The investigation of the Fitzroy Basin and adjacent areas was commenced in 1948 when a detailed survey was made of the Nerrima Structure and a widespread reconnaissance by land, sea and air was completed. The Fitzroy Basin survey was completed in 1952 and during this period 24 months were spent in the field and the remainder in office preparation. Approximately 40,000 square miles were examined during the survey and detailed maps covering an area of 28,000 square miles have been prepared at 1 inch = 1 miles, 1 inch = 2 miles and 1 inch = 10 miles. The area has been examined in the past in varying detail by three geological parties on behalf of local and overseas oil companies. The purpose of this survey was to examine the complete sedimentary sequence in sufficient detail to solve the problems encountered by previous surveys and eventually to be in a position to assess to a reliable degree the petroleum prospects of the area based on the examination of surface outcrop. The assessment of the petroleum prospects of the area has very definite limitations in that the potential source rocks (Devonian and Ordovician) are limited to the extreme eastern margin of the basin and nothing is known about their distribution or facies elsewhere under the cover of Permian and Mesozoic sediments. The aerial photography of the area, which was conducted by the Survey Squadron of the Royal Australian Air Force, has been the basis of all mapping, as reliable topographic maps of the area were not available.

No abstract available

Geoscience Australia's Bremer Sub-basin Study is providing the first new frontier exploration opportunity under the Commonwealth Government's New Oil program.

Geodynamic modelling of selected aspects of the Bowen, Gunnedah, Surat and Eromanga basins constrains the mechanisms that were operating during their formation. For the Bowen and Gunnedah basins, a quantitative analysis of the early Late Permian to Middle Triassic foreland loading phase examined the relative roles of static loading versus dynamic loading associated with the convergent plate margin. Subsidence in the initial foreland phase in the early Late Permian is consistent with platform tilting due to corner flow in the mantle associated with west-directed subduction. Later in the Late Permian, platform tilting probably continued to be the dominant cause of subsidence, but increasing amounts of subsidence due to foreland loading occurred as the thrust front in the New England Orogen migrated westward. In the latest Permian and Early Triassic, static flexural loading due to foreland loads is dominant and may be the sole cause for basin subsidence. For the Surat and Eromanga basins, the tectonic subsidence across an east-west transect is modelled to assess the contribution of dynamically-induced platform tilting, due to viscous mantle corner flow, in basin subsidence. The modelling suggests that subsidence was again controlled by dynamic platform tilting, which provides a mechanism for both the nearfield and farfield effects. Uplift of the Eastern Highlands in the mid-Cretaceous may also be related to viscous corner flow driven by west-directed subduction beneath eastern Australia, with the uplift being due to rebound of the lithosphere after the cessation of subduction.

New 2D seismic data acquired in the Mentelle Basin by Geoscience Australia in 2008-09 has been used for a seismic facies study of the post-rift succession. The Mentelle Basin is a large deep to ultra deep-water, frontier basin located on Australia's southwestern margin about 200 km southwest of Perth. The study focused on the post-rift sequences deposited following the breakup between Australia and Greater India. Stratigraphic wells DSDP 258 and DSDP 264 provide age and lithological constraints on the upper portion of the post-rift succession down to mid-Albian strata. The depositional environment and lithology of the older sequences are based on analysis of the seismic facies, stratal geometries and comparisons to the age equivalent units in the south Perth Basin. Fourteen seismic facies were identified based on reflection continuity, amplitude and frequency, internal reflection configuration and external geometries. They range from high continuity, high amplitude, parallel sheet facies to low continuity, low amplitude, parallel, subparallel and chaotic sheet, wedge and basin-fill facies. Channel and channel-fill features are common in several facies as well as a mounded facies (probably contourite) and its associated ponded turbidite fill. A progradational sigmoidal to oblique wedge facies occurs at several stratigraphic levels in the section. A chaotic mound facies, probably comprising debrite deposits, has a localised distribution. Seismic facies analysis of the post-rift sequences in the Mentelle Basin has contributed to a better understanding of the depositional history and sedimentation processes in the region, as well as provided additional constraints on regional and local tectonic events.

Petroleum exploration on the Exmouth Plateau has ceased, althoughthe giant Scarborough Gas Field has been retained by Esso-BHP.Research cruises by BMR's vessel "Rig Seismic" and the associated assessment of other data, indicate that the plateau still has petroleumpotential, but the combination of deep water and low oil pricesmilitates against further exploration at present. However, the Ocean Drilling Program (ODP) core drilling on theWombat Plateau, in the far north of the Exmouth Plateau area, showedthat Rhaetian (Latest Triassic) reefs are present there, one beingdrilled at Site 764 (Fig. 1). This discovery was the first of aTriassic reef in Australia, and indicates that suitable conditions forreefal development are likely to be widespread on the Northwest Shelf.The existence of Late Triassic reef complexes suggests a new petroleumexploration play, with the reefs forming traps, and lagoonal faciesperhaps providing oil source potential. BMR has recently suggestedthat there is a 50% chance of Triassic reefs hosting 60 million barrelsof undiscovered oil on the Northwest Shelf. BMR's Marine Division intends to assess the potential of suchreefs and other known Triassic and Jurassic shelf carbonates in twophases. The first is to map the known reef complexes on the WombatPlateau, and to see how far they can be extended along the northernmargin of the Exmouth Plateau and into the Canning Basin. The secondis to take our knowledge of their seismic character, and the bestseismic parameters for mapping them, into the outer Bonaparte Basinwhere Triassic carbonate sequences up to 1000 m thick have beendrilled, but no reefs have yet been identified. The present project makes up the first phase of work, on thenorthern Exmouth Plateau. It is proposed that a 34 day cruise of "RigSeismic" be carried out in early 1990. This cruise should result inthe acquisition of 2500 km of multichannel seismic profiles on thenorthern Exmouth Plateau, about 15 dredges aimed at Triassic andJurassic carbonates, and up to 5 cores. The cruise and its post-cruisefollow-up work aim to (i)Map the extent of and facies changes within the Triassic/Jurassic carbonates in and south of Wombat Plateau, andin the Rowley Sub-basin of the southwestern Canning Basin, usingseismic profiling and dredging techniques. (ii)Define the extent, character and petroleum potential of any Triassic or Jurassic reefs found. (iii)Use the cruise results, along with other data, to help assessthe petroleum prospects of Mesozoic reef plays elsewhere on theNorthwest Shelf. (iv)Better define the geological history of the northern Exmouth Plateau and the adjacent southwest Canning Basin.

Legacy product - no abstract available

Abstract for initial submission; see Geocat 71429 for conference paper version

The Onshore Energy Security Program, funded by the Australian Government and conducted by Geoscience Australia, has acquired deep seismic reflection data across several frontier sedimentary basins to stimulate petroleum exploration in onshore Australia. Interpretation of the new seismic data from these onshore basins, focusing on overall basin geometry, internal sequence stratigraphy and petroleum potential, will be presented here. At the southern end of the exposed part of the Mt Isa Province, northwest Queensland, a deep seismic line (06GA-M6) crossed the Burke River Structural Zone of the Georgina Basin. The basin here is >50 km wide, with a half graben geometry, bounded in the west by a rift border fault. The Millungera Basin in northwest Queensland is completely covered by the Eromanga-Carpentaria Basin and was unknown prior to relatively short segments across the western part of the basin being imaged seismically in two lines (06GA-M4 and 06GA-M5) in 2006. Following this, seismic line 07GA-IG1 imaged a 65 km wide section of the basin. The geometry of internal stratigraphic sequences and a post-depositional thrust margin indicate that the original succession was much thicker than preserved today and there is potential for a petroleum system to exist. The Yathong Trough, in the southeast part of the Darling Basin in NSW, has been imaged in seismic line 08GA-RS2, with several stratigraphic sequences being mapped. Previous studies indicate that the upper part of this basin consists of Devonian sedimentary rocks, with potential source rocks at depth. In eastern South Australia, seismic line 08GA-A1 crossed the Cambrian Arrowie Basin, which is underlain by a Neoproterozoic succession of the Adelaide Rift System. Shallow drillholes have aided the assessment of the petroleum potential of the Cambrian Hawker Group, which contains bitumen in some of the cores, indicating the presence of source rocks in the basin system.

This dataset is a pre-release copy of the Australian Geological Provinces Database. The dataset is the best available national coverage of geological provinces as at 1 November 2012. The dataset is not entirely complete for the whole of Australia, and has not undergone complete and rigorous QA/QC. This interim dataset is provided for use only by Geoscience Australia staff and their approved collaborators. The Australian Geological Provinces Database contains descriptions and polygon outlines of geological provinces of the Australian continent and the surrounding marine jurisdictional area. Province types include sedimentary basins, basement tectonic provinces, igneous provinces, and metallogenic provinces. Descriptive attributes include sedimentary, igneous and structural characteristics, age limits, parent and constituent units, relations to surrounding provinces, and mineral and petroleum resources. The province outlines are typically compiled from source data at around 1:1,000,000 scale, which may include outcrop mapping, drilling, and geophysical data. Province boundaries have a spatial accuracy of around 500 metres at best (ie, where constrained by outcrop), but where province boundaries are concealed and are interpreted only from geophysical or drilling data, spatial accuracy may be in the order of 1 km to greater than 10 km. Attribution of province boundaries with information about data source and accuracy is incomplete in this version of the dataset.