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  • 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.

  • During 2009-10 Geoscience Australia completed a petroleum prospectivity study in the offshore northern Perth Basin, 200 km northwest of Perth. In some parts of this basin acoustic basement is deep and not resolved in the reflection seismic data. Improvements to the magnetic ship-track database and magnetic anomaly grid produced during the study allowed for assessment of depth to magnetic sources, and estimation of sediment thickness, and provided new insight into basement trends. 2.5D models along several transects, and analysis using spectral methods indicate penetration of the lower sediments by high-susceptibility bodies is necessary to approximate the observed magnetic anomaly. The reflection seismic evidence for these bodies is not obvious, though in some cases they may be associated with interpreted faults. Where the modelled bodies penetrate the sediments, they are mostly below or within the Permian section, except in the west of the study area where sediments thin over oceanic crust. On the northern-most profiles a large positive magnetic anomaly (the Batavia Ridge) is modelled by massive bodies whose tops are 5-10 km below sea floor. On these and other profiles to the south other dyke-like bodies rarely penetrate to shallower than 5 km below the sea floor.

  • This record contains the results of a geological framework study of the southern half of the Lord Howe Rise and adjacent areas, including the Tasman Basin and the New Caledonia Basin. The report particularly focuses on the geological evolution and the resource potential.

  • In mid 2011 the Australian Government announced funding of a new four year National CO2 Infrastructure Plan (NCIP) to accelerate the identification and development of sites suitable for the long term storage of CO2 in Australia that are within reasonable distances of major energy and industrial CO2 emission sources. The NCIP program promotes pre-competitive storage exploration and provides a basis for the development of transport and storage infrastructure. The Plan follows on from recommendations from the Carbon Storage Taskforce and the National CCS Council (formerly, the National Low Emissions Coal Council). It builds on the work funded under the National Low Emissions Coal Initiative and the need for adequate storage to be identified as a national priority. Geoscience Australia is providing strategic advice in delivering the plan and will lead in the acquisition of pre-competitive data. Four offshore sedimentary basins (Bonaparte, Browse, Perth and Gippsland basins) and several onshore basins have been identified for pre-competitive data acquisition and study. The offshore Petrel Sub-basin is located in Bonaparte Basin, in NW Australia, has been identified as a potential carbon storage hub for CO2 produced as a by-product from future LNG processing associated with the development of major gas accumulations on the NW Shelf. The aim of the project is to determine if the sub-basin is suitable for long-term storage, and has the potential capacity to be a major storage site. The project began in June 2011 and will be completed by July 2013. As part of the project, new 2D seismic data will be acquired in an area of poor existing seismic coverage along the boundary of the two Greenhouse Gas Assessment Areas, which were released in 2009.

  • 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.

  • The 4-10 km-thick Bangemall Supergroup, comprising the Edmund and Collier groups, was deposited between 1620 Ma and 1070 Ma in response to intracratonic extensional reactivation of the Paleoproterozoic Capricorn compressional orogen. The supergroup can be further divided into six depositional packages bounded by unconformities or major marine flooding surfaces. Samples of each of the major sandstone units within these packages have been collected for detrital zircon provenance analysis. U-Pb dating of over 1200 detrital zircon grains has failed to identify any syndepositional magmatism, but provides an extensive dataset for evaluating the provenance history of the Bangemall Supergroup and implications for the Mesoproterozoic paleogeography of the West Australian Craton. Integration of this detrital zircon data with palaeocurrent data indicates that all source areas were located within the Mesoproterozoic West Australian Craton, with the main source area for the northern Bangemall Supergroup being the Gascoyne Complex and southern Pilbara Craton. All samples have prominent age modes in the 1850-1600 Ma range, indicating significant contribution from the northern Gascoyne Complex and coeval sedimentary basins. Some samples also display prominent modes in the 2780-2450 Ma range, consistent with derivation from the Fortescue and Hamersley groups. The provenance history of the Edmund Group records unroofing of the underlying basement, from the Gascoyne Complex to the Archean granites and greenstones of the Pilbara Craton. This results in detrital age-spectra in which the dominant modes become older upwards. In contrast, the Collier Group records unroofing of the underlying Edmund Group, and is characterized by age-spectra in which the dominant modes become younger upwards. These data imply that the West Australian Craton remained intact throughout the Mesoproterozoic assembly of Rodinia, and was the only source of detritus for the Bangemall Supergroup. Keywords: Bangemall Supergroup, Edmund Group, Collier Group, paleocurrents, provenance, zircon

  • 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.