From 1 - 10 / 589
  • Basin evolution of the Vlaming Sub-basin and the deep-water Mentelle Basin, both located offshore on the southwest Australian continental margin, were investigated using 2D and 3D petroleum system modelling. Compositional kinetics, determined on the main source sequences, were used to predict timing of hydrocarbon generation and migration as well as GOR evolution and phase behaviour in our 2D and 3D basin models. The main phase of petroleum generation in the Vlaming Sub-basin occurred at 150 Ma and ceased during following inversion and erosion episodes. Only areas which observed later burial have generated additional hydrocarbons during the Tertiary and up to present day. The modelling results indicate the likely generation and trapping of light oils for the Jurassic intervals for a variety of structural traps. It is these areas which are of greatest interest from an exploration point of view. The 2D numerical simulations in the Mentelle Basin indicate the presence of active hydrocarbon generating kitchen areas. Burial histories and generalized petroleum evolutionary histories are investigated.

  • The map shows the spatial distribution of short-duration rapid-onset floods and long-duration slow-rise floods. The Great Dividing Range in eastern Australia provides a natural separation of slower, wider rivers flowing west from faster, narrower coastal rivers flowing east.

  • Australian Mines and Mineral Deposit Map on gravity base, 1:5 000 000, July 2007 Version

  • Geochemical and reactive transport simulations of S.A. palaeochannel/sandstone hosted uranium systems. predictive mineral discovery CRC - PIRSA Numerical Modelling Projects Update #5

  • National Elevation Data Audit is a report outlining all elevation data available across all Australian jurisdictions which was identified by the Intergovernment Committee on Surveying and Mapping's (ICSM) Permanent Committee on Topographic Information (PCTI).

  • This paper aims to present an overview of mineral exploration highlights and hotspots in Australia for 2007. Presented at the Association of Mining and Exploration Companies National Mining Congress 7-9 June 2007, Perth Convention Centre, Western Australia.

  • Work conducted at the Bureau of Mineral Resources (now Geoscience Australia) in the early 1990s was instrumental in bringing hot rocks geothermal research and development to Australia. Following the announcement of the Australian Government's Energy Initiative in August 2006, a new geothermal project has been started at Geoscience Australia. This paper, presented at 3rd Hot Rock Energy Conference in Adelaide, August 2007, outlines the scope of the Onshore Energy Security Program and the development, implementation and progress to date of the Geothermal Energy Project.

  • During the late Neogene, the Lambert Glacier-Amery Ice Shelf drainage system flowed across Prydz Bay and showed several changes in flow pattern. In the Early Pliocene, the Lambert Glacier ice stream reached the shelf edge and built a trough mouth fan on the upper continental slope. This was associated with an increase in ice discharge from the Princess Elizabeth Land coast into Prydz Bay. The trough mouth fan consists mostly of debris flow deposits derived from the melting out of subglacial debris at the grounding line at the continental shelf edge. The composition of debris changes at around 1.1 Ma BP from material derived from erosion of the Lambert Graben and Prydz Bay Basin to mostly basement derived material. This probably results from a reduction in the depth of erosion and hence the volume of ice in the system. In the trough mouth fan, debris flow intervals are separated by thin mudstone horizons deposited when the ice had retreated from the shelf edge. Age control in an Ocean Drilling Program hole indicates that most of the trough mouth fan was deposited prior to the Brunhes Matuyama Boundary (780 ka BP). This stratigraphy indicates that extreme ice advances in Prydz Bay were rare after the mid Pleistocene, and that ice discharge from Princess Elizabeth Land became more dominant than the Lambert Glacier ice in shelf grounding episodes, since the mid Pleistocene. Mechanisms that might have produced this change are extreme inner shelf erosion and/or decreasing ice accumulation in the interior of East Antarctica. We interpret this pattern as reflecting the increasing elevation of coastal ice through time and the increasing continentality of the interior of the East Antarctic Ice Sheet. The mid Pleistocene change to 100 ka climatic and sea level cycles may also have affected the critical relationship between ice dynamics and the symmetry or asymmetry of the interglacial/glacial climate cycle duration.

  • Amplitude Versus Offset (AVO) technology has proved itself useful in petroleum exploration in various parts of the world particularly for gas exploration. To determine if modern AVO compliant processing could identify potential anomalies for exploration offshore Australia Geoscience Australia reprocessed parts of four publicly available long cable lines from two 2006 acreage release areas on the Exmouth Plateau and in the Browse Basin on the North West Shelf, and parts of two publicly available long cable lines from Geoscience Australia's Bremer Basin study on two 2005 frontier acreage release areas on the Southern Margin. The preliminary results from these three reprocessing efforts are encouraging and were made publicly available in order to assist any companies interested in the acreage. The results of the studies and associate data are available from Geoscience Australia at the cost of transfer. The AVO data over the Exmouth Plateau shows AVO anomalies including one that appears to be at the Jurassic level of the reservoir in the Jansz/Io supergiant gas field in adjacent acreage to the north. The AVO data over the Caswell Sub-basin of the Browse Basin shows an AVO anomaly at or near the stratigraphic zone of the Brecknock South 1 gas discovery to the north. The geological settings of strata possibly relating to two AVO anomalies in the undrilled Bremer Basin are in the Cretaceous in the Berriasian and in the Valanginian. The AVO anomalies from the three studies are kilometres in length along the seismic lines. These preliminary results from Geoscience Australia and other AVO work that has been carried out by industry show promise that AVO compliant processing has value particularly for gas exploration offshore Australia, and that publicly available long-cable data can be suitable for AVO analysis.

  • The mapping of seabed environments is fundamental to successful fisheries management and environmental monitoring, however, there is an emerging need to better characterise habitats based upon appropriate physical parameters. In this study, relationships between seabed geomorphology and the distribution of benthic habitats were examined using multibeam sonar, underwater video, predicted wave energy, and sediment data for Esperance Bay, part of the Recherche Archipelago. This shallow (<50 m), high energy, biogenic sediment dominated environment is located in temperate southwestern Australia. Exposure to wave energy appears to determine the distribution of unconsolidated substrate, and is the most useful regional scale predictor of rhodolith and seagrass habitats. Although they are intermittently smothered by mobile sediments, limestone reefs provide habitat for a wide range of sessile organisms, even in very high wave exposure environments. The distribution of rhodolith beds is related to poorly sorted sediments that contain high gravel, mud, and CaCO3 percentages. Our results reveal that in the Recherche Archipelago, wave abrasion coupled with localised sediment transport and accumulation play a major role in increasing the diversity of inner shelf benthic habitats. This highlights the value of assessing geomorphic processes in order to better understand the distribution and structure of benthic habitats.