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  • Annular to crescent-shaped low back scatter SAR slicks over carbonate reefs and shoals in the Timor Sea with slick `feathering', and within the coral spawning period for the region, are interpreted to be caused by a coral spawn event. In contrast, ocean current data and detailed swath bathymetry of the sea floor to the southeast of the coral spawn slicks suggest that elongate repeating slicks in this area are related to current flow over submarine channels. Assessment of these slicks in association with ancillary data, such as bathymetry, current velocities, weather and timing of scene capture allow a more robust interpretation of their origins. Through differentiating coral spawn and bathymetric slicks from oil and other biological slicks in shallow carbonate systems, such as the Timor Sea, petroleum and environmental assessments for these areas can be improved.

  • Map Index indicating the availability of the Department of Defence produced 50K topographic mapping. Folded copies only which are available free of charge. Product Specifications Coverage: Australia Currency: 2004 (PDF); 2004 (data) Coordinates: Geographical Datum: GDA94 Format: ArcInfo Export, ArcView Shapefile and MapInfo mid/mif; PDF (maps only); Paper Map (maps only) Medium: GIS Data Free online, free folded map or CD-ROM (fee applies) Forward Program: Updated annually

  • Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The Early Mesoproterozoic (1600 Ma - 1570 Ma) was a period of widespread compressional tectonism and high geothermal gradient metamorphism in the Australian Proterozoic. In the eastern half of the North Australian Craton, the bulk of Palaeoproterozoic terrains underwent high-temperature tectonism between 1600 Ma to 1550 Ma. In central Australia, the Chewings Orogeny (1600 Ma - 1570 Ma) was associated with approximately north-south shortening coeval with regional low-pressure high-temperature metamorphism up to granulite grade. In northeastern Australia, the Early Isan (1600 Ma - 1580 Ma), and Ewamin-Janan Orogenies (1585 Ma - 1555 Ma) in the Mt Isa and Georgetown and Yambo Inliers, respectively, were also associated with approximately north-south shortening and high geothermal gradient metamorphism. In the southern Australian Proterozoic, the Olarian Orogeny (1610 Ma - 1585 Ma) in the Curnamona Province was also characterised by high geothermal gradient metamorphism. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

  • Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The 2005 Tanami Seismic Collaborative Research Project was developed to provide a better understanding of the crustal architecture and mineral systems of the Tanami region within Western Australia and the Northern Territory. This was achieved through the acquisition of four regional scale deep crustal seismic reflection profiles. The Tanami Seismic Collaborative Research Project involved Geoscience Australia, the Northern Territory Geological Survey, the Geological Survey Western Australia, Newmont Exploration Pty Ltd and Tanami Gold NL. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

  • Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The King Leopold and Halls Creek Orogens in the Kimberley region of northern Australia are divided into three distinct terranes, each representing a different tectonic setting, that may be part of a larger, diverse collisional orogen on a scale similar to the present Alpine-Himalayan Orogen. Collision with the Kimberley Craton drove intracratonic deformation in the adjacent Tanami and Arunta regions of the North Australian Craton. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

  • Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The North Australia Project of Geoscience Australia had, as its starting point, the review of event chronology in the Arunta Region compiled by Collins and Shaw (1995) and only sparse dating coverage in the Tanami and Tennant regions. The knowledge-base was still dominated by younger systems, which overprinted the Palaeoproterozoic rocks. Early attempts to unravel the pre-1700 Ma evolution with SHRIMP U-Pb dating had not yet identified all of the major event systems and their scope. In the absence of detailed timing constraints, regional correlations were conjectural or based on perceived litholigical links. The prevailing model was that the earliest evolution across the Proterozoic inliers of northern Australia comprised two major basin phases separated by a single correlated orogenic episode, the 'Barramundi Orogeny', which created and defined the North Australian Craton as a tectonic domain (Etheridge et al., 1987, Meyers et al., 1996). Detailed regional re-mapping, combined with a program of imaging-assisted SHRIMP U-Pb dating studies, has led to a new understanding. Several distinct events are now recognised and there are many basin phases separated by a variety of stratigraphic and/or tectonic surfaces. Although major issues are yet to be resolved, there is greater confidence in reconstructing the evolution and metallogeny of individual regions. Some key inter-region correlations can now be demonstrated at the scale of individual formations, unconformities or events. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

  • Initial 2D seismic survey using mini-vibroseis with high frequency band 10 - 150Hz. This seismic survey is part of the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) projects.

  • Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The Tanami Region (TANAMI and THE GRANITES 1:250 000 map sheet areas) is centrally located within the North Australian Craton and contains a gold-mineralised Palaeoproterozoic orogenic sequence. Page et al (1995) postulated Neo-Archaean granitic gneiss as basement to the Tanami Group, although no lower sedimentary contact has been observed. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>

  • Noble gas and halogen constraints on mineralizing fluids of metamorphic versus surficial origin: Mt Isa, Australia

  • Presented at the Evolution and metallogenesis of the North Australian Craton Conference, 20-22 June 2006, Alice Springs. The Pine Creek Orogen (PCO) is part of the North Australian Craton and is correlated with other Palaeoproterozoic domains of northern Australia. Archaean (>2.5 Ga - 2.7 Ga) granite and metamorphics are overlain by Palaeoproterozoic strata comprising sandstone, mudstone, and minor carbonates and volcanics. Its age is constrained between 2.5 Ga and 1.86 Ga, and the succession is divided into two supergroups. The older Woodcutters Supergroup comprises <2.5 Ga to 2.02 Ga arenites, stromatolitic dolostone, and pyritic carbonaceous shale. The younger Cosmo Supergroup comprises BIF, mudstone, and tuff, succeeded by a monotonous flysch sequence. Zircons from the tuff beds provided an age of 1863 Ma, confirming a major depositional break of about 150 million years. <p>Related product:<a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=64764">Evolution and metallogenesis of the North Australian Craton Conference Abstracts</p>