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.

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.

This report provides background information about the Ginninderra controlled release Experiment 3 including a description of the environmental and weather conditions during the experiment, the groundwater levels and a brief description of all the monitoring techniques that were trialled during the experiment. The Ginninderra controlled release facility is designed to simulate CO2 leakage through a fault, with CO2 released from a horizontal well 2 m underground. Two previous subsurface CO2 release experiments have been conducted at this facility in early and late 2012, which have helped guide and develop the techniques that have been applied herein. The aim of the third Ginninderra controlled release experiment was to further the development of detection and quantification techniques, and investigate seasonal effects on gas migration. Particular focus was given to plant health as a diagnostic detection method, via physical, biochemical and hyperspectral changes in plant biomass in response to elevated CO2 in the shallow root zone. Release of CO2 began 8 October 2013 at 4:45 PM and stopped 17 December 2013 at 5:35 PM. The CO2 release rate during Experiment 3 was 144 kg/d CO2. Several monitoring and assessment techniques were trialled for their effectiveness to quantify and qualify the CO2 that was released. The methods are described in this report and include: - soil gas - eddy covariance - mobile surveys - Line CO2 concentrations - groundwater levels and chemistry - plant biochemistry - airborne hyperspectral - soil flux - electromagnetic (EM-31 and EM-38) - meteorology This report is a reference guide to describe the Ginninderra Experiment 3 details. Only methods are described in this report, with the results of the experiment published in conference papers and journal articles.

ORIGIN AND USE OF HELIUM IN AUSTRALIAN NATURAL GASES C. Boreham1, D. Edwards1. R. Poreda2, P. Henson1. 1 Geoscience Australia, Canberra, Australia; 2 University of Rochester, NY, USA Over 800 natural gases representative of Australia's hydrocarbon-producing sedimentary basins have been analyzed for their helium (He) content and around 150 gases for their helium isotopic composition, supplemented by isotopic compositions of the higher noble gases. Australian natural gases have helium abundances to over 10%, with the highest values in the Amadeus Basin, in central Australia, while 3He/4He ratios range from around 0.01 to 4.2 Ra (Figure 1). The onshore Gunnedah Basin of southeastern Australia and the offshore Bass and onshore/offshore Otway basins in southern Australia show the highest 3He/4He ratios, indicating a significant mantle contribution. Interestingly, the offshore Gippsland Basin, adjacent to the Bass Basin, has slightly lower 3He/4He ratios. In the Gunnedah Basin, the associated CO2 has a relatively low abundance compared to extreme concentrations of CO2 in some Otway Basin wells, which are associated with recent volcanism. The onshore Bowen and Cooper basins of eastern Australia, where natural gases are predominately sourced from Permian coals, show intermediate 3He/4He ratios with the former having a higher mantle contribution. At the other end of the spectrum, low 3He/4He ratios characterize natural gases of the offshore North West Shelf (Bonaparte, Browse, Carnarvon) and onshore/offshore Perth basins in northwestern and southwestern Australia, respectively, and radiogenic helium predominates. Hence the sometimes extensive volcanic activity and igneous intrusions in these western basins is not expressed in the helium isotopes. The accompanying high CO2 contents (up to 44%) of some of these North West Shelf gases, together with the carbon isotopic composition of CO2, infer an inorganic source most likely from the thermal decomposition of carbonates. The geochemical data suggest that the origin of helium in Australian natural gas accumulations is region specific and complex with the component gases originating from multiple sources. The relative low CO2/3He ratio for many natural gases indicates a systematic loss of CO2 from most basins. The process by which CO2 has been lost from the system is most likely associated with precipitation of carbonates (Prinzhofer, 2013). The age of the source (and/or reservoir) rock has a primary control on the helium content with radiogenic 4He input increasing with residence time (Figure 1). References: Prinzhofer, A., 2013. Noble gases in oil and gas accumulations. The Noble Gases as Geochemical Tracers. Springer. 225-245.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.

The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica between 1948 – 1980s. Files include a scanned copy of the original handwritten field notebook, transcription of the notebook’s contents transcribed by volunteers and validated by an experienced geologist, and a csv file of the transcription with Text Encoding Initiative (TEI) tags. The original Antarctic field notebooks are held at the N.H. (Doc) Fisher Geoscience Library at Geoscience Australia, Canberra.