准噶尔盆地东部中生代构造迁移规律

摘要

Tectonic migration is a common geological process during basin formation and development. However, little is known about the tectonic migration in the eastern Junggar Basin. This paper focuses on the eastern part of the Junggar Basin to discuss Mesozoic tectonic migration and its mechanism based on our interpretation of seismic profiles and previous structural results in the eastern part of the Junggar Basin. The eastern Junggar Basin was under intraplate setting in Mesozoic-Cenozoic. Under the southward indentation of the Siberian Plate, the tectonic migration was characterized by progressively southward propagating of faulting, sedimentation, depression, termination of faulting in the basin. Finally, this paper discusses the mechanism and processes of Mesozoic tectonic migration from interplate to intraplate. The migration mechanism of the tectonism-sedimentation-basin formation is related to the Mesozoic extrusion tectonics of the basement of the Junggar Basin and the southward indentation of the Mesozoic Siberian Block.%构造迁移是盆地发展演化过程中十分普遍的地质现象，但准噶尔盆地东部地区相关研究程度较低。本文基于对准噶尔盆地东部地区所开展的大量地震剖面解释，并综合前人研究成果，对准噶尔盆地东部地区中生代构造迁移特征进行了系统讨论。准噶尔盆地东部中新生代期间属于陆内，受西伯利亚板块持续向南楔入的远程效应，其构造特征总体表现出自北向南的迁移规律，具体表现为盆地内的逆冲断裂迁移、沉积沉降中心迁移、断陷的萎缩与消亡等自北向南逐步变新。最后，从板缘和板内过程和机制，探讨了该盆地东部的中生代构造迁移机制，这种构造-沉积-成盆等的向盆内变新迁移是中生代以来准噶尔盆地基底向西挤出构造和中生代西伯利亚板块向南楔入的联合效应。