The Onshore Energy Security Program, funded by the Australian Government and conducted by Geoscience Australia, has acquired deep seismic reflection data, in conjunction with State and Territory geological surveys, across several frontier sedimentary basins to stimulate petroleum exploration in onshore Australia. Here, we present data from two seismic lines collected in South Australia and the Northern Territory. Seismic line 08GA-OM1 crossed the Carboniferous to Permian Arckaringa Basin is imaged as a series of depocentres forming the Phillipson and Penrhyn Troughs, with a much thinner succession connecting the depocentres, and extending well to the north. Seismic line 08GA-OM1 also crosses the Neoproterozoic to Devonian eastern Officer Basin. The basin is structurally complex in this area, being dominated by south-directed thrust faults and fault-related folds, providing potential for underthrust petroleum plays. Seismic line 08GA-OM1 also images the southern margin of the Amadeus Basin Seismic line 09GA-GA1 crossed the northeastern part of the Amadeus Basin and the complete width of the southern Georgina Basin in the Northern Territory. Structural and sequence stratigraphic interpretations of the seismic lines will be presented here, to be followed by an assessment of the petroleum potential of the basins. In the northeast, seismic line 09GA-GA1 crosses two parts of the basin separated by the Paleoproteroozic to Mesoproterozoic Casey Inlier. Seismic line 09GA-GA1 was positioned to cross that part of the southern Georgina Basin where the basin has a complex southern margin, with Neoproterozoic stratigraphy being thrust interleaved with basement rocks of the Arunta Region.

Abstract: The Tasman Frontier region is a vast submerged continental fragment of over 3,000,000 sq km between Australia, New Zealand and New Caledonia. It hosts a number of unexplored sedimentary basins, some of which may share a common geological origin with the Taranaki and Gippsland basins, where petroleum production is established. The Tasman Frontier database is a compilation of all digital seismic reflection data that can be made publicly available. The database contains c. 100,000 km of seismic lines that have been modified to common segy format with uniform header information so that they can be easily loaded into a computer workstation. The project is a collaborative initiative between GNS Science, Geoscience Australia and Service Géologique de Nouvelle-Calédonie. GNS Science Report 2012/01, which contains the database as a supplement, can be obtained from GNS Science (gns.cri.nz). The report outlines the exploration history and geological setting of the region, gives a technical description of the database, and specifies licence terms and registration instructions for users.

The Onshore Energy Security Program was funded by the Australian Government for five years (2006-2011) to provide geological information on some of the frontier onshore sedimentary basins in Australia, many of which are underexplored with respect to hydrocarbons. As part of the Onshore Energy Security Program, deep seismic reflection data have been acquired across several frontier sedimentary basins to stimulate petroleum exploration in onshore Australia. In 2009, Geoscience Australia, in conjunction with the Northern Territory Geological Survey, acquired a deep seismic transect 373 km long across (Figure 1) the Georgina Basin and northeast margin of the Amadeus Basin of the Northern Territory.

Many of the onshore sedimentary basins in Australia are underexplored with respect to hydrocarbons. The Onshore Energy Security Program was funded by the Australian Government over five years (2006-2011) for Geoscience Australia to provide precompetitive geoscience data and assessments of the potential of some frontier onshore sedimentary basins for energy resources, including hydrocarbons, uranium, thorium and geothermal energy. The basins studied in this project include the Burke River Structural Zone of the Georgina Basin (northwest Queensland), the Yathong Trough in the eastern Darling Basin (western New South Wales), and the Arrowie Basin (South Australia). The interpretation of deep seismic reflection profiles and petroleum systems maturation modelling was undertaken in these basins to increase the understanding of their petroleum potential. The Arrowie Basin seismic data shows an asymmetrical basin architecture, with the basin fill being ~3800 m at its thickest. Several sequence boundaries are mapped in this seismic section, and are correlated with the sequence boundaries between the major Neoproterozoic stratigraphic groups in the Adelaide Rift System. In the easternmost part of the seismic section, a series of east-dipping thrust faults disrupt the stratigraphic section. The petroleum systems maturation modelling shows that potential Cambrian source rocks are likely immature to mature for oil generation. In contrast, potential Neoproterozoic source rocks are likely to be mature to overmature for oil generation, and immature to mature for gas generation. With hydrocarbon systems clearly present in the Arrowie Basin as shown by bitumen in shallow exploration wells drilled in the 1950's, future work, possibly with a focus on unconventional hydrocarbons, would be warranted. The Burke River Structural Zone of the Georgina Basin seismic data shows the basin is ~65 km wide, with a half-graben geometry, being bounded in the west by a rift border fault. The succession in the basin has a maximum thickness of ~2800 m, with the stratigraphy being relatively flat lying, and thickening towards the west. The petroleum systems maturation modelling shows potential Cambrian source rocks are likely to be oil mature. Significant generation and expulsion probably occurred early in the burial history, in response to Cambrian-Ordovician loading. Expulsion occurred after trap formation in the Neoproterozoic-Cambrian, but before later trap formation in the Devonian. The required long preservation time and unroofing are the major risk factors within the basin. The Yathong Trough of the Darling Basin seismic data interpretation shows that the basin fill consists of a thick succession characterised by alternating high and low amplitude seismic reflections, interpreted to represent the expected Devonian succession mudstones and sandstones. The basement units below the Yathong Trough are interpreted to be Ordovician turbidites and Ordovician-Silurian granites, considered to be part of the Lachlan Orogen. The petroleum systems maturation modelling shows that potential Lower and Middle Devonian source rocks are likely to be overmature for oil generation and mature for gas generation. Generation and expulsion from Lower and Middle Devonian potential marine source rocks occurred early during their burial history, prior to Carboniferous uplift and erosion, and thus, major trap formation. Later burial during the Permian and/or Cretaceous may have resulted in minor gas generation and expulsion from a Middle Devonian potential source rock.

A reflection traverse was shot across the centre part of the Giralia Anticline in the Carnarvon Basin of Western Australia, in an attempt to verify the unconformity between Mesozoic and Palaeozoic sediments shown by a previous traverse across the northern part of the anticline. Shallow seismic events recorded were of good quality and correlated very well with surface geology. They also indicated two faults in places where steep dips in surface beds might, by analogy with the northern end, be expected. Deep events were in general of poor quality and inconsistent. However, over approximately a mile of the traverse, they were of good quality and indicated nonconformity with the shallow events.

A seismic reflection survey was carried out in the Parish of Darriman, Victoria. The survey was planned to investigate a gravity anomaly, which may be an indication of a structure within the sedimentary section favourable to the accumulation of oil or natural gas. For the most part reflections were exceptionally good, and it was possible to trace one reflecting layer over most of the area. Contouring showed the presence of an anticlinal structure, plunging to the east, but rising and broadening to the west. On the flat crest of the structure, there is probable closure in two places. The thickness of the Tertiary sediments may be a maximum of 6,000 feet, but may be only 3,000 feet on the crest of the structure and 4,000 feet on the flanks.

In 2009, as part of its Onshore Energy Security Program, Geoscience Australia, in conjunction with the Northern Territory Geological Survey, acquired 373 km of vibroseis-source, deep seismic reflection, magnetotelluric and gravity data along a single north