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The paper discusses the results from the GA-302 2D seismic survey and GA-2436 (RV Tangaroa) marine reconnaissance survey over the Capel and Faust basins, northern Tasman Sea. The integration of seismic, potential field and bathymetric data sets in 3D space at an early stage in the project workflow has assisted in the visualisation of the basin architecture, the interpolation of data between the seismic lines, and the iterative refinement of interpretations. The data sets confirm the presence of multiple depocentres, as previously interpreted from satellite gravity data, with a maximum sediment thickness of 5-7 km. Preliminary interpretation of the seismic data has identified two predominantly Cretaceous syn-rift and two Upper Cretaceous to Neogene sag megasequences overlying a heterogeneous pre-rift basement. The comparison of seismic facies and tectonostratigraphic history with offshore New Zealand and eastern Australian basins suggests the presence of possible Jurassic to Upper Cretaceous coaly and lacustrine source rocks in the pre- and syn-rift, and fluvio-deltaic to shallow marine reservoir rocks in the syn-rift to early post-rift successions. Preliminary 1D basin modelling suggests that the deeper depocentres of the Capel and Faust basins are within the oil and gas windows. Large potential stratigraphic and structural traps are also present.

A comprehensive depth to magnetic basement map has been produced for the Gawler-Curnamona region of South Australia. The map combines depth to magnetic source estimates with outcrop, drill hole and seismic data. The spectral domain method of analysing the slope of straight line segments in the power spectrum was utilised to produce the majority of the magnetic source depth estimates. The spectral domain method was incorporated into a semi-automated in house software to rapidly produce the regional scale map. The map delineates large areas of prospective Gawler Craton and Curnamona Province basement beneath less than 300 m of cover material providing a useful tool for the mineral explorer. The map also delineates large areas under thick sequences of sediments, greater than 1000 m, which may prove of interest for the hydrocarbon explorer or act as a thermal blanket for the geothermal explorer.

This depth to basement point data set consists of a compilation depth values (meters below the topography) of basement geology buried beneath younger flat-lying cover material. The depth values are sourced from drill hole data, magnetic depth estimates and seismic refraction data. Drill hole data was compiled from a number of sources and consists of holes that entered basement only. The data consists of: - Mineral, Stratigraphic and Coal drill holes sourced from the Queensland Department of Mines and Energy's Interactive Resource and Tenure Maps system (http://www.dme.qld.gov.au/mines/tenure_maps.cfm) - Drill holes included with a GIS of the North Queensland Gold and Base Metals Study (Georgetown) sourced from the Queensland Department of Mines and Energy web site (http://www.dme.qld.gov.au/mines/seqgis.cfm#Georgetown) - Drill holes from the North-West Queensland Mineral Province Report. Seismic data depth estimates were generated from refracted first break seismic data for the North Queensland seismic lines 06GA-M4, 06GA-M5 and 07GA-IG1. Magnetic depth estimates were sourced from the following: - Magnetic depth determinations from the North-West Queensland Mineral Province Report. - Estimated depths to magnetic basement Springvale and Boulia 1:250 000 sheet areas. - Depth to magnetic source estimates from airborne magnetic profile data using the Naudy method. - Depth estimates from forward modelled profiles extracted from a magnetic grid using a dipping dyke as the source body.

New and existing Sm-Nd whole rock isotope data and U-Pb zircon ages from sedimentary rocks in several Australian Proterozoic Provinces hosting Zn-Pb mineralisation show a distinct transition that corresponds to a change from evolved sediment sources to more juvenile sedimentary sources at ~1650 Ma. This Sm-Nd isotopic change has been documented in the Eastern and Western Successions of the Mount Isa Inlier, the Etheridge Province of the Georgetown Inlier. A similar transition at ~1650 Ma has also been documented in the Broken Hill and Olary Domains of the Curnamona Province (Barovich and Hand 2008) and defines a continental-scale isotopic signal. The world-class, sediment-hosted Mt Isa and Hilton-George Fisher Zn-Pb Mt Isa-style deposits in the Western Mount Isa Inlier occur above the transition in sediments derived from more juvenile sources. In contrast, Pb-Zn-Ag Broken Hill-style deposits, including the Broken Hill (Curnamona), Cannington (Isa), Mount Misery (now Chloe) and Railway Flat deposits (Georgetown Inlier) (Carr et al. 2004) occur below this ~1650 Ma transition in sediments which have a much more evolved source.

The Laverton region, located in the Eastern Goldfields Superterrane (EGST), is second only to the Kalgoorlie region for gold endowment. The integration of high density potential field data, regional- and camp-scale seismic reflection data, regional- and mine-scale structural analysis, and geochronologically constrained stratigraphy, provided new insights into the 4D architecture and tectonic evolution of Laverton region.

