Incrementally developed slickenfibers - Geological record of repeating low stress-drop seismic events?

An accretionary melange of Triassic age ocean floor sediments exposed in the Chrystalls Beach Complex, South Island, New Zealand, comprises competent sandstone and chert phacoids set in a cleaved mudstone matrix, deformed in a continuous-discontinuous style at subgreenschist conditions. Deformation structures include a pervasive anastomosing fault-fracture mesh of multiple shearing surfaces, subparallel to cleavage, coated with incrementally developed quartz-calcite slickenfibers. Microstructural observations reveal slickenfiber growth by 'crack-seal' shear slip increments of 10-100 mu m, with incremental slip transfer of the same order accommodated by opening of extension fractures that link en echelon slip surfaces. Individual slip surfaces can be traced for meters to tens of meters so that the ratio of average slip, u, to potential rupture length. L, predominantly lies within the range, 10(-6)