Caledonian movement made the north Qilian geosyncline become a folded zone diving to Alashan paleoland so that the geosyncline Vanished, resulting in a foundation for the apprearance of basin.

• 加里东运动使北祁连地槽最终回返褶皱向阿拉善古陆俯冲,结束了地槽发展阶段,奠定了盆地的基础。