关键词: 失稳振荡, 断层面形迹, 异常构造

Abstract: The experimental study on transient processes of fracture and stick-stip instability shows that both of the stress drop and the displacement rise are not monotonous.They are oscillatory ones with multifrequencies.The SEM observation on fracture surfaces shows that the oscillation led to bilateral or multilateral traces.By combining the experimental results with the phenomena observed from natural fault surface and fault zone,such as slickensides,grooving,steps and abnormal array of subfaults,it has been presented that one of the reasons for the traces which reflect the bilateral or multilateral motions of natural fault may be the instability oscillation of fault from an event (earthquake).In contrast,these phenomena may be indicators as ancient earthquakes.

Key words: Instability osillation, Faulting trace, Abnormal array of subfaults