【摘要】 冀西北坝上高原是河北省的三大地貌单元之一,新构造活动强烈,间歇性断块升降十分明显,主要表现为多级层状地貌、强烈的火山活动、盆地迁移、断裂活动及地震等。区内发育北台期及唐县期两期夷平面,其海拔高度分别为1 700 m、1 500 m左右,其形成时代分别为晚白垩纪—始新世初和中新世未—上新世初。区内发育Ⅰ~Ⅲ级阶地,Ⅰ级阶地河拔高度为1~2 m,形成于晚全新世早期;Ⅱ级阶地河拔高度为6~12 m,形成于早全新世初期;Ⅲ级阶地河拔高度为25~30 m,形成于晚更新世晚期。更多还原

【Abstract】 Bashang highland of northwestern Hebei province is one of three great landform unions,where neotectonic movement happens very fiercely,and intermission vertical displacement among the differential blocks is very obviously.It shows the multilevel layer landform,fierce volcano movement,basin movement,rupture action,and earthquake et al.There are Beitai stage and Tangxian stage planation surface,with about 1 700 meters and 1 500 meters height above the sea level,which formed in late Cretaceous Period - early Eocene Epoch and Miocene Epoch -Pliocene Epoch respectively.There are three layer(Ⅰ-Ⅲ) terraces in the area.Ⅰ layer terrace formed in the early period of late Holocene epoch with 1-2 meter height above the river level.Ⅱ layer terrace formed in the initial stage of early Holocene epoch with 6-12 meter height above the river level.And Ⅲ layer terrace formed in the later period of the late Pleistocene epoch with 25-30 meter height above the river level.From old to new,the basin moves from west to east in the place.The basin belongs to fault basin and obviously controlled by the ruptures.更多还原