Geoscience Australia carried out a marine survey on Carnarvon shelf (WA) in 2008 (SOL4769) to map seabed bathymetry and characterise benthic environments through colocated sampling of surface sediments and infauna, observation of benthic habitats using underwater towed video and stills photography, and measurement of ocean tides and wavegenerated currents. Data and samples were acquired using the Australian Institute of Marine Science (AIMS) Research Vessel Solander. Bathymetric mapping, sampling and video transects were completed in three survey areas that extended seaward from Ningaloo Reef to the shelf edge, including: Mandu Creek (80 sq km); Point Cloates (281 sq km), and; Gnaraloo (321 sq km). Additional bathymetric mapping (but no sampling or video) was completed between Mandu creek and Point Cloates, covering 277 sq km and north of Mandu Creek, covering 79 sq km. Two oceanographic moorings were deployed in the Point Cloates survey area. The survey also mapped and sampled an area to the northeast of the Muiron Islands covering 52 sq km. cloates_3m is an ArcINFO grid of Point Cloates of Carnarvon Shelf survey area produced from the processed EM3002 bathymetry data using the CARIS HIPS and SIPS software

Invited entry for reference on 'Encycolpedia of Scientific Dating Methods' about uranium-lead dating of detrital zircon.

The Canning Basin in northwestern Australia covers an area of over 506,000 sq. km, of which 430,000 sq. km are onshore. The maximum sediment thickness is over 15,000 m, concentrated in two north-west trending depocentres: the Fitzroy Trough - Gregory Sub-basin complex and the Willara Sub-basin - Kidson Sub-basin complex. Onshore sediments range in age from the Early Ordovician to Early Cretaceous while those in the offshore portion of the basin are mostly Triassic to Neogene. Though it is largely covered by onshore petroleum tenements, much of the basin is underexplored. Conventional hydrocarbons have been produced from Devonian carbonates (Blina) and Carboniferous sandstones (Boundary, Lloyd, Point Torment, Sundown, West Kora and West Terrace), with many shows in Ordovician to Permian rocks. The recent Ungani-1 well flowed oil from the Laurel Formation, while in 1967 Yulleroo-1 flowed gas from the same unit. The basin's source rocks have recently been attracting exploration attention for their unconventional hydrocarbon resources. Prospective units include the Ordovician Goldwyer and Bongabinni formations, and the Mississippian Laurel Formation. A new International Geological Timescale (Gradstein et al. 2012) has resulted in changes to the age and duration of most chronological stages. This has implications for the interpreted ages and durations of Canning Basin sedimentary units, with potential ramifications for petroleum modelling. This poster presents an updated biozonation and stratigraphy chart for the Canning Basin, reflecting the 2012 timescale. This provides a baseline for an assessment of the unconventional hydrocarbon potential of the basin, which will be conducted by Geoscience Australia.

In 2011, Geoscience Australia collected 484 km of deep-crustal (22 second) seismic reflection data. The survey (11GA-YO1) traverses the north-eastern edge of the Yilgarn Craton, the Officer Basin and the western end of the Musgrave Province. The purpose of the seismic survey was to delineate broad crustal architecture and define the Moho, with particular interest in the Yilgarn-Musgrave boundary. To compliment the seismic survey, a 3D geological model was constructed that incorporates interpretations derived from seismic, potential field, surface geology and borehole data. Forward and inverse modelling techniques were applied to the potential field data to extrapolate the seismic interpretations into 3D space. Borehole data was used to constrain the interpretation of upper crustal sequences where available. The model was later used to constrain 3D potential field inversions of the area. This poster presents a 3D geological model of the YOM region as well as the geological and geophysical constraints that were used to construct it. Some of the fundamental and technical limitations of the model are also discussed.

The shallow water equations are widely used to model flood and tsunami flows, for example to develop inundation maps for hazard and risk assessments. Finite volume numerical methods are commonly used to derive approximate solutions to these problems, because of their potential to exactly conserve mass and momentum, and correctly simulate both smoothly and rapidly varying flows. However, there remain several common scenarios which often cause numerical difficulties. The occurrence of stationary water near complex wet-dry boundaries is a standard initial condition for tsunami applications. Many numerical methods will generate spurious waves in this situation, which can propagate into the flow domain and contaminate the solution. A related situation involves the simulation of run-off caused by direct rainfall inputs, which is often desirable for flood applications as an alternative to providing discharge inputs derived from rainfall-runoff models. Conserving mass and avoiding unrealistic 'spikes' in the simulated flow velocities can be challenging, particularly when the flow depth is much shallower than the elevation range of each mesh cell, as is practically unavoidable in large scale applications. Several techniques to robustly treat these situations have been implemented in variants of the ANUGA hydrodynamic model, and the performance of these is assessed in a range of ideal and practical examples.

Due to extensive cover by Mesozoic and younger sedimentary basins and regolith, the geology of the southern Thomson Orogen is poorly understood. Small outcrops of the Thomson Orogen are exposed along the Eulo Ridge (south Qld) and in the southwest around Tibooburra (NSW). Proximal to these regions the average thickness of cover is estimated to be <200 m, which is within exploration and mining depths. The southern Thomson Orogen is true greenfields' country. Although the mineral potential of the region is largely unknown, the northeastern Thomson Orogen is well mineralised (e.g., Thalanga, Charters Towers), as is the similar-aged Lachlan Orogen to south (e.g., Cadia, Cobar, Tibooburra). In order to attract investment (exploration) into the southern Thomson Orogen, Geoscience Australia, the Geological Survey of Queensland and the Geological Survey of New South Wales have commenced a three-year collaborative project to collect new (and synthesise existing) pre-competitive data. The first year and half of the project will synthesise existing datasets across the state borders to create a revised solid geology map. This map will form the basis of a 3D model (map), which will utilise pre-existing government and industry seismic and drilling data. In support of the 3D map, several programmes of geophysical data acquisition, processing and interpretation will be undertaken. These include: airborne electromagnetic (AEM), broad-band magnetotelluric (MT) and gravity data, amongst others. In order to understand the nature of the cover rocks and their relationship to basement, a surface geochemical survey will also be completed to provide higher resolution infill of the existing National Geochemical Survey of Australia (NGSA) dataset. In addition, the potential mineral systems of the region will be assessed and a gap analysis conducted, with these results and the 3D and cover maps informing a planned drilling programme to be conducted in 2014-15. The drilling methods will be informed by the results of a similar drilling project in the Stavely Zone of western Victoria. Prior to drilling, a series of geophysical experiments will be conducted in the vicinity of the proposed holes to aid selection and improve prediction of expected cover depths. The actual drill holes will test the predictive capacity of the various pre-drilling geophysical experiments - a useful outcome in itself. The recovered core will be analysed with a range of geochemical, geochronological, geophysical and geological techniques. The combined results will be synthesised and integrated into a pre-competitive geoscience data package for exploration investment. Interim products and datasets will be released throughout the project, with the final results delivered to industry in 2016.

CONTROL ID: 1813538 TITLE: 'Big Data' can make a big difference: Applying Big Data to National Scale Change Analyses AUTHORS (FIRST NAME, LAST NAME): Norman Roland Mueller1, Steven Curnow1, Rachel Melrose1, Matthew Brian John Purss1, Adam Lewis1 INSTITUTIONS (ALL): 1. Geoscience Australia, Canberra, ACT, Australia. ABSTRACT BODY: The traditional method of change detection in remote sensing is based on acquiring a pair of images and conducting a set of analyses to determine what is different between them. The end result is a single change analysis for a single time period. While this may be repeated several times, it is generally a time consuming, often manual process providing a series of snapshots of change. As datasets become larger, and time series analyses become more sophisticated, these traditional methods of analysis are unviable. The Geoscience Australia 'Data Cube' provides a 25-year time series of all Landsat-5 and Landsat-7 data for the entire Australian continent. Each image is orthorectified to a standard set of pixel locations and is fully calibrated to a measure of surface reflectance (the 25m Australian Reflectance Grid [ARG25]). These surface reflectance measurements are directly comparable, between different scenes, and regardless of whether they are sourced from the Landsat-5 TM instrument or the Landsat-7 ETM+. The advantage of the Data Cube environment lies in the ability to apply an algorithm to every pixel across Australia (some 1013 pixels) in a consistent way, enabling change analysis for every acquired observation. This provides a framework to analyse change through time on a scene to scene basis, and across national-scale areas for the entire duration of the archive. Two examples of applications of the Data Cube are described here: surface water extent mapping across Australia; and vegetation condition mapping across the Murray-Darling Basin, Australia's largest river system.. Ongoing water mapping and vegetation condition mapping is required by the Australian government to produce information products for a range of requirements including ecological monitoring and emergency management risk planning. With a 25 year archive of Landsat-5 and Landsat-7 imagery hosted on an efficient High Performance Computing (HPC) environment, high speed analyses of long time series for water and vegetation condition are now viable. www.ga.gov.au KEYWORDS: 1906 INFORMATICS Computational models, algorithms, 1988 INFORMATICS Temporal analysis and representation, 1980 INFORMATICS Spatial analysis and representation. (No Image Selected) (No Table Selected) Additional Details Previously Presented Material: Contact Details CONTACT (NAME ONLY): Norman Mueller CONTACT (E-MAIL ONLY): norman.mueller@ga.gov.au TITLE OF TEAM:

National Geographic Information Group (NGIG) capability flyer for the upcoming Surveying & Spatial Sciences Conference 15-19 April here in Canberra.

Extended abstract version of abstract found in geocat number 74676 APPEA 2013 Extended Abstracts Volume

The subsidence histories of most, but not all, basins can be elegantly explained by extension of the lithosphere followed by thermal rethickening of the lithospheric mantle to its pre-rift thickness. Although this model underpins most basin analysis, it is unclear whether subsidence of rift basins developed over thick lithosphere follows the same trend. Here the subsidence history of the Caning rift basin of Western Australia is modelled which putatively overlies lithosphere - 180 km thick, imaged using shear wave tomography. The entire subsidence history of the, < 300 km wide and <6 km thick, western Canning Basin is adequately explained by Ordovician rifting of ~120 km thick lithosphere followed by post-rift thermal subsidence as described by the established model. In contrast, the < 150 km wide and 15 km thick Fitzroy Trough of the eastern Canning Basin, reveals an almost continuous phase of normal faulting between Ordovician and Carboniferous Periods followed by negligible post-rift thermal subsidence which cannot be accounted for by the established model. This difference in basin architecture is attributed to rifting of thick lithosphere constrained by the presence of diamond bearing lamproites intruded into the basin depocentre at ~20 Ma. In order to account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted by 50-70 kg m-3. The actual depletion of the lowermost lithospheric mantle was assessed by modelling REE concentrations of the ~20 Ma lamproites along with other ultrapotassic rocks from the Kimberley, Yilgarn and Pilbara blocks which reveal a depletion of 40-70 kg m-3. Together these results suggest that thinning of thick lithosphere to thicknesses > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal rethickening of the lithospheric mantle. The discrepancy between estimates of lithospheric thickness derived from subsidence data in the Western Canning and that derived from shear wave tomography suggests that the latter technique cannot resolve lithospheric thickness variations on < 300 km half wavelengths.