Detrital zircon age spectra are widely used to determine the provenance of sedimentary successions and, in conjunction with tectonostratigraphic constraints, to make regional correlations and constrain tectonic settings of deposition. In the North Australian Craton Paleoproterozoic successions typically have detrital zircon patterns characterized by c. 1860 Ma and c. 2500 Ma detritus, potential sources of which are known from within the Craton. Detrital zircon patterns for the Cahill Formation and Nourlangie Schist, presented here, are distinctly different. These rocks comprise the bulk of the Paleoproterozoic strata in the Nimbuwah Domain, the easternmost part of the Pine Creek Orogen on the northern margin of the North Australian Craton. They comprise micaceous and quartzofeldspathic schist, carbonaceous schist, calc-silicate rock, amphibolite and quartzite. The Cahill Formation and Nourlangie Schist were deformed and metamorphosed during emplacement of the voluminous granitic to dioritic Nimbuwah Complex at 1867-1857 Ma. The Cahill Formation hosts several world-class uranium deposits including Ranger, Jabiluka and Nabarlek. U-Pb SHRIMP and LA-SF-ICPMS detrital zircon spectra for four samples of the Cahill Formation and six of the Nourlangie Schist show a similar broad spectrum of ages mainly in the range 3300-1900 Ma. An ubiquitous dominant peak at 2530-2470 Ma matches the age of underlying Neoarchean basement, from which it is probably sourced. Hf and O data from the detrital zircon of this age indicate this comprises mixed mantle-derived and supracrustal sources. Common smaller peaks occur at 2180 Ma, 2080 Ma and 2020 Ma. The former two have no known magmatic age correlatives in the North Australian Craton. The latter have distinct, strongly unradiogenic zircon Hf and elevated ~18O, so cannot be derived from the local 2020 Ma Wildman Siltstone. In contrast with younger sedimentary successions from the Pine Creek Orogen, the detrital spectra for the Cahill Formation and Nourlangie Schist contain almost no c. 1860 Ma detritus. A maximum deposition age of 1866 ± 11 Ma indicates deposition immediately prior to emplacement of the intrusive 1867-1857 Ma Nimbuwah Complex. We propose that the Cahill Formation and Nourlangie Schist were deposited at a plate margin immediately prior to convergent tectonism that resulted in their burial, deformation and amphibolite facies metamorphism during Nimbuwah Complex magmatism. These findings have implications for understanding the Paleoproterozoic evolution of the Pine Creek Orogen and the North Australian Craton as a whole.

In February-March 2004, Geoscience Australia undertook a 26 day geophysical and geological survey of the undrilled frontier depocentres of the Bremer and Denmark sub-basins. These sub-basins comprise the western part of the Bight Basin, and are located off the southern coast of Western Australia in water depths ranging from 100 to 4500 m. The survey was planned to recover rock samples and acquire high-speed seismic and swath data over the sub-basins in order to define a chronostratigraphic and depositional framework for the evolution of these depocentres. Ultimately, this information will be used to advance our understanding of the petroleum prospectivity of this frontier region.

The Early Permian to Middle Triassic Bowen and Gunnedah Basins and the Early Jurassic to Early Cretaceous Surat Basin exhibit a complex subsidence history over a period of about two hundred million years. Backstripped tectonic subsidence curves, constructed by removing the effects of processes such as sediment loading, loading due to the water column, and sediment compaction allow the subsidence histories of the basin to be examined in terms of the tectonic drivers that caused the subsidence of the basins. In the Early Permian, rapid subsidence was driven by mechanical extension, forming a series of half grabens along the western margin of the Bowen and Gunnedah Basins. Mechanical extension ceased at about 280 Ma, being replaced by a phase of passive thermal subsidence, resulting in more widespread, uniform sedimentation, with reduced tectonic subsidence rates. At the start of the Late Permian, the passive thermal subsidence phase was interrupted by the onset of lithospheric flexure during a foreland basin phase, driven by convergence and thrust loading to the east in the New England Orogen. Initially, dynamic loading, caused by viscous corner flow in the asthenospheric wedge above the west-dipping subducting plate, led to limited tectonic subsidence. Later in the Late Permian, the dynamic loading was overwhelmed by static loading, caused by the developing retroforeland thrust belt in New England, leading to very high rates of tectonic subsidence, and the development of a major retroforeland basin. Peneplanation in the Late Triassic was followed by sedimentation at the start of the Jurassic, forming the Surat Basin, where the tectonic subsidence can again be interpreted in terms of dynamically-induced platform tilting. Subduction ceased at about 95 Ma, resulting in rapid uplift, due the rebound of the lithosphere following cessation of subduction, or it stepping well to the outboard of Australia.

natural gases and 130 core samples from potential source rocks enable resolution of the generation and migration history of petroleum in the Bowen and Surat basins. Biomarker analysis confirmed a pre-Jurassic source for the petroleum.Stable carbon-isotope analysis further indicated a Permian-sourced petroleum and was able to differentiate a very minor and localised Triassic source contribution.The dominant source for the petroleum is terrestrial land plants as well as a minor marine source influence. Lower delta plain and alluvial Permian coals show thehigher liquid potential compared with upper delta plain facies. Initial liquid expulsion from the source rock occurred at vitrinite reflectance 0.65-0.7% and continued to Ro of 1.05%. This was followed by the main phase of gas generation between1.05c/o<Ro<1.4%. The gas generation enabled remobilisation of liquid petroleum for further migration. Biodegradation occurred throughout the basins' petroleummigration history, resulting in an initial regional phase of heavy palaeobiodegradation followed by a second phase of more localised and less intense in-reservoir alteration.