The Australian Government's five year (2006-2011) Offshore Energy Security Program aims to encourage the discovery of new hydrocarbon resources in Australia's vast offshore frontier areas through the provision of pre-competitive data and information. One priority region, identified in consultation with the petroleum exploration industry and the respective State and Northern Territory geological surveys, is the southwestern continental margin of Australia. Geoscience Australia's Southwest Margin Project is investigating the petroleum potential of sedimentary basins located on the continental margin extending from Cape Range to Cape Leeuwin. Primary areas of interest include the Perth and Mentelle basins. Other areas of interest include the southern Exmouth Sub-basin (Northern Carnarvon Basin), the offshore Southern Carnarvon Basin and the Wallaby Plateau. The main aims of the Southwest Margin Project are to provide pre-competitive regional information to underpin opportunities for the discovery of a new hydrocarbon province, to support promotion of selected areas for petroleum exploration, to enhance our understanding of petroleum potential and aspects of exploration risk and to inform future marine planning. Citation: Bowen, E., & Bradshaw, B. (2009). Geoscience australia’s southwest margin geophysical surveys. ASEG Extended Abstracts, 2009(1), 1–7. https://doi.org/10.1071/ASEG2009ab018

The Australian Government's five year (2006-2011) Offshore Energy Security Program aims to encourage the discovery of new hydrocarbon resources in Australia's vast offshore frontier areas through the provision of pre-competitive data and information. One priority region, identified in consultation with the petroleum exploration industry and the respective State and Northern Territory geological surveys, is the southwestern continental margin of Australia. Geoscience Australia's Southwest Margin Project is investigating the petroleum potential of sedimentary basins located on the continental margin extending from Cape Range to Cape Leeuwin. Primary areas of interest include the Perth and Mentelle basins. Other areas of interest include the southern Exmouth Sub-basin (Northern Carnarvon Basin), the offshore Southern Carnarvon Basin and the Wallaby Plateau. The main aims of the Southwest Margin Project are to provide pre-competitive regional information to underpin opportunities for the discovery of a new hydrocarbon province, to support promotion of selected areas for petroleum exploration, to enhance our understanding of petroleum potential and aspects of exploration risk and to inform future marine planning. Citation: Bowen, E., & Bradshaw, B. (2009). Geoscience australia’s southwest margin geophysical surveys. ASEG Extended Abstracts, 2009(1), 1–7. https://doi.org/10.1071/ASEG2009ab018

The Australian Government's five year (2006-2011) Offshore Energy Security Program aims to encourage the discovery of new hydrocarbon resources in Australia's vast offshore frontier areas through the provision of pre-competitive data and information. One priority region, identified in consultation with the petroleum exploration industry and the respective State and Northern Territory geological surveys, is the southwestern continental margin of Australia. Geoscience Australia's Southwest Margin Project is investigating the petroleum potential of sedimentary basins located on the continental margin extending from Cape Range to Cape Leeuwin. Primary areas of interest include the Perth and Mentelle basins. Other areas of interest include the southern Exmouth Sub-basin (Northern Carnarvon Basin), the offshore Southern Carnarvon Basin and the Wallaby Plateau. The main aims of the Southwest Margin Project are to provide pre-competitive regional information to underpin opportunities for the discovery of a new hydrocarbon province, to support promotion of selected areas for petroleum exploration, to enhance our understanding of petroleum potential and aspects of exploration risk and to inform future marine planning. Citation: Bowen, E., & Bradshaw, B. (2009). Geoscience australia’s southwest margin geophysical surveys. ASEG Extended Abstracts, 2009(1), 1–7. https://doi.org/10.1071/ASEG2009ab018

The Australian Government's five year (2006-2011) Offshore Energy Security Program aims to encourage the discovery of new hydrocarbon resources in Australia's vast offshore frontier areas through the provision of pre-competitive data and information. One priority region, identified in consultation with the petroleum exploration industry and the respective State and Northern Territory geological surveys, is the southwestern continental margin of Australia. Geoscience Australia's Southwest Margin Project is investigating the petroleum potential of sedimentary basins located on the continental margin extending from Cape Range to Cape Leeuwin. Primary areas of interest include the Perth and Mentelle basins. Other areas of interest include the southern Exmouth Sub-basin (Northern Carnarvon Basin), the offshore Southern Carnarvon Basin and the Wallaby Plateau. The main aims of the Southwest Margin Project are to provide pre-competitive regional information to underpin opportunities for the discovery of a new hydrocarbon province, to support promotion of selected areas for petroleum exploration, to enhance our understanding of petroleum potential and aspects of exploration risk and to inform future marine planning. Citation: Bowen, E., & Bradshaw, B. (2009). Geoscience australia’s southwest margin geophysical surveys. ASEG Extended Abstracts, 2009(1), 1–7. https://doi.org/10.1071/ASEG2009ab018

