松辽盆地南缘十屋断陷构造物理模拟研究

Physical simulating model of Shiwu faulted depression structure in Songliao basin,China

松辽盆地十屋断陷早期伸展阶段形成断陷和坳陷沉积,晚期挤压阶段发生盆地反转。采用铲形和直线形2种边界断层模拟十屋断陷的形成和演化过程。模拟实验结果表明,较陡的主干断层控制的半地堑断陷在侧向挤压过程中发生盆地反转,但是早期形成的正断层不一定发育成为反转断层,而是正断层的倾角变陡,并导致在断陷内的上部盖层中发育形成新的逆断层。这一实验结果较好地解释了松辽盆地十屋断陷的构造演化特征,即断陷期形成的正断层在后期反转构造中受到挤压发生产状变化并在拗陷期沉积盖层中发育逆断层。

In the early stage of Shiwu depression movement of Songliao basin, there was faulting and depression sedimentation, and basin reversing happened at the later stage. In this paper we simulated the formation and developing process by means of both shovel shape and linear boundary fault, which indicated that half of the graben fi＇acture controlled by the steeper fault led to basin reversing during lateral compression. It provides a reasonable explanation for tectonic evolution of Shiwu faulted depression structure in Songliao basin, that is the normal faults formed during depression movement was compressed in later-stage reversing, which resulted in occurrence change and developed into reverse fault within sedimentary cover in depression phase.