Abstract: This paper deals with the Holocene activities of the He an Mountain piedmont fault on the basis of morphometric data of nickpoints and terraces along 45 gullies strentching across the mountain flank and of inclinations for various parts of the fault scarp.We have come to the conclusion that there were at least 8 events in the Holocene,the last one leading to an offset of the Great Wall 400 years ago and to nickpoints on the gullies,at a distance of about 5 m from the fault scarp.Under the condition that the last event for the fault was associated with Ping Luo earthquake of 1739 we may estimate the average rate of headward erosion for the gullies resulting from uplifting of the fault scarp to be 2.0-2.5cm/yr.Based on the distance between the two neighbouring nickpoints,the average rate mentioned above and the climate of China showing a tendance to have come drier and drier in the last 5000 years,we have worked out the cycles of activity for the Helan Mountain piedmont fault as shown in Table 3.From relative height for varios terraces near the fault scarp we have calculated the amplitude of movement of the fault occurring during each cycle (Table 4).

摘要： 本文根据穿过断层的45条冲沟中的裂点和阶地测量资料,论述贺兰山山前断层全新世以来的活动状况。我们认为全新世以来该断层至少有8次活动。最后一次断层活动错断了距今400年的长城,并在冲沟中形成一个裂点,该裂点现今已距断层陡坎约5米远。假定这次断层活动和1739年平罗大地震有关,求出裂点的溯源侵蚀平均速度为2.0-2.5厘米/年.根据两裂点间的距离和裂点的溯源侵蚀平均速度,并考虑到我国近5000年的气候有逐渐变干的趋势,求出断层活动的周期(表3)。从断层陡坎附近的各级阶地面之间的高差,求出断层各次活动的幅度(表4)。