Different tectonic style exists in the upper and lower layers of the yanshanian boundary . the lower layers takes on the tectonic style of thrust fault and nappel . the upper layers hi step positive fault 2 、盆地燕山期构造界面上下不同构造层具有完全不同的构造样式，构造界面下伏构造层呈现冲断褶皱、推覆构造样式，构造界面上覆构造样式为阶梯状正断层，整体呈现“双层”结构型式。