The Australian Government's five year (2006-2011) Offshore Energy Security Program aims to encourage the discovery of new hydrocarbon resources in Australia's vast offshore frontier areas through the provision of pre-competitive data and information. One priority region, identified in consultation with the petroleum exploration industry and the respective State and Northern Territory geological surveys, is the southwestern continental margin of Australia. Geoscience Australia's Southwest Margin Project is investigating the petroleum potential of sedimentary basins located on the continental margin extending from Cape Range to Cape Leeuwin. Primary areas of interest include the Perth and Mentelle basins. Other areas of interest include the southern Exmouth Sub-basin (Northern Carnarvon Basin), the offshore Southern Carnarvon Basin and the Wallaby Plateau. The main aims of the Southwest Margin Project are to provide pre-competitive regional information to underpin opportunities for the discovery of a new hydrocarbon province, to support promotion of selected areas for petroleum exploration, to enhance our understanding of petroleum potential and aspects of exploration risk and to inform future marine planning. Citation: Bowen, E., & Bradshaw, B. (2009). Geoscience australia’s southwest margin geophysical surveys. ASEG Extended Abstracts, 2009(1), 1–7. https://doi.org/10.1071/ASEG2009ab018

The Capel and Faust Basins in Australia's remote eastern offshore frontier, 800 km east of Brisbane in 1000-3000 m of water, are being studied as part of the Australian Government's Energy Security Initiative. A variety of geophysical data has been obtained and efforts are currently focussed on integrated interpretation of 2D seismic reflection data, sonobuoy refraction data and marine potential-field data. Negative residual gravity anomalies generally correlate with basins evident in the seismic reflection data. The anomalies highlight elongate, roughly N-S-trending or arcuate depocentres, with limited strike extent, that are best developed in the north and northwest of the survey area where increased crustal extension appears to have occurred. The 20-50 km separation between 2D seismic lines and the isolated nature of the basin depocentres complicates the process of linking structures between lines, but 3D mapping of faults and horizons is facilitated by the potential-field data. Instead of correlating with depocentres and basement highs, reduced-to-pole positive magnetic anomalies may reflect the distribution of volcanics and intrusives, variably evident as high-amplitude or low-frequency reflectors, and volcanic features at or near the seafloor. Interpretation of the seismic reflection data suggests the presence of four main syn-rift megasequence packages (?Early Cretaceous-?Santonian) and several post-rift sag packages (?Early Campanian-Recent). Maximum unequivocal depocentre thickness is ~4s TWT. Forward and inverse modelling of the gravity and magnetic data in 3D is providing a means to characterise different basement terranes and to construct surfaces that represent the sequence boundaries within the depocentres.

The Capel and Faust Basins in Australia's remote eastern offshore frontier, 800 km east of Brisbane in 1000-3000 m of water, are being studied as part of the Australian Government's Energy Security Initiative. A variety of geophysical data has been obtained and efforts are currently focussed on integrated interpretation of 2D seismic reflection data, sonobuoy refraction data and marine potential-field data. Negative residual gravity anomalies generally correlate with basins evident in the seismic reflection data. The anomalies highlight elongate, roughly N-S-trending or arcuate depocentres, with limited strike extent, that are best developed in the north and northwest of the survey area where increased crustal extension appears to have occurred. The 20-50 km separation between 2D seismic lines and the isolated nature of the basin depocentres complicates the process of linking structures between lines, but 3D mapping of faults and horizons is facilitated by the potential-field data. Instead of correlating with depocentres and basement highs, reduced-to-pole positive magnetic anomalies may reflect the distribution of volcanics and intrusives, variably evident as high-amplitude or low-frequency reflectors, and volcanic features at or near the seafloor. Interpretation of the seismic reflection data suggests the presence of four main syn-rift megasequence packages (?Early Cretaceous-?Santonian) and several post-rift sag packages (?Early Campanian-Recent). Maximum unequivocal depocentre thickness is ~4s TWT. Forward and inverse modelling of the gravity and magnetic data in 3D is providing a means to characterise different basement terranes and to construct surfaces that represent the sequence boundaries within the depocentres.

The Capel and Faust Basins in Australia's remote eastern offshore frontier, 800 km east of Brisbane in 1000-3000 m of water, are being studied as part of the Australian Government's Energy Security Initiative. A variety of geophysical data has been obtained and efforts are currently focussed on integrated interpretation of 2D seismic reflection data, sonobuoy refraction data and marine potential-field data. Negative residual gravity anomalies generally correlate with basins evident in the seismic reflection data. The anomalies highlight elongate, roughly N-S-trending or arcuate depocentres, with limited strike extent, that are best developed in the north and northwest of the survey area where increased crustal extension appears to have occurred. The 20-50 km separation between 2D seismic lines and the isolated nature of the basin depocentres complicates the process of linking structures between lines, but 3D mapping of faults and horizons is facilitated by the potential-field data. Instead of correlating with depocentres and basement highs, reduced-to-pole positive magnetic anomalies may reflect the distribution of volcanics and intrusives, variably evident as high-amplitude or low-frequency reflectors, and volcanic features at or near the seafloor. Interpretation of the seismic reflection data suggests the presence of four main syn-rift megasequence packages (?Early Cretaceous-?Santonian) and several post-rift sag packages (?Early Campanian-Recent). Maximum unequivocal depocentre thickness is ~4s TWT. Forward and inverse modelling of the gravity and magnetic data in 3D is providing a means to characterise different basement terranes and to construct surfaces that represent the sequence boundaries within the depocentres.

The Capel and Faust Basins in Australia's remote eastern offshore frontier, 800 km east of Brisbane in 1000-3000 m of water, are being studied as part of the Australian Government's Energy Security Initiative. A variety of geophysical data has been obtained and efforts are currently focussed on integrated interpretation of 2D seismic reflection data, sonobuoy refraction data and marine potential-field data. Negative residual gravity anomalies generally correlate with basins evident in the seismic reflection data. The anomalies highlight elongate, roughly N-S-trending or arcuate depocentres, with limited strike extent, that are best developed in the north and northwest of the survey area where increased crustal extension appears to have occurred. The 20-50 km separation between 2D seismic lines and the isolated nature of the basin depocentres complicates the process of linking structures between lines, but 3D mapping of faults and horizons is facilitated by the potential-field data. Instead of correlating with depocentres and basement highs, reduced-to-pole positive magnetic anomalies may reflect the distribution of volcanics and intrusives, variably evident as high-amplitude or low-frequency reflectors, and volcanic features at or near the seafloor. Interpretation of the seismic reflection data suggests the presence of four main syn-rift megasequence packages (?Early Cretaceous-?Santonian) and several post-rift sag packages (?Early Campanian-Recent). Maximum unequivocal depocentre thickness is ~4s TWT. Forward and inverse modelling of the gravity and magnetic data in 3D is providing a means to characterise different basement terranes and to construct surfaces that represent the sequence boundaries within the depocentres.

Many of the onshore sedimentary basins in Australia are underexplored with respect to hydrocarbons. The Onshore Energy Security Program was funded by the Australian Government over five years (2006-2011) for Geoscience Australia to provide precompetitive geoscience data and assessments of the potential of some frontier onshore sedimentary basins for energy resources, including hydrocarbons, uranium, thorium and geothermal energy. The basins studied in this project include the Burke River Structural Zone of the Georgina Basin (northwest Queensland), the Yathong Trough in the eastern Darling Basin (western New South Wales), and the Arrowie Basin (South Australia). The interpretation of deep seismic reflection profiles and petroleum systems maturation modelling was undertaken in these basins to increase the understanding of their petroleum potential. The Arrowie Basin seismic data shows an asymmetrical basin architecture, with the basin fill being ~3800 m at its thickest. Several sequence boundaries are mapped in this seismic section, and are correlated with the sequence boundaries between the major Neoproterozoic stratigraphic groups in the Adelaide Rift System. In the easternmost part of the seismic section, a series of east-dipping thrust faults disrupt the stratigraphic section. The petroleum systems maturation modelling shows that potential Cambrian source rocks are likely immature to mature for oil generation. In contrast, potential Neoproterozoic source rocks are likely to be mature to overmature for oil generation, and immature to mature for gas generation. With hydrocarbon systems clearly present in the Arrowie Basin as shown by bitumen in shallow exploration wells drilled in the 1950's, future work, possibly with a focus on unconventional hydrocarbons, would be warranted. The Burke River Structural Zone of the Georgina Basin seismic data shows the basin is ~65 km wide, with a half-graben geometry, being bounded in the west by a rift border fault. The succession in the basin has a maximum thickness of ~2800 m, with the stratigraphy being relatively flat lying, and thickening towards the west. The petroleum systems maturation modelling shows potential Cambrian source rocks are likely to be oil mature. Significant generation and expulsion probably occurred early in the burial history, in response to Cambrian-Ordovician loading. Expulsion occurred after trap formation in the Neoproterozoic-Cambrian, but before later trap formation in the Devonian. The required long preservation time and unroofing are the major risk factors within the basin. The Yathong Trough of the Darling Basin seismic data interpretation shows that the basin fill consists of a thick succession characterised by alternating high and low amplitude seismic reflections, interpreted to represent the expected Devonian succession mudstones and sandstones. The basement units below the Yathong Trough are interpreted to be Ordovician turbidites and Ordovician-Silurian granites, considered to be part of the Lachlan Orogen. The petroleum systems maturation modelling shows that potential Lower and Middle Devonian source rocks are likely to be overmature for oil generation and mature for gas generation. Generation and expulsion from Lower and Middle Devonian potential marine source rocks occurred early during their burial history, prior to Carboniferous uplift and erosion, and thus, major trap formation. Later burial during the Permian and/or Cretaceous may have resulted in minor gas generation and expulsion from a Middle Devonian potential source rock.