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  • This is a compilation of all the processed multibeam bathymetric data that Geoscience Australia holds in its database for the Bremer Sub-Basin. The location of the sub-basin lies in deep water off the southwest margin of WA between Albany and Esperance at the western end of the Great Australian Bight.

  • Measurements of water turbidity, currents, seafloor sediment samples and geophysical data document the sedimentary processes and the Late Quaternary sedimentary history of a continental shelf valley system on the East Antarctic continental margin.

  • 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.

  • This record summarises the physical environments of the seabed for the Ceduna and Eyre Sub-basins.

  • This report contains the preliminary results of Geoscience Australia survey 266 to central Torres Strait. The survey was undertaken to investigate the seabed geomorphology and sedimentary processes in the vicinity of Turnagain Island and to infer the possible effects (if any) on the distribution, abundance and survival of seagrasses. The Turnagain Island region was chosen because it is a known site of recent widespread seagrass dieback. The present survey is the first of two by Geoscience Australia to be carried out in 2004 and is part of a larger field-based program managed by the Reef CRC aimed at identifying and quantifying the principal physical and biological processes operating in Torres Strait. The impetus for the program is the threat of widespread seagrass dieback and its effects on local dugong and turtle populations and the implications for indigenous islander communities.

  • A quantitative synthesis of the sedimentology and geomorphology of the South West Planning Region of Australia. Sediment data used was sourced from previous and new quantitative carbonate and grainsize data generated from surficial seabed sediment samples. All sample information and assays are available in the MARS database. The report and new assays were generated as part of an MOU with the Department of Environment and Heritage (National Oceans Office) and the results are reported in a format appropriate for use in regional marine planning.

  • This report is one of a series of environmental summaries of frontier basins, which are scheduled for acreage release during the timeframe of the 'Energy Security Initiative' (2007-2011). The aim of these reports is to synthesise the available environmental information to adequately equip the exploration industry to anticipate as many as possible of the environment-related issues that may impact on exploration and potential future production activities. The environmental information for the Vlaming Sub-basin and Mentelle Basin has been compiled and presented in a manner consistent with the Geographic Information System (GIS) provided with this report. The GIS includes the results of an analysis to obtain representative seascapes. Seascapes are the principal environmental output and in recent years assisted Department of Environment, Water, Heritage and the Arts with the design and implementation of a National Representative System of Marine Protected Areas for Australia (Section 1.1). The following section summarises the geological history of the Vlaming Sub-basin and Mentelle Basin and provides a tectonic and depositional context for the geophysical data and geomorphology of the sub-basin, which are discussed in Sections 3 and 4, respectively. The surface sediment properties are described in Section 5. These sections provide all of the information necessary to characterise benthic habitats. Section 6 discusses the oceanographic processes operating in the sub-basin, which influence both the benthic and pelagic ecology described in Section 7. Section 8 synthesises the information contained in the first seven sections into a seascape map of the Vlaming Sub-basin and Mentelle Basin.

  • A geological reconnaissance was made of an area of approximately 27,000 square miles lying north and west of Katherine in the Northern Territory. The report is compiled in two parts. The first concerns general geology and includes accounts of the nomenclature, stratigraphy, structural geology, geological history, and geomorphology of the area. The second part comprises a summary of the economic geology. The mining industry, petroleum prospects, underground water, and recommendations are discussed. A table showing the mineral production figures for the Northern Territory, northern district, is appended.

  • Abstract: The Collaborative East Antarctic Marine Census (CEAMARC) surveys to the Terre Adélie and George V shelf and margin highlight the requirement for a revised high resolution depth model that can be used as a spatial tool for improving physical models of the region. We have combined available shiptrack and multibeam bathymetry, coastline and land topographic data to develop a new high-resolution depth model, called GVdem. GVdem spans an area 138°E to 148°E longitude and 63°S to 69°S latitude, with a choice of three ESRI grids with cell pixel sizes: 15 arcsec, 9 arcsec and 3.6 arcsec. The revised depth model is an improvement over previously available regional-scale grids, and highlights seabed physiographic detail not previously observed for this part of East Antarctica. In particular, the extent and complexity of the inner-shelf depressions are revealed and their relationship with large shelf basins and adjacent flat-topped banks.

  • This record is a review and synthesis of geological research undertaken along the northern margin of Australia. The record has been written in support of regional marine planning and provides fundamental baseline scientific information for the Northern Planning Area.