Australia's east coast north of Bass Strait has been very sparsely explored for petroleum. Exploration permits have been intermittently held over the offshore Sydney Basin, including an active permit at the time of writing, and some permits were held in north Queensland waters in the 1960s and 1970s, but much of the geology of this eastern continental margin is virtually unknown. This report provides a preliminary assessment of the petroleum potential of Australia's east coast, from the border between New South Wales and Victoria in the south, to the southern boundary of the Great Barrier Reef Marine Park (GBRMP) offshore southeast Queensland in the north. Petroleum exploration is prohibited within the GBRMP, and no assessment of this area is included in the report.
Palaeozoic basement rocks covered by a veneer of Cainozoic sediments underlie a large part of the study area (Figure 1). At least four sedimentary basins also underlie the continental shelf and probably the continental slope in the case of the Sydney and Maryborough Basins. These two basins are also the best known; but the Clarence-Moreton and Nambour Basins are also known to have offshore extensions on the shelf. It is also possible but not certain that the Ipswich and Lorne Basins could have offshore components, and there is some evidence of a pre-Clarence-Moreton Basin sedimentary sequence offshore of the Coffs Harbour area. In addition to these basins, several graben and half-graben associated with Tasman Sea rifting may occur within basement dominated shelf and slope areas - two of these features are known from very limited data.