关键词: 渭河盆地, 活动断裂, 构造地貌

Abstract: Based mainly on geological and geomorphological data collected from the northern boundary fault belt of Weihe Basin, combined with seismic and geophysic evidences found in recent years, the activity and faulting episode of the northern boundary fault belt,the displacements and slip rates of the main faults, as well as the characteristics of spatial and temporal evolution of the fault belt and its mechanics are discussed in this article. The main conclusions are as follows:1. The northern boundary fault belt has experienced eight episodes of faulting since Eocene. The main fault in the belt have an average slip rate ranging from 0.1 to 1.0mm/yr, with the eastern segment of the belt being more active than the western one since Pleiocene.2. The formation of the fault belt is the result of faulting spreading from the center of the basin to the north, but the spreading direction had a change in Pleiocene. The direction of spreading of the east segment changed from N to NW, while the west segment had only a slight change. This difference as well as the difference in fault activity between the east and west segments has a close relation to the influence of Shan-xi shear zone to the Weihe graben.

Key words: Weihe basin, Active -fault, Structural geomorphology