Abstract: We have studied the relation between the deformation of river terraces and neotectonics activity based on the data of measurement and dating ages of seven fluvial terraces in the Wuwei basin. The deformation characteristics of river terraces reflect the manner of neotectonic activity. The dislocation status of river terraces shows active times, active extents and active intensity of active fault, and the characteristic with migration variations of the most active area in different times. The three Quaternary faults developed since the late Pleistocene epoch in the Wuwei basin and have five periods of activity at least. The active intensity is different for these faults,among which the piedmont fracture activity is the most intensive, and its movement does not stop till present. The activity was stronger about the time 60 ka B.P. in the west and since the time 20 ka B P. in the east.

Key words: River terraces, Quantitative geomorphology, Neotectonism, Wuwei basin

摘要： 根据武威盆地7条河流的阶地测量资料和测年数据探讨了河流阶地变形与新构造活动的关系。河流阶地的变形特征反映出新构造活动的方式,断层活动以逆冲为主,河流阶地的错断状况表明活动断层活动的次数,盆地西部活动至少有7次,东部活动至少有5次;同时可表明断层活动的幅度与强度,以及不同时期活动强烈区具有迁移变化的特点。武威盆地晚更新世以来发育的第四纪断层主要有3条,各条断裂活动次数、强度不尽相同,以山前断裂活动最为强烈,至今活动仍未停息。60ka前后西部活动强烈,20ka以来东强西弱。

关键词: 河流阶地, 定量地貌学, 新构造活动, 武威盆地