Abstract: On the bases of technical study of tree ring dating,several hundreds of trees growing along the western part of Gulang active fault were determined and evaluated.The growing rates oftrees and the three types of lower ring ratios have been identified effectively. The results show that the abnormal ring structures and growing rate of the Qinghai cryptomeria fir on the fault scarp were caused by the Gulang M8.0 earthquake on May 23,1927,which gives exact evidence for the dating of Gulang seismogenic fault and moved the location of this fault along the northern foot of Lenglongling to the south by 30km. The research mentioned above has also been applied successfully to the dating of the fracture belt caused by the Jingtai M6¹/4 earthquake on Novem-ber 2,1888,along the northern foot active fault of Laohushan mountain.

Key words: Fault chorn, Active fault, Tree ring, Gansu

摘要： 在树木地震学测年技术研究的基础上,沿古浪活断层西段鉴定和评价了数百棵树。对树木生长速率及年轮比率低值偏离的3种类型进行了有效的识别。结果表明:断崖上被破坏的青海云杉中,记录的结构和生长速率异常,可以归因于1927年5月23日古浪8级大地震的影响。从而为古浪地震断层的判定提供了准确的年代证据。并将前人认为的古浪地震断层位置向冷龙岭北麓南移了30余公里。用该方法在老虎山活断层上对1888年11月2日景秦61/4级地震破裂带定年,再次获得成效。

关键词: 断层年代, 活断层, 树木年轮, 甘肃