斜向挤压构造的物理模拟及其对焉耆盆地构造解释

Physical modeling of structures by oblique compression and its implication for formation of structures in the Yanqi Basin, northwestern China

摘要: 针对焉耆盆地的实际构造问题,设计了刚性边界基底均匀收缩斜向挤压砂箱实验模型。实验结果表明,斜向挤压情况下,挤压带边界方向和挤压方向对构造线走向起控制作用,其中边界方向的控制作用更加显著。斜向挤压作用与压扭作用不完全等同,斜向挤压虽然也有走滑分量,但被均匀地分布在整个变形区域,故不一定形成具明显走滑特征的断层。笔者认为,对于焉耆盆地这类构造的形成,用斜向挤压作用可以得到更好的解释。

Abstract: A sandbox model with rigid border,homogeneously contraction base and oblique compression is prepared to investigate the formation of structures in the Yanqi Basin.The experimental results indicate that both border orientation and compression direction control the direction of stuctures in a compression region suffering oblique compression.But the border orientation acts more obvious.Oblique compression is not completely equal to transpressional deformation.Although oblique compression possesses strike-slip deformation component,it does not surely produce faults of obvious strike-slip movement because the strike-ship deformation component is homogeneously permeated in deformation area. Based on the experimental result, it is proposed that oblique compression mechanism can be used to better explain the formation of structures in basins just like the Yanqi Basin.