3.Late Yanshan stage was compressive crust deformation which not only formed the wedge-type thrust structure but also caused upper Cretaceous Series unconformable contact with lower Cretaceous Series.

• 燕山晚期地壳以挤压逆冲变形为主 ,不仅形成了楔冲式推覆构造 ,也使上白垩统与下白垩统为角度不整合接触。