Abstract:
The structural belt in the western margin of the Songliao Basin is a key area for studying the formation and evolution of the Songliao basin. However, regarding the structural framework of this structural belt, the activity history and basin control characteristics are still unclear. This fine definition of deep material architecture and Meso-Cenozoic tectonic evolution in this structural belt provide a new evidence for solving this scientific problem. The Bouguer gravity anomaly and comprehensive geophysical profile characteristics indicate that the structural belt in the western margin of the Songliao basin manifests as a zonally distributed supercrustal deep structural belt. Through a comprehensive analysis encompassing the occurrence, nature and kinematics of the tectonic deformation zone, a "Bifurcated Dual Belt" structural framework is proposed. This framework divides into eastern and western zones, exhibiting opposing inclinations. According to the differences of basement background, tectonic pattern and geophysical characteristics of the structural belt development, a “four-stage” distribution framework is established for the north and south section. Additionally, considering the regional tectonic evolution, the structural analysis of deformation zones, and chronology data, the Meso−Cenozoic tectonic activity chronological framework of six periods is restored, including Late Triassic, Middle to Later Jurassic, middle Early Cretaceous, middle Late Cretaceous, Paleocene to Oligocene and Neogenic to Pleistocene. And combined with the basin-controlling influence of the structural belt, it is emphasized that the middle Jurassic and middle Early Cretaceous sedimentary basins, under the control of the exterior basin belt, hold paramount significance for the exploration, provided new basis for the exploration of petroleum reserves of new strata in northeastern China.