Advanced burial and thermal geo-history modelling was carried out using Fobos Pro modelling software for the first time in Australia without relying on default or inferred values (such as heat flow or geothermal gradient). Our methodology is a substantial extension to the conventional approach.

The interpretation of two regional seismic reflection profiles and the construction of a balanced cross section through the southern Australian margin (Bight Basin) are designed to analyze the influence of the Australia-Antarctica continental breakup process on the kinematic evolution of the Cretaceous Ceduna delta system. The data shows that the structural architecture of this delta system consists of two stacked sub-delta systems. The lower White Pointer delta system (Late Albian-Santonian) is an unstable tectonic wedge, regionally detached seaward above Late Albian ductile shales. Sequential restorations suggest that the overall gravitational sliding behavior of the White Pointer delta wedge (~45 km of seaward extension, i.e., ~25%) is partially balanced by the tectonic denudation of the subcontinental mantle. We are able to estimate the horizontal stretching rate of the mantle exhumation between ~2 km Ma-1and 5 km Ma-1. The associated uplift of the distal part of the margin and associated flexural subsidence in the proximal part of the basin are partially responsible for the decrease of the gravitational sliding of the White Pointer delta system. Lithospheric failure occurs at ~84 Ma through the rapid exhumation of the mantle. The upper Hammerhead delta system (Late Santonian-Maastrichtian) forms a stable tectonic wedge developed during initial, slow seafloor spreading and sag basin evolution of the Australian side margin. Lateral variation of basin slope (related to the geometry of the underlying White Pointer delta wedge) is associated with distal raft tectonic structures sustained by high sedimentation rates. Finally, we propose a conceptual low-angle detachment fault model for the evolution of the Australian-Antarctica conjugate margins, in which the Antarctica margin corresponds to the upper plate and the Australian margin to the lower plate.

In 2009, as part of its Onshore Energy Security Program, Geoscience Australia, in conjunction with the Northern Territory Geological Survey, acquired 373 km of vibroseis-source, deep seismic reflection, magnetotelluric and gravity data along a single north-south traverse from the Todd River in the south to nearly 30 km north of the Sandover Highway in the north. This traverse, 09GA-GA1, is referred to as the Georgina-Arunta seismic line, extends from the northeastern Amadeus Basin, across the Casey Inlier, Irindina and Aileron provinces of the Arunta Region and Georgina Basin to the southernmost Davenport Province. Here, we report the results of an initial geological interpretation of the seismic and magnetotelluric data, and discuss some preliminary geodynamic implications.

No abstract available

The Bland Basin is the broad alluviated palaeovalley of Bland Creek, a tributary of the Lachlan River in the central part of New South Wales, Australia, within the drainage basin of the Murray-Darling River System. It covers about 4000 km2 and contains up to 120 m of terrestrial sediments, interpreted as being deposited by alluvial, colluvial, lacustrine/paludal, and aeolian processes. It is undated, but is likely to be coeval with the downstream contiguous fill of the Lachlan River palaeovalley, dated elsewhere by palynology as Miocene to Recent. The southwestern part of the basin has been studied in detail using airborne geophysics (electromagnetics, magnetics, and gamma ray spectrometry) and drilling. The small erosional catchment area of the modern Basin surface has resulted in a paucity of sediment available for deposition in the Basin, but drainage base level has been driven by the rate of sedimentation of the Lachlan palaeovalley downstream of the Basin. Therefore, most of the sediment derived from the catchment has been trapped in the Basin rather than being transported downstream and into the Lachlan palaeovalley, and at times large lakes and/or swamps have formed in the central part of the Basin. The sediments in the southwest of the Basin are dominated by clay and silt, with local sand and gravel, mostly in basal gravelly sand and a sandier interval in the middle part of the sequence. Quartz silt derived from aeolian dust is a major component of the upper part of the sedimentary sequence. Geophysical responses of the sediment include high conductivity due to saline groundwater, low gamma response dominated by thorium decay emissions due to the leached nature of the sediment, and short wavelength-low amplitude magnetic anomalies resulting from local concentrations of detrital maghemite-rich gravel formed during weathering in the catchment area. Other broad valleys draining to the Lachlan River may contain similar mud-dominated Neogene basins.

In 2006, deep seismic reflection profiling was carried out along six transects across the Mount Isa Inlier. The seismic lines were jointly funded by the Geological Survey of Queensland, Geoscience Australia, the Predictive Mineral Discovery Cooperative Research Centre and Zinifex Pty Ltd. (now Oz Minerals). In 2007, a further three seismic lines were collected by Geoscience Australia and the Geological Survey of Queensland from Cloncurry to south of Charters Towers via Croydon and Georgetown. This paper presents some highlights from the geological interpretations of the seismic lines.

This report was Commissioned by Geoscience Australia for the Western Tasmania Regional Minerals Program (WTRMP). It was completed by SRK Consulting, and is listed as Report AG701. The report covers the interpretation of economic basement in the Bass Basin, and documents the production of a SEEBASE model.

Legacy product - no abstract available

This report contains data on the 68 petroleum accumulations discovered in the Bonaparte Basin to December 2002. It provides summaries of the regional setting, evolution and stratigraphy of the basin and discusses the hydrocarbon habitat and development of the producing accumulations. For the purpose of this report, a discrete, measured recovery of petroleum on test from an exploration well qualifies as a `discovery?. Petroleum accumulations inferred from wireline log interpretations (and where petroleum has not been recovered on test) are referred to as `shows?. Small quantities of gas recovered on test in three wells included in this report may represent `solution gas? - indicating these wells may not have intersected a petroleum pool.

Legacy product - no abstract available