This service represents a combination of two data products, the DEM_SRTM_1Second dataset and the Australian_Bathymetry_Topography dataset. This service was created to support the CO2SAP (Co2 Storage application) Project to create a transect elevation graph within the application. This data is not available as a dataset for download as a Geoscience Australia product. The DEM_SRTM_1Second service represents the National Digital Elevation Model (DEM) 1 Second product derived from the National DEM SRTM 1 Second. The DEM represents ground surface topography, with vegetation features removed using an automatic process supported by several vegetation maps. eCat record 72759. The Australian_Bathymetry_Topography service describes the bathymetry dataset of the Australian Exclusive Economic Zone and beyond. Bathymetry data was compiled by Geoscience Australia from multibeam and single beam data (derived from multiple sources), Australian Hydrographic Service (AHS) Laser Airborne Depth Sounding (LADS) data, Royal Australian Navy (RAN) fairsheets, the General Bathymetric Chart of the Oceans (GEBCO) bathymetric model, the 2 arc minute ETOPO (Smith and Sandwell, 1997) and 1 arc minute ETOPO satellite derived bathymetry (Amante and Eakins, 2008). Topographic data (onshore data) is based on the revised Australian 0.0025dd topography grid (Geoscience Australia, 2008), the 0.0025dd New Zealand topography grid (Geographx, 2008) and the 90m SRTM DEM (Jarvis et al, 2008). eCat record 67703. IMPORTANT INFORMATION For data within this service that lays out of the Australian boundary the following needs to be considered. This grid is not suitable for use as an aid to navigation, or to replace any products produced by the Australian Hydrographic Service. Geoscience Australia produces the 0.0025dd bathymetric grid of Australia specifically to provide regional and local broad scale context for scientific and industry projects, and public education. The 0.0025dd grid size is, in many regions of this grid, far in excess of the optimal grid size for some of the input data used. On parts of the continental shelf it may be possible to produce grids at higher resolution, especially where LADS or multibeam surveys exist. However these surveys typically only cover small areas and hence do not warrant the production of a regional scale grid at less than 0.0025dd. There are a number of bathymetric datasets that have not been included in this grid for various reasons.

Magnetotelluric (MT) measures the natural variations of the Earth's magnetic and electrical (telluric) fields. The Audio-Magnetotelluric method (AMT) samples signals in the frequency range of 10k Hz down to ~1Hz and provides information to the upper few kilometres of the crust. AMT data were collected at ten sites in the southern Thomson Orogen using Phoenix Geophysics equipment (MTU-5A, MTC-150L and PE5 electrodes). Instrument deployment periods were 7/Oct -29/Oct 2015 and 03/Aug-10/Aug 2016. Time series data were processed into frequency domain using remote reference and Robust Processing scheme. After quality assurance, processed data were exported to industry-standard EDI files. Time series data are available on request.

Seismic data, calibration and State of Health files. 2005-2007

The product consists of 8,800 line kilometres of time‐domain airborne electromagnetic (AEM) geophysical data acquired over the far north part of South Australia known as the Musgrave Province. This product release includes: a) the measured AEM point located data, b) electrical conductivity depth images derived from the dataset, and c) the acquisition and processing report. The data were acquired using the airborne SkyTEM312 Dual Moment 275Hz/25Hz electromagnetic and magnetic system, which covered a survey area of ~14,000 km2, which includes the standard 1:250 000 map sheets of SG52-12 (Woodroffe), SG52-16 (Lindsay), SG53-09 (Alberga) and SG53-13 (Everard). The survey lines where oriented N-S and flown at 2km, 500m and 250m line spacing. A locality diagram for the survey is shown in Figure 1. This survey was funded by the Government of South Australia, as part of the Plan for Accelerating Exploration (PACE) Copper Initiative, through the Department of the Premier and Cabinet, (DPC) and the Goyder Institute of Water Research. Geoscience Australia managed the survey as part of a National Collaborative Framework project agreement with SA. The principal objective of this project was to capture a baseline geoscientific dataset to provide further information on the geological context and setting of the area for mineral systems as well as potential for groundwater resources, of the central part of the South Australian Musgrave Province. Geoscience Australia contracted SkyTEM (Australia) Pty. Ltd. to acquire SkyTEM312 electromagnetic data, between September and October 2016. The data were processed and inverted by SkyTEM using the AarhusInv inversion program (Auken et al., 2015) and the Aarhus Workbench Laterally Constrained Inversion (LCI) algorithm (Auken et al. 2005; Auken et al. 2002). The LCI code was run in multi-layer, smooth-model mode. In this mode the layer thicknesses are kept fixed and the data are inverted only for the resistivity of each layer. For this survey a 30 layer model was used. The thickness of the topmost layer was set to 2 m and the depth to the top of the bottommost (half-space) layer was set to 600 m. The layer thicknesses increase logarithmically with depth. The thicknesses and depths to the top of each layer are given in Table 1. The regional AEM survey data can be used to inform the distribution of cover sequences, and at a reconnaissance scale, trends in regolith thickness and variability, variations in bedrock conductivity, and conductivity values of key bedrock (lithology related) conductive units under cover. The data will also assist in assessing groundwater resource potential and the extent of palaeovalley systems known to exist in the Musgrave Province. A considerable area of the survey data has a small amplitude response due to resistive ground. It very soon becomes evident that lack of signal translates to erratic non-monotonic decays, quite opposite to the smooth transitional exponential decays that occur in conductive ground. Some sections of the data have been flown over what appears to be chargeable ground, hence contain what potentially can be identified as an Induced Polarization effect (airborne IP—AIP). For decades these decay sign changes, which characterize AIP, have not been accounted for in conventional AEM data processing and modelling (Viezzoli et al., 2017). Instead they have mostly been regarded as noise, calibration or levelling issues and are dealt with by smoothing, culling or applying DC shifts to the data. Not accounting for these effects is notable on the contractor’s conductivity-depth sections, where data can’t be modelled to fit the data hence large areas of blank-space have been used to substitute the conductivity structure. The selection of the survey area was undertaken through a consultative process involving the CSIRO, GOYDER Institute, Geological Survey of South Australia and the exploration companies currently active in the region (including industry survey partner PepinNini Minerals Ltd). The data will be available from Geoscience Australia’s web site free of charge. It will also be available through the South Australian Government’s SARIG website at https://map.sarig.sa.gov.au. The data will feed into the precompetitive exploration workflow developed and executed by the Geological Survey of South Australia (GSSA) and inform a new suite of value-added products directed at the exploration community.

To purchase this product, contact the Geoscience Australia Sales Centre via: email:clientservices@ga.gov.au; fax: +61 2 6249 9960; or phone: 1800 800 173 (within Australia); +61 2 6249 9966 (outside Australia). The map covers an area of 0.850 degrees longitude by 0.883 degrees latitude or about 76 kilometres from east to west and about 96 kilometres from north to south. At this scale 1cm on the map represents 1km on the ground. This map contains natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 20m), localities and administrative boundaries, such as national parks, and nature reserves. The reverse side of the map depicts the same area using an orthophoto mosaic.

The Australian Geoscience Data Cube has won the 2016 Content Platform of the Year category at the Geospatial World Leadership Awards. The awards recognise significant contributions made by champions of change within the global geospatial industry and were presented during the 2017 Geospatial World Forum held in Hyderabad, India. The Data Cube was developed by Geoscience Australia in partnership with the CSIRO and the National Computational Infrastructure at the Australian National University, and is a world-leading data analysis system for satellite and other Earth observation data. Visit www.datacube.org.au to find out more including the technical specifications, and learn how you can develop your own Data Cube and become part of the collective.

Interpretation of newly acquired seismic data in the northern Houtman Sub-basin (Perth Basin) suggests the region contains potential source rocks similar to those in the producing Abrolhos Sub-basin. The regionally extensive late Permian–Early Triassic Kockatea Shale has the potential to contain the oil-prone Hovea Member source interval. Large Permian syn-rift half-graben, up to 10 km thick, are likely to contain a range of gas prone source rocks. Further potential source rocks may be found in the Jurassic-Early Cretaceous succession, including the Cattamarra Coal Measures, Cadda shales and mixed sources within the Yarragadee Formation. This study investigates the possible maturity and charge history of these different source rocks. A regional pseudo-3D petroleum systems model is constructed using new seismic interpretations. Heat flow is modelled using crustal structure and possible basement composition determined from potential field modelling, and subsidence analysis is used to investigate lithospheric extension through time. The model is calibrated using temperature and maturity data from 9 wells in the Houtman and Abrolhos sub-basins. Source rock properties are assigned based on an extensive review of TOC, Rock Eval and kinetic data for the offshore northern Perth Basin. Petroleum systems analysis results show that Permian, Triassic and Early Jurassic source rocks may have generated large cumulative volumes of hydrocarbons across the northern Houtman Sub-basin, whilst Middle Jurassic‒Cretaceous sources remain largely immature. However the timing of hydrocarbon generation and expulsion with respect to trap formation and structural reactivation is critical for the successful development and preservation of hydrocarbon accumulations.

From the beginning of petroleum exploration in the Perth Basin, the importance of the Early Triassic marine Kockatea Shale was recognised as the principal source for liquid petroleum in the onshore northern Perth Basin (Powell and McKirdy, 1976). Thomas and Barber (2004) constrained the effective source rock to a Early Triassic, middle Sapropelic Interval in the Hovea Member of the lower Kockatea Shale. In addition, Jurassic and Permian sourced-oils (Summons et al., 1995) demonstrate local effective non-Kockatea source rocks. However, evidence for multiple effective gas source rocks is limited. This study utilizes the molecular composition and carbon and hydrogen isotopic compositions of 34 natural gases from the Perth Basin, extending the previous study (Boreham et al., 2001) to the offshore and includes hydrogen isotopes and gases. It shows the existence of Jurassic to Permain gas systems in the Perth Basin.

The Browse Basin is located offshore on Australia's North West Shelf and is a proven hydrocarbon province hosting gas with associated condensate; however, oil reserves are small. The assessment of a basin's oil potential traditionally focusses on either the presence or absence of oil-prone source rocks. However, light oil can be found in basins where the primary hydrocarbon type is gas-condensate and oil rims form whenever these fluids migrate into reservoirs at pressures below their dew point (or saturation pressure). The relationship between dew point pressure and condensate-gas ratio (CGR) depends on the liquid composition and is therefore a petroleum system characteristic (Fig. 1). By combining geochemical studies of source rocks and fluids with petroleum systems analysis, the four Mesozoic petroleum systems identified by their geochemical fingerprints (Rollet et al., 2016) can be correlated with several gas-prone (dew point) petroleum systems: 1. Gas-condensates generated and reservoired within the Lower-Middle Jurassic Plover Formation are derived from terrestrial organic matter in fluvio-deltaic to pro-deltaic environments. Such gas is dominated by methane (gas dryness* = 91%), with ideal gas condensate ratios (CGRs) ranging between 7 and 35 bbl/MMscf. Liquids recovered from wells tested along the Scott Reef Trend (e.g. Calliance, Brecknock and Torosa) comprise pale yellow condensates (49-53° API gravity), as do those from the deepest (Plover) reservoirs within the Ichthys gas accumulation (e.g. Gorgonichthys). These liquids plot on Figure 1 as dew point fluids. The molecular and carbon isotopic signatures of these condensates are similar, classifiying them into a single family (W1_1BRO) in Figure 2. The biomarkers providing the strongest discrimination are the high relative abundances of C29 sterane and C19 tricyclic triterpane, coupled with an enrichment in delta13C of their saturated and aromatic hydrocarbon fractions testifies to their terrestrial organic origin. 2. Fluids with similar bulk properties (gas dryness = 91%; ideal CGRs 27-52 bbl/MMscf) to those of the aformentioned Plover-sourced fluids are found in the greater Crux accumulation in the Heywood Graben. The pale yellow condensates (47°API gravity) also exhibit similar biomarker assemblages as the W1_1BRO family. However, due to their greater enrichment in delta13C, the condensates plot as a separate family (W1_2BRO) in Figure 2. A difference in thermal maturity is also noted, with the Crux accumulation having lower maturity (calculated vitrinite reflectance# [Rc] = 0.77%) relative to the condensates on the Scott Reef Trend (av Rc = 1.18%). The most likely source rocks for the Crux fluids are the terrestrially-dominated Plover Formation coals and shales, but shaly coals also occur within the thick Upper Jurassic section in the northern part of the basin. These fluids are categorised as a separate dew point system within the Heywood Graben (Fig. 1). 3. Gas-condensates reservoired within the Brewster Member of the upper Vulcan Formation in the Ichthys/Prelude and Burnside accumulations have a greater liquid content than the aformentioned gases, with ideal CGRs of 22-151 bbl/MMscf at Titanichthys 1 and a gas dryness of 84%. The pale yellow condensates have API gravities of 55° and are potentially a separate intraformational dew point petroleum system within the central Caswell Sub-basin. Their biomarker and isotopic signatures indicate derivation from mixed marine and land-plant organic matter and plot as another family (W2W3_1BRO; Fig. 2). The source of these fluids is probably the organic-rich shales of the Upper Jurassic-Lower Cretaceous Vulcan Formation that encase the Brewster Member sandstone reservoir. PVT data for Brewster-reservoired fluids is affected by synthetic mud contamination, which has an impact on the measured dew point pressures. In the absence of measured values, a similar phase behaviour to North Sea (UK) gas-condensates (England, 2002) is assumed. 4. The Cretaceous reservoir in Caswell contains an unbiodegraded brown 'light oil' (47°API gravity) but PVT data are not available. Biomarker and isotope signatures show that the liquids were generated from source rocks containing both marine and terrigenous organic matter lying within the early oil window (Rc# = 0.75%). They correlate with the Yampi Shelf biodegraded oils (W3_1BRO, Fig. 2), gas at Adele, and with extracts of the Lower Cretaceous Echuca Shoals Formation (Boreham et al., 1997). However, these marine shales have low hydrogen indices (~200 mg hydrocarbons/gTOC) and hence may only be able to expel sufficient hydrocarbons to sustain migration over short distances. Since biodegraded solution gases in the Yampi Shelf accumulations contain neo-pentane - a highly resistant compound - with isotopic affinity to Plover Formation generated fluids, it is possible that Cretaceous-sourced liquids were mobilised and carried to the shelf edge by co-migrating Plover-derived gas.

This poster shows earthquakes occurring in Australia in 2016 with a background of earthquake activity in Australia over the past 10 years. Also included are images produced as part of the analysis of the Petermann Ranges Earthquakes -, the offshore Bowen Earthquakes -, and the Norsemann Earthquakes Sequences. A yearly summary of earthquake occurrences in Australia as well as the top 10 Australian earthquakes in 2016 are presented.