党河南山北缘断裂古地震形变带特征研究

The Features of Earthquake Surface Rupture Zone on Northern Margin Fault of Danghe Nanshan

通过对党河南山北缘断裂的野外地貌考察,发现东段保存了长约40km的古地震地表形变带,主要表现为纹沟和高漫滩断错,形成高约0.5m左右的低矮断层陡坎,且活动时代较新。经查阅相关史料和文献,结合最新冲积地貌面的估算年代,推测该地震形变带可能与公元384年、419年、1000年和1297—1303年发生在敦煌附近的4次地震中的某一次地震有关。

Through field investigation we found a 40km-long seismic surface rupture zone, along central and eastern segment of northern margin fault of Danghe Nanshan in Gansu. The fault rupture zone offset the high floodplain of river and the uplift is about 0.5 m. Since the deposits of the high floodplain are young, so that it is reasonable to believe that the active time of the rupture zone was close to the present. According to various historical records and related documents, we identified that four earthquakes had occurred in the vicinity of this fault, and the four historical earthquakes occurred in 384 A.D., 419 A.D., 1000 A.D. and 1297-1303 A.D. respectively. Finally we inferred that the rupture zone may be related to one of the four earthquakes given above.