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  • This study demonstrates that seabed topography and geodiversity play key roles in controlling the spatial dynamics of large fish predators over macro-ecological scales. We compiled ten years of commercial fishing records from the Sea Around Us Project and developed continental-scale catch models for an assemblage of large open-water fish (e.g. tuna, marlins, mackerels) for Western Australia. We standardised catch rates to account for the confounding effects of year, gear type and species body mass using generalised linear models, from which relative indices of abundance were extracted. We combined these with an extensive array of geophysical, oceanographic, biological, and anthropogenic data to (1) map the location of pelagic hotspots and (2) determine their most likely mechanistic drivers. We tested whether submarine canyons promote the aggregation of pelagic fish, and whether geomorphometrics (measures of seafloor complexity) represent useful surrogate indicators of their numbers. We also compared predicted fish distributions with the Australian network of Commonwealth Marine Reserves to assess its potential to provide conservation benefits for highly mobile predators. Both static and dynamic habitat features explained the observed patterns in relative abundance of pelagic fish. Geomorphometrics alone captured more than 50% of the variance, and submarine canyon presence ranked as the most influential variable in the North bioregion. Seafloor rugosity and fractal dimension, salinity, ocean energy, current strength, and human use were also identified as important predictors. The spatial overlap between fish hotspots and marine reserves was very limited in most parts of the EEZ, with high-abundance areas being primarily found in multiple use zones where human activities are subject to few restrictions.

  • Version 1 of the Water Theme of the Land Cover of Australia (Water25) is an ISO 19144-2 classification of the percentage of successful observations from Landsat 5 TM and Landsat 7 ETM+ sensors in which water was detected. Each satellite image pixel is an observation; Successful observations are those in which the land surface is clearly seen (unobscured by clouds for example) and quality checks are passed. Classes: - Perennial (water observed more than 75% of the time) - Non-perennial 60%-75% (water observed from 60 to 75% of the time) - Non perennial 30%-60% (water observed from 30 to 60% of the time) - Non perennial 8%-30% (water observed from 8% to 30% of the time) - Land subject to infrequent inundation 1%+ (water observed from 1% to 8% of the time) - No water observed Water25 can be used to map and characterise inland water bodies and provides information about the observed extent of inundation for waterways and floodplains. It is a resource for both users and providers of information about surface water permanence and the extent and frequency of inundation. Potential users include government agencies, research institutions, the general public and academia.

  • Oil and gas discoveries in Australia's offshore basins are concentrated on the North West Shelf (Northern Carnarvon, Browse and Bonaparte basins) and Bass Strait (Gippsland, Otway and Bass basins). While discoveries have been made in a few regions outside these areas (e.g. Perth Basin), a large proportion of Australia's offshore basins remain exploration frontiers. However, the decline in oil production from the North West Shelf and Bass Strait basins since 2000 has led to an increasing exploration interest in the frontier basins. There are 35 offshore frontier basins, sub-basins and provinces located on Australia's northern, northwestern, southwestern, southern, southeastern and remote eastern continental margins, where no hydrocarbons have been discovered, but where the presence of hydrocarbon accumulations is considered possible (Figure 1). These basins are diverse in terms of geology, prospectivity and accessibility, ranging from old (e.g. Proterozoic-Paleozoic Arafura Basin) to young (e.g. Mesozoic-Cenozoic Barcoo Sub-basin), from areas widely acknowledged to be highly prospective (e.g. Ceduna Sub-basin) to those where the prospectivity is more difficult to assess (e.g. Sorell Basin), and from the nearshore (e.g. offshore Sydney Basin) to the remote (e.g. New Caledonia Basin). Geoscience Australia recently completed a report on the geology and prospectivity of frontier basins in the Australian Maritime Jurisdiction, titled 'Petroleum Geology Inventory of Australia's Offshore Frontier Basins'. This study provides a comprehensive overview of the geology, petroleum systems, exploration status and data coverage for all offshore frontier basins, sub-basins and provinces, along with an assessment of the critical science questions and exploration uncertainties for each area. This work draws on the results of Geoscience Australia's pre-competitive data programs conducted from 2003 to 2011, as well as exploration results and the geoscience literature. The study assigns a petroleum prospectivity ranking to each basin, based on the presence or absence of evidence for the existence of active petroleum systems (Table 1). The availability of data and level of knowledge in each area is reflected in a confidence rating for that ranking (Table 2). While the prospectivity of some areas is widely acknowledged to be high (e.g. Ceduna Sub-basin), the perception of prospectivity in many basins is negatively affected by the amount or quality of data available. In these basins, the acquisition of new data or targeted research could make a significant difference to the understanding of petroleum potential and likelihood of exploration success.

  • Mafic and ultramafic rocks hosted by metamorphosed deep marine sediments in the Glenelg River Complex of SE Australia comprise variably tectonised fragments of a late Neoproterozoic-earliest Cambrian hyper-extended continental margin that was dismembered and thrust westward over the adjacent continental margin during the Cambro-Ordovician Delamerian-Ross Orogeny. Ultramafic rocks include serpentinised harzburgite of inferred subcontinental lithospheric origin that had already been exhumed at the seafloor before sedimentation commenced whereas mafic rocks exhibit mainly E- and N-MORB basaltic compositions consistent with emplacement into a deep marine environment floored by little if any continental crust. Contrary to previous suggestions, these rocks and their metasedimentary host rocks are not a more distal correlative of the Cambrian Kanmantoo Group. The latter is host to basaltic rocks with higher degrees of crustal contamination and a detrital zircon population with a prominent peak at 500-600 Ma. Except for quartz greywacke in the uppermost part of the sequence, the Glenelg River Complex is devoid of detrital zircon, pointing to deep marine sedimentation far removed from any continental margin. Deep seismic reflection data support the idea that the Glenelg River Complex is underlain by a substrate of mafic and ultramafic rocks and preclude earlier interpretations based on aeromagnetic data that the continental margin hosts a thick pile of seaward-dipping basaltic flows analogous to those developed along volcanic margins in the North Atlantic.

  • The Early Cretaceous South Perth Shale has been previously identified as the regional seal in the offshore Vlaming Sub-basin. The South Perth Shale is a deltaic succession, which unfilled a large palaeotopographic low in the Early Cretaceous through a series of transgressive and regressive events. The new study undertaken at Geoscience Australia has shown that the seal quality varies greatly throughout the basin and at places has very poor sealing properties. A re-evaluation of the regional seal based on seismic mapping determined the extent of the pro-delta shale facies within the South Perth Shale succession, which are shown to provide effective sealing capacity. New sequence stratigraphic interpretation, seismic facies mapping, new and revised biostratigraphic data and well log analysis were used to produce palaeogeographic reconstructions which document the distribution of depositional facies within the South Perth Shale Formation and reveal evolution of the Early Cretaceous deltas. Our study documents spatial variations in the seal quality and re-defines the extent and thickness of the regional seal in the central Vlaming Sub-basin. It provides an explanation for the lack of exploration success at some structural closures and constraints for possible location of the valid plays.

  • Four posters describing work being undertaken in Antarctica: VULNERABLE MARINE ECOSYSTEMS IN ANTARCTICA SEABED MAPPING IN ANTARCTICA DEFINING ABSOLUTE GRAVITY AN ANTARCTIC GEODESY

  • Powerpoint presentation for "Advanced Topics in Carbon Capture and Storage" 7-10 April, Porto Alegre, Brazil

  • The Eucla-Gawler deep seismic reflection line (13GA-EG1), which was completed in February 2014, forms the 'missing piece' in a now complete east-west transect of the continent. The new line joins the previously acquired Albany-Fraser Orogen line (12GA-AF3) at Haig (WA), extending the seismic coverage for a further 834 km eastwards to Tarcoola (SA). The data were acquired by Geoscience Australia, the Geological Survey of Western Australia, and the Geological Survey of South Australia as part these institutions' pre-competitive data acquisition programmes, with data-infrastructure investment from AuScope to complete the line. The investment provides new, fundamental data in a hitherto little-known region of Australia with the aim of encouraging exploration investment and ultimately new mineral resource discovery, as well as improving knowledge of the structure and evolution of the continent. The Eucla-Gawler region (Nullarbor Plain) is a major geological frontier, with very little information available on the subsurface geology and its context. The region lies between two of the most prospective geological regions in the world, with the Yilgarn Craton to the west and the Gawler Craton to the east, however, the extensive sedimentary cover associated with the Eucla Basin has led to the bedrock underlying this region being very poorly represented and understood. Some of the geological unknowns in this region include the: - deep crustal structure of the sub-Eucla Basin basement geology as a whole and the likely geological processes that drove Mesoproterozoic tectonic assembly between the West Australian Craton and the South Australian Craton; - deep crustal structure of the eastern margin of the Albany-Fraser Orogen and western margin of the Gawler Craton; - nature of the Mundrabilla Shear Zone as a crustal-scale fault structure; - nature and character of the Moho; - margins of the Coompana magnetic feature and associated magnetic lineaments; - structural relationships between tectonic units mapped at the surface (such as neotectonic features); and, - structural elements of the Eucla Basin and underlying basins, which may host hydrocarbons. A wide range of interpreted geological settings in this region have the potential to be highly prospective for regional, greenfields mineral exploration. This includes the: - cratonic margins, such as the western margin of the Gawler Craton, which are settings that typically host conduits for deeply sourced mineralising fluids and depositional sites; - Coompana magnetic feature and its margins in the southwest of South Australia. Previous interpretations suggest parallels with geological systems hosting Cu-Ni sulphides elsewhere, such as in Western Australia (e.g., the Nova deposit immediately to the west); - highly prospective (e.g., Ni-Cu) mafic rift sequence in the western Gawler Craton associated with the Fowler Domain; and, - provenance and transport pathways for heavy mineral sands (HMS) that have accumulated in Eucla Basin sediments and are presently mined at Jacinth-Ambrosia. The data are of excellent quality, despite limestone and karst conditions in the Eucla Basin. This talk will present the un-migrated field stacks of the full crustal sections (20 second two-way-time); answering some of the geological unknowns.

  • Abstract for the 2014 Australian Population Association Conference, 3-5 December, Hobart

  • Map showing Australia's Maritime Jurisdiction in the Timor Sea. Updated in June 2014 from "Australia's Maritime Jurisdiction in the Timor Sea" (GeoCat 68796) to conform with "Australian Maritime Boundaries 2014" data by Geoscience Australia. One of the 27 constituent maps of the "Australia's Maritime Jurisdiction Map Series" (GeoCat 71789). Depicting Australia's continental shelf as proclaimed in the "Seas and Submerged Lands (Limits of Continental Shelf) Proclamation 2012" established under the "Seas and Submerged Lands Act 1973". Background bathymetric image is derived from a combination of the 2009 9 arc second bathymetric and topographic grid by GA and a grid by Smith and Sandwell, 1997. Background land imagery derived from Blue Marble, NASA's Earth Observatory. A0 sized .pdf downloadable from the web.