【摘要】 结合多年野外实际观察和吴忱关于地文期的最新研究成果，论证了在北台期夷平面之下尚有一级晚于北台期的夷平面存在，它的形成时代为渐新世。北台期则在中—晚白垩世。指出了确定夷平面和夷平面时代的依据，不能像Ｗｉｌｉｓ（１９０７）那样，只根据地形面切削了燕山期的地质构造确定。必须根据形态、沉积、旋回、层位和岩溶等综合证据，进行区划分析。最后，讨论了这两级古夷平面在地震地貌研究中的作用。更多还原

【Abstract】 Combining the field observation for many years with the new research achievement of the physiographic stage by Wu Cheng,it is demonstrated that there was a planation surface later than the Beitai stage under the planation surface of Beitai stage,its forming chorn was Oligocene Epoch,and Beitai stage was middle to late Cretaceous period.It is suggested that the basis defining the planation surface and its chorn must be the comprehensive evidences of the shape,the depositional cycle,the position and the karst,but not only based on Yenshan structure cut by the topographic surface like willis(1907).Finally,discusses the effect of both the palaeoplanaiton surfaces in the seismic morphological analysis.更多还原