.Its evolution represents successively rifting stage,postrifting stage and compression-subsidence stage.During its evolution process,there were three times of tectonic inversion:the first one occurred in the rifting stage,being a negative inversion related to the forming of fault depressions;the second and third ones occurred respectively at the end of the rifting stage and at the end of postrifting stage,both being positive inversions,which remoulded the protobasin.The negative inversion represented the reviving activities of early thrust faults(system)with upthrows sliding downward along the trend. The positive inversion process was contrary to the negative one,formed fault-bend and fault-propagation folds.The Precenozoic framework of structures in Songliao basin formed in the third inversion,horizontally forming structural belts along the trends NNE-NE with transformation intensity weakening from east toward west and from south toward north,and also showing a relationship with the distribution of oil and gas fields.

Key words: mversian structures, fault-bend, folds fault-propagation folds, oil and gas fields, Songliao basin