Structure of the Permian-Mesozoic Eastern Australian Basins Complex, With Emphasis on the BMR Bowen Basin Deep Seismic Profiles

Abstract

The geometries of sedimentary basins in eastern Australia, observed in BMR seismic data, place constraints on models for their development. The Permian Taroom Trough (southern, subsurface extension of the Bowen Basin) is interpreted as a transtensional basin associated with strike-slip faulting. Small flower structures in overlying Jurassic sediments are interpreted as transpressional features due to reactivation of the faults. To the north, the BMR Bowen Basin deep seismic data show a Late Permian-Early Triassic sedimentary wedge that appears to thicken to the east, suggesting a similar geometry to that seen in the Taroom Trough. The sedimentary section is deformed by a series of listric thrust faults that root in a major east-dipping detachment which appears to flatten in the middle crust. Thus, the exposed part of the Bowen Basin possibly was initiated during a period of extension oriented ENE-WSW in the latest Carboniferous or earliest Permian, whereas to the south, the subsurface part of the basin was dominated by oblique extension and strike-slip (transtension).