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  • A general lack of exploration success in the offshore northern Perth Basin sheared margin has lead to a perception that the primary source rock onshore (Triassic Kockatea Shale Hovea Member) is absent or has limited generative potential. However, recent offshore well studies show the unit is present and oil prone. Multiple palaeo-oil columns were identified within Permian reservoirs below the Kockatea Shale seal. This prompted a trap integrity study into fault reactivation as a critical risk for hydrocarbon preservation. Breach of accumulations could be attributed to JurassicEarly Cretaceous extension, Valanginian breakup, margin tilt or localised Miocene inversion. This study focused on four prospects, covered by 3D seismic data, containing breached and preserved oil columns. 3D geomechanical modelling simulated the response of trap-bounding faults and fluid flow to Jurassic-Early Cretaceous NW-SE extension. Calibration of modelling results against fluid inclusion data, as well as current and palaeo-oil columns, demonstrates that along-fault fluid flow correlates with areas of high shear and volumetric strains. Localisation of deformation leads to both an increase in structural permeability promoting fluid flow, and the development of hard-linkages between reactivated Permian reservoir faults and Jurassic faults producing top seal bypass. The main structural factors controlling the distribution of permeable fault segments are: (i) failure of faults striking 350??110?N; (ii) fault plane intersections generating high shear deformation and dilation; and (iii) preferential reactivation of larger faults shielding neighbouring structures. These results point to a regional predictive approach for assessing trap integrity in the offshore northern Perth Basin. While this approach will help explorers reduce risk the study highlights the need to identify other play types that avoid fault seal breach. An as yet untested potential basin floor fan stratigraphic play in the Abrolhos Sub-basin and analogues to the successful Cretaceous stratigraphic traps along the West African sheared margin in the Zeewyck Sub-basin may satisfy these criteria.

  • Geoscience Australia (GA) has been developing the National Exposure Information System (NEXIS), a national database of exposure information to identify elements in both the built environment and community that are at risk from natural disasters. A key component of NEXIS is the description of each building including footprint area and height; these geometric characteristics can be derived from LiDAR. This investigation is an assessment of the current abilities of GA and industry partners to provide this data. GA holds LiDAR data representing 70% of the places Australians live, however most of these dataset have not been processed to identify buildings. Five software methods and five industry partners were assessed for their ability to do two main tasks: identify or classify buildings in the LiDAR point clouds, and extract geometric characteristics of buildings. The extracted features were assessed using an urban LiDAR point cloud that has good accuracy and a high data density. Feature-based and area-based assessment methods were developed to assess the output of software packages against a reference building dataset provided by the Launceston Council. The various methods achieved a producer's accuracy between 80% and 90%, user's accuracy between 70% and 90%, and overall accuracy between 90% and 95%.

  • Presentation to "Advanced Topics in Carbon Capture and Storage" on overview of CCS in Australia

  • This USB has been produced for promotional puposes and will be handed out (free) at domestic and international conferences. The USB contains a selection of reports, flyers, maps and data. Products are grouped into 4 categories: Records and Brochures, Mineral Deposits, Geophysical Data and Surface Geology.

  • Geochemical surveys collect sediment or rock samples, measure the concentration of chemical elements and report these typically either in weight percent or in parts per million. There are usually a large number of elements measured and the distributions are often skewed, containing many potential outliers. We present a new robust principal component analysis (PCA) method for geochemical survey data, which involves first transforming the compositional data onto various different manifolds using power transformations. A flexible set of moment assumptions are made which take the special geometry of each manifold into account. The Kent distribution moment structure arises as a special case when the chosen manifold is the hypersphere. We derive simple moment and robust estimators of the parameters which are also applicable in high dimensional settings. The resulting PCA based on these estimators is effectively done in the tangent space and is closely related to the power transformation method used in correspondence analysis. To illustrate, we analyse major oxide data from the National Geochemical Survey of Australia. When compared with the traditional approach in the literature based on the centred logratio transformation, the new PCA method is shown to be more successful at dimension reduction and gives more interpretable results.

  • Knowledge of the nature of buildings within business areas is fundamental to a broad range of decision making processes, including planning, emergency management and mitigating the impact of natural disasters. To support these activities, Geoscience Australia has developed a building information system called the National Exposure Information System (NEXIS) which provides information on buildings across Australia. Most of the building information in NEXIS is statistically derived, but efforts are being made to include more detailed information on the nature of individual buildings, particularly in flood prone areas. This is being achieved in Bundaberg through field survey work.

  • Survey of businesses following the 2013 floods in Bundaberg

  • 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.

  • The Neoproterozoic to Palaeozoic Thomson Orogen occupies a large portion of eastern Australia but is poorly known due to extensive cover. Currently, models for the tectonic evolution of the Thomson Orogen and its relationship to surrounding elements largely focus on the exposed areas. The long and complex structural and thermal history interpreted from these outcropping rocks raises many questions as to the age and origin of rocks in the vast undercover portion of the Thomson Orogen. Glimpses of the undercover Thomson Orogen are revealed in basement intersections of petroleum drill cores throughout central and south-western Queensland. These are dominated by low grade metasedimentary rocks (dominantly turbidites) with minor volcanic rocks and granites. New in-situ zircon analysis for U-Pb (SHRIMP) and Lu-Hf (Laser ablation multi-collector ICP-MS) isotopes are presented here and provide new temporal and provenance information for the rocks occurring beneath cover. Two distinct detrital zircon signatures are identified. A 'Pre-Gondwana' signature is identified in two drill holes on the north-western margin of the Thomson Orogen, adjacent to the North Australian Craton (GSQ Machattie 1, HPP Goleburra 1). These samples both have near-unimodal zircon age peaks at ~1180 Ma. -Hf (900-1300Ma) values from HPP Goleburra 1 display a range of -Hf(t) between 0 and 9 representing a moderately juvenile source. These sediments were possibly derived from the Musgrave Province in central Australia during the Cambrian Petermann Orogeny. Comparable detrital zircon age spectra from the Amadeus and Officer Basins suggests that the Thomson Orogen was connected and formed part of the greater Centralian Superbasin during this period. The second detrital zircon signature is identified extensively throughout the Thomson Orogen in basement drill cores (GSQ Eromanga 1, AAO Beryl 1, GSQ Maneroo 1, DIO Naryilco 1, DIO Betoota 1) and the outcropping Puddler Creek Formation and Les Jumelles Beds. This signature is remarkably consistent and characterised by a dominant age peak at ~570 Ma, a lesser population between ~1300-900 Ma and maximum depositional ages of ~495 Ma. This pattern is termed the 'Pacific Gondwana' detrital zircon signature and is widely recognised in eastern and central Australia and Antarctica. -Hf(500-700) data for Thomson Orogen rocks with this signature is highly variable with -Hf(t) values between -20 and 8 suggesting input from multiple source regions. Our isotopic work suggests connectivity between the Centralian Superbasin and the Thomson Orogen during and after the ~570-530 Ma, Petermann Orogeny. Parts of the uplifted Musgrave Province remained the dominant source of sediments until at least the late Cambrian when the Pacific Gondwana signature became dominant in the Thomson Orogen and central Australian basins.