ABSTRACT
The samples with compressional, extensional and complex en-echelon faults are deformed experimentally under biaxial compression, spatial and temporal distribution of acoustic emission, fault displacements and strain during deformation are studied. Compressional and extensional en-echelon faults have similar deformation process, i.e. deformation is predominated by fracturing and linking of jogs in the first stage and by sliding along faults in the second stage. However, high strain energy can be accumulated and strong acoustic emission could be produced in compressional jog, while in extensional jog, strong acoustic emission event can not be produced Deformation process of complex en-echelon faults is not a simple combination of that of two types of en-echelon faults, but contains interaction between them. An interesting phenomenon is that acoustic emission events with high energy occur mostly along main fault near extensional jog, not along fault near compressional jog, but the time of such event is controlled by the deformation process of compressive jog. Instability events with different characteristics could be observed in the experiments. Based on the results, possible relationship between enechelon faults and seismicity is discussed.
