柴达木盆地西北部新生代褶皱-冲断带形成机制的物理模拟

通过构造物理模拟的方法,根据柴达木盆地西北部实际地质条件设计模型,对该区反S形褶皱-冲断带的形成机制进行研究。结果表明:柴达木盆地西北部褶皱-冲断带的形成受赛什腾山弧形刚性边界和巨厚下侏罗统泥岩滑脱层的控制;褶皱-冲断带自北东向南西逐步扩展,其形态也从弧形逐渐过渡为直线形;挤压应变主要集中在褶皱两侧的逆冲断裂之中,最大值通常出现在新产生的活跃构造带上,剪切应变集中在与挤压方向斜交的褶皱部位。

Physical modeling of Cenozoic fold-thrust belts formation mechanism in northwestern Qaidam Basin

By tectonic physical modeling, geologic models were developed based on the geological conditions of the northwestern part of Qaidam Basin. And the formation mechanisms of fold-thrust belts were studied in this region. The results show that the formation of fold-thrust belts in the region is controlled by rigid arc-shaped boundary of Saishenteng mountain and detachment layer of Jurassic mudstone with huge thickness. Fold-and-thrust belts were gradually propagated from the northwest to the southeast, with the shapes changing from curved to straight. The shortening strains accumulated mainly on the thrusts on the both sides of anticlines and their extremum concentrated in the newly generated active part of the fold-thrust belts. The shear strain distributed at the fold-thrust belt intersected with extrusion direction.