【摘要】 通过大探槽开挖和断层陡坎分析，揭示出发生于１６７９年８级地震的新夏垫断层自距今约２万ａ以来共发生了４次地震事件。前两次为砂体液化显示的事件；后两次为可见直接断错证据的事件。分析得到的１６７９年地震最大垂直位移为１．７５ｍ，前１６７９年事件为１．４１ｍ，是两次震级非常接近的特征地震。４次事件发生的时间分别为距今约２００００，１３０００，７５００和３１７ａ，平均重复间隔时间为（６５６１±６９１）ａ，显示了准周期重复的特征。更多还原

【Abstract】 The 4 paleoearthquake events that have occurred on seismogenic fault of 1679 Sanhe Pinggu M 8 Earthquake since 20ka B.P. are exposed through the analysis of trenches and fault scarp profiles. The earlier two events are marked by liquefaction and the later two events are shown by direct fault offset, including the 1679 event. The 1679 event and pre 1679 event are two characteristic earthquakes of which the maximum displacement is about 1.75m and 1.41m, respectively and the intensity of two events is very close. The occurrence time of 4 events was about 20 000, 13 000, 7 500 and 317a B.P., respectively. Average interval of recurrence is (6 561±691)a. It indicates the characteristics of quasi periodic occurrence of earthquakes.更多还原