Abstract
Using wet kaolin experiments, we document the evolution of strain localization during strike-slip fault maturation under variable boundary conditions (pre-existing fault, depth of and distribution of basal shear). While the nature of the basal shear influences strain localization observed at the clay surface, similarities between experiments reveal a general conceptual model of strain accommodation. First, shear strain is accommodated as distributed shear (Stage 0), then by development of echelon faults (Stage I), then by interaction, lengthening and propagation of those echelon faults (Stage II) and, finally, by slip along through-going fault (Stage III). Stage II serves as a transitory period when the system reorganizes after sufficient strain localization. Here, active fault system complexity is maximized as faults link producing apparent rotation of active fault surfaces without material rotation. As the shear zone narrows, off-fault deformation decreases while fault slip and kinematic efficiency increases. We quantify kinematic efficiency as the ratio of fault slip to applied displacement. All fault systems reach a steady-state efficiency in excess of 80%. Despite reducing off-fault deformation, the through-going fault maintains <1.5 cm structural irregularities (i.e., stepovers), which suggests that small (<3 km) stepovers may persist along mature, efficient faults in the crust.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.