准噶尔盆地乌夏断裂带构造活动特征

Structural Activity of Wuxia Fault Belt in Junggar Basin

乌夏断裂带位于准噶尔盆地西北缘的东部,是西北缘冲断带的一个重要组成部分。由于多期的构造活动,该区形成了多期的不整合。在断裂带和外缘的隆起区地层剥蚀程度较大,活动时间的厘定比较困难。在对乌夏地区地层的沉积特征和产状分析后发现,乌夏地区经历了早二叠世的前陆盆地发育阶段、二叠纪末的逆掩推覆、三叠纪末的构造强烈隆升、侏罗纪末期的构造微弱活动、至白垩纪的构造定形等多个阶段的演化而形成了现今的面貌。

Wuxia fault belt in the eastern part of northwestern margin of Junggar basin is an important part in the thrust belt of the northwestern margin. There existed multiple unconformities owing to multistage structural activities. However, the large-scale erosions in the uplift areas of the fault belt and the surrounding margins allow the determination of the fault active periods to be difficult. This paper analyzes the sedimentation and the occurrence of the strata in Wuxia area and suggests that Wuxia area underwent the development of foreland basin of Early Permian, the overthrnst nappe of Late Permian, the strong structural uplift of Late Triassic, the weak structural activity of Late Jurassic and the structural shape of Cretaceous followed by finally forming the configuration nowadays.