Multistage deformation of linked fault systems in extensional regions: an example from the northern Perth Basin, Western Australia

Linked fault systems identified in the northern portion of the onshore Pert h basin comprise north-striking normal faults, the dominant structures in t he basin, and hard linkages-east-striking transfer faults. The former are e ither divided into segments of distinctive character by, or terminate at, t he transfer faults. The fault systems were initiated by west-southwest-east -northeast extension in the Early Permian but were reactivated by subsequen t rifting with approximately east-west extension in the Jurassic, They were also reactivated by the oblique extension of northwest-southeast orientati on associated with Gondwana continental breakup in the Late Jurassic-earlie st Cretaceous. In addition to reactivation, older structures of the linked fault families controlled the development of younger fractures and folds. D uring the oblique extension, the linked fault systems define releasing bend s, characterised by a rollover anticline in the hangingwall of the Mountain Bridge Fault, and restraining bends where contractional folds are sites of major commercial hydrocarbon fields in the basin.