松辽盆地敖古拉-他拉哈断裂带构造演化

敖古拉-他拉哈断裂带与松辽盆地中央拗陷区中浅层系油气聚集密切相关。其发育背景复杂,发育历史漫长,活动期次多,是多期构造运动叠加的结果。通过对敖古拉-他拉哈断裂带系统的构造演化研究,认为断裂带主要经历了3个演化阶段:一是在沙河子期伸展—拉张阶段形成2条北北东向斜列展布的深层主干断裂;二是拗陷期青山口组第一段沉积末期在深层主干断裂上方的T_2反射层上形成密集分布的小断层带,此时断层带的形成和演化明显受到深层断陷展布格局的制约;三是在萎缩期明水组沉积末期的区域挤压作用使得深层主干断裂发生反转,向上扩展形成一个北北东向的断裂带,敖古拉-他拉哈断裂带最终定型。

Tectonic evolution of Aogula-Talaha fault belt in Songliao Basin,China

The Aogula-Talaha fault belt is a complex fault system developed in the middle and shallow layers in the central depression of Songliao Basin.This fault belt is characterized by complex development background,long evolution history,and involved in superposition of multi-stage structural activity.The study of tectonic evolution shows that the Aogula-Talaha fault belt mainly experienced three stages of deformation.The first stage is extensional stage during the deposition of Shahezi Formation,two NNE deep-seated echelon faults formed as the regional major faults.The second stage is depression stage during the deposition of upper Qingshankou Formation,small faults develop intensively above the T2 reflection layer in this stage,and the distribution and evolution of the small fault belts are obviously controlled by the above-mentioned deep-seated main faults.The thirdstage is shrinking period during the deposition of late Mingshui Formation,the previously formeddeep-seated main faults are reversed and extended upward to form a NNE fault belt,the presentAogula-Talaha fault belt,under the influence of regional strike slip.