Abstract: The subsidence history in Junggar Basin was analyzed and modeled with EBM basin modeling system and 2D seismic traverse. The relationship between subsidence rate and tectonic evolution was discussed. The results show that there were some succession and some variety from the early Jurassic epoch to the middle Jurassic epoch. The succession displayed that the subsidence rate was lower in the north than in the south from the early Jurassic epoch to the middle Jurassic epoch in Junggar Basin.The variety displayed that only one subsidence center was developed in the southern margin of Junggar Basin in the early Jurassic epoch. Three subsidence centers were developed in the southern, northeastern and western margins of Junggar Basin respectively in the middle Jurassic epoch. The characteristic of subsidence has a close relationship with tectonic evolution. The stress state was changed from relax stress to extrusion stress from the early Jurassic epoch to the middle Jurassic epoch.

Key words: Junggar Basin, Jurassic period, subsidence history, tectonic evolution, EBM software, numerical simulation

摘要： 采用EBM盆地模拟软件及区域二维地震资料,对准噶尔盆地侏罗纪沉降史进行了模拟和分析,并探讨了沉降特征与构造演化的关系。模拟结果表明,准噶尔盆地早、中侏罗世沉降史既有一定的继承性,又有一定的差异性。继承性表现在早、中侏罗世盆地沉降速率始终为北低南高;差异性表现在:早侏罗世仅在盆地南缘发育单一沉降中心;中侏罗世发育3个沉降中心,分别位于盆地南缘、西缘和东北缘,且以南缘沉降最深,东北缘次之,西缘最弱。其沉降特征与盆地构造演化密不可分,盆地的构造应力状态由早侏罗世发育整体沉降的应力松弛状态演变为中侏罗世发育多个沉降中心的挤压应力状态。

关键词: 准噶尔盆地, 侏罗纪, 沉降史, 构造演化, EBM软件, 数值模拟