Striations on minor faults and the structure of the Parmeener Super-group near Hobart, Tasmania

Abstract

Fault striations were measured on 104 minor faults within the Parmeener Super-group near Hobart. The fault striations probably reflect the complex movement history on adjacent large faults. Sophisticated numerical modelling of the regional stress systems which produced these striations indicated at least two phases of faulting. The earlier phase was probably due to compression from the NNW in the Mesozoic and produced strike slip faults striking 1000 and 1700C. The later phase of faulting was caused by extension towards the ENE in the Early to Middle Tertiary and reactivated most of the early phase faults striking 1700 , as normal dip slip faults. A small number of fault striations could not be attributed to either of these events.