阜新-义县盆地构造演化及应力场光弹性模拟分析

阜新盆地的形成主要受北西向构造活动控制,在北西向构造形成时的北北东—南南西向挤压应力作用下,成盆前的北北东、南北和近南北向断裂受引张作用,导致内倾断裂以正断层形式作张性下滑,形成断陷,使阜新盆地扩张。早白垩世以后,新华夏系北西西—南东东挤压应力重新活动,北北东、南北和近南北向断裂遭受挤压,断陷作用消失,进而以压扭性方式重新活动,对阜新盆地起着破坏和改造作用。

STRUCTURAL EVOLUTION AND PHOTOELASTIC MODELLING ANALYSIS OF STRESS FIELD OF FUXIN-YIXIAN BASIN

The present paper deals with the formation and evolution of the Fuxin-Yixian basin by analysing various geological structures in the basin and neighbouring area. The authors consider that the formation of the Fuxin-Yixian basin is controlled by tectonic activity giving rise to NW-trending structures. Photoelastic modelling was conducted to simulate the stress field in this area during and after the formation of the basin. When the NW-trending structures were formed, the area was compressed in NNE-SSW direction. Leading to downward movements of the pre-existing NNE-SSW, N-S, and north by east inward dipping faults as a result of extension. The basin was thus expanded. Because of the renewed activity of the Neocatha-ysian tectonic system after early Cretaceous the NNE-SSW, N-S and north by east faults suffered compression, resulting in thrusting instead of down-faulting. The basin was so changed and modified by the structures of Neoca-thaysian tectonic system.