Three seismic lines (10GA-CP1, 10GA-CP2 and 10GA-CP3), which cross north to south across the Capricorn Orogen of Western Australia, have recently been collected by Geoscience Australia, ANSIR and the Geological Survey of Western Australia. The interpretation of these seismic lines is aimed at providing insight into the geologic structure of the Capricorn Orogen and to explore the relationship between the Pilbara and Yilgarn cratons. To aid in further interpretation and to add value to the seismic data an analysis of the available potential field data (gravity and magnetics) has also been undertaken. A range of geophysical data analysis techniques have been applied and include: multi-scale edge detection (worms), forward modelling and 3D inversion. By applying all three analysis techniques to the potential-field data major trends, contrasting properties and regional blocks relating to the subsurface geology have been determined, in turn, allowing for a detailed comparison with the seismic interpretation. Note that all results referred to in this abstract are preliminary and subject to change.

Predictive maps of the subsurface can be generated when geophysical datasets are modelled in 2D and 3D using available geological knowledge. Inversion is a process that identifies candidate models which explain an observed dataset. Gravity, magnetic, and electromagnetic datasets can now be inverted routinely to derive plausible density, magnetic susceptibility, or conductivity models of the subsurface. The biggest challenge for such modelling is that any geophysical dataset may result from an infinite number of mathematically-plausible models, however, only a very small number of those models are also geologically plausible. It is critical to include all available geological knowledge in the inversion process to ensure only geologically plausible physical property models are recovered. Once a set of reasonable physical property models are obtained, knowledge of the physical properties of the expected rocks and minerals can be used to classify the recovered physical models into predictive lithological and mineralogical models. These predicted 2D and 3D maps can be generated at any scale, for Government-funded precompetitive mapping or drilling targets delineation for explorers.

The first RSTT model for Australia has been developed based on the Australian Seismological Reference Model (AuSREM) that was released in late 2012. The densely-gridded P and S wave distributions of the crust and upper mantle of AuSREM have been simplified and translated into the 7 layer crustal and upper mantle RSTT model. Travel times computed with this RSTT model are evaluated against travel times computed in full 3D through the AuSREM model to assess the impact of the approximations used by RSTT. Location estimates of 5 ground truth earthquakes (GT1, GT2 and GT5) using the global ak135 reference model, the RSTT model and the full 3D travel times are compared. It is found that the RSTT model can reproduce the 3D travel times fairly accurately within its distance of applicability, thereby improving location estimates compared to using a global travel time model like ak135. However the benefit of using RSTT for locating Australian earthquakes is far less than using full 3D travel times, mainly because most stations tend to be further away from the source than the distance of RSTT applicability.

Preliminary compilation of data in the onshore Carptentaria Basin, Northern Territory. This basin, previously named the Dunmarra Basin, is poorly understood. This Record details the compilation of data in 3D for the basin. Data included are surface geological mapping, drillholes, gravity, magnetic, radiometric, visible LANDSAT, seismic reflection and digital elevation data.

Predictive 3D geological models of the subsurface can be developed using a range of available tools. Each tool is suited to slightly different problems and datasets. The method described here, using the UBC-GIF inversions algorithms, allows rapid development of models using an objective, automated procedure. It has flexibility to include as little or as much geological information as is available, making it ideal for greenfields exploration or mapping programs. The steps involved are: 1) develop a solid understanding of the expected physical properties; 2) convert geological observations into physical property constraints; 3) perform geologically-constrained inversions; 4) apply geological classifier to recovered 3D physical property models. The procedure is demonstrated for the southern Agnew-Wiluna greenstone belt in WA, a highly mineralised region with a high proportion of surface cover. The predictive 3D lithology models developed for the area are particular effective at mapping the extent of dense mafic and magnetic ultramafic rocks, and provide new insights about their distribution at depth.

The GA Animator Software is a tool used to create high quality fly-through animations of geoscience data for internal and external stakeholders. It is build using the NASA World Wind Java SDK, as a companion tool to the publicly available 3D Data Viewer.

Seismic activity in the region around Australia results in a significant tsunami hazard to the coastal areas of Australia. Hence seismicity is monitored in real time by Geoscience Australia (GA), which uses a network of permanent broadband seismometers. Although seismic moment tensor (MT) solutions are routinely determined using 1-D structural models of Earth, we have recently demonstrated that a 3-D model of the Australian continent developed using full waveform tomography significantly improves the determination of MT solutions of earthquakes from tectonically active regions. A complete-waveform, time-domain MT inversion method has been developed using a point-source approximation. We present a suite of synthetic tests using first a 1-D and then a 3-D structural model. We study the feasibility of deploying 3-D versus 1-D Earth structure for the inversion of seismic data and we argue for the advantages of using the 3-D structural model. The 3-D model is superior to the 1-D model, as a number of sensitivity tests show. Current work is focused on a real time automated MT inversion system in Australia relying on Australian and other international stations.

A movie flythrough displaying various geological and geophysical data used for petroleum prospectivity assessment of the offshore northern Perth Basin

Extended abstract describing metallogenic significance of georgina-Arunta seismic line. The abstract discusses mainly the Neoproterozoic and Phanerozoic mineral potential, including implications to U, Cu-Co, Au, Cu-U and energy.

This is a 3 minute movie (with production music), to be played in the background during the October 28th 2010 Geoscience Australia Parlimentary Breakfast. The video shows a wide range of the types of activities that GA is involved in. These images include GA people doing GA activities as well as some of the results of offshore surveys; continental mapping; eath monitoring etc. The movie will be played as a background before and after GA's CEO (Chris Pigram) presentation.