通过卫星影像解译、野外实地调查和地质填图,对滇西南地区的澜沧断裂的最新活动性开展了翔实的调查,重点对该断裂的古地震特征进行了分析,通过中南段3个探槽剖面的详细分析和样品年代测试,对其存在的古地震事件进行了判定,初步确定了6次古地震事件的发生年代,分别为距今约3700a、2300-2500a、1200-2000a、900-1200a、500-600a和20a。古地震具有周期复发的特征,其复发间隔为500-600a。
According to satellite image interpretation, field investigation and geological mapping, we investigated the latest activity of Lancang Fault which is located in the southwestern area of Yunnan. On the basis of characteris- tic of the latest activity of Lancang Fault, we focus on analyzing the characteristic of the paleoearthquakes on the fault. After analyzing the three trench profile in detail on the middle south segment of the fault and the testing of the sample dating, we primarily determined that the occurrence time of six paleoearthquakes was about 3700 a, 2300-2500 a, 900-1 200 a, 1 200-2 000 a, 500-600 a, and 20 a ago respectively. The paleoearth- quakes had the characteristics of periodic recurrence, and the recurrence interval is 500 -600 a.