The Subsidence And Thermal History Of The Bass Basin, Southeastern Australia
Journal Article: The Subsidence And Thermal History Of The Bass Basin, Southeastern Australia
AbstractThe Bass Basin, located offshore between mainland Australia and Tasmania, contains an unknown thickness of continental sediments of Cretaceous and Lower Paleocene age overlain by up to 3 km of Eocene to Recent marine sediments. It has been postulated that the basin resulted from tensional stress due to the relative movement of mainland Australia and Tasmania. Stratigraphic data from petroleum exploration wells indicate a basin subsidence in Tertiary times proportional to the square root of time after beginning of subsidence (). Early and Middle Tertiary subsidence appears to have occurred under block-wise isostatic compensation. Geothermal gradients in the basin are typically 35°C km-1. Three mechanisms of subsidence: 1. (a) thermal contraction of the lithosphere 2. (b) stretching of the lithosphere 3. (c) deep crustal metamorphism are discussed in relation to the formation of the basin. Mechanisms (a) and (c) produce subsidence proportional to , and mechanism (b) approximates this condition. The deep crustal metamorphism mechanism is most consistent with observed subsidence, thermal history and depositional environments.
- M. F. Middleton
- Published Journal
- Tectonophysics, 1982
M. F. Middleton. 1982. The Subsidence And Thermal History Of The Bass Basin, Southeastern Australia. Tectonophysics. (!) .