塔里木盆地构造—层序分析

Analysis on the Tectonic-Stratigraphic Sequences in the Tarim Basin

塔里木盆地自震旦系—第四系可划分为3个巨层序组,6个Ⅰ级层序(巨层序),16个Ⅱ级层序(超层序)和42个Ⅲ级层序(层序)。3个巨层序组反映了区域构造发展的3个大地构造旋回及其相应的区域大地构造事件在其巨层序组演化过程中的影响。其中,Ⅰ级层序属于同一构造运动体制的产物;Ⅱ级层序属于同一构造背景下的同一期盆地演化或属于同一较长周期海平面变化旋回的产物;Ⅲ级层序属同一期盆地中同一构造演化阶段或受短周期的海平面旋回性变化、沉积物供给速率变化控制。层序地层的研究表明,构造作用在大部分层序形成中起着决定性的作用,表现在不但高级别的层序地层单元主要受大区域性构造作用的控制,许多较低级的层序地层单元也受小区域构造作用的控制。全球海平面的变化往往在某些盆地稳定演化时期起着重要的作用。

The Sinian-Quaternary in the Tarim basin can be divided into 3 megasequence sets which represent the features of three regional tectonic cycles and the effects of the related regional tectonic episode to the evolution of the megasequence sets, 6 Ⅰ order sequences (megasequence) formed under the same tectonic regime, 16 Ⅱ order sequences (supersequence) formed in a cycle of basin evolution under the same tectonic settings or in a relatively cycle of relative sea-level changes and 42 Ⅲ order sequences (sequence) formed in the same tectonic stage during a cycle of basin evolution or in a relatively cycle of relative sea level change. The tectonism controlled the formtion of most of the sequences. The eustasy sometimes played a crucial role in the stable evolution period of some basins.