The geometry, kinematics, and reactivation history of major fault systems in eastern Australia: implications for deformation phases from the Permian to Cenozoic

Abstract

Eastern Australia has been affected by numerous fault systems, but their pattern, geometry, kinematics, and timing have hitherto remained relatively understudied. This thesis makes an effort to address this issue by investigating fault systems and their reactivation history. The results of this thesis shed new light on the tectonic history of eastern Australia since the Permian. The aim of this work is to unravel the role of major faults in the tectonic evolution of eastern Australia by studying geometry and kinematics of fault systems during the early Permian, Triassic to Jurassic, and late Mesozoic to Cenozoic. The NNW-striking North Pine Fault System (NPFS) has been studied. The NPFS has undergone sinistral reverse strike-slip movement with offsets ranging from ~3.4 to ~8.2 km. Based on a Triassic IV granophyre dyke parallel to the southeastern NPFS, and the contribution of parallel NNW-striking strike-slip and normal faults in the development of the Late Triassic-Early Cretaceous Maryborough Basin, the NPFS has likely been active during the Mesozoic. The NPFS is interpreted to have been reactivated with oblique sinistral-normal kinematics during the Late Cretaceous-early Eocene in response to regional oblique extension associated with the opening of the Tasman and Coral seas.The recent strike-slip reverse movement was likely due to far-field contractional stresses from collisional tectonics at the eastern and northern boundaries of the Australian plate in the Cenozoic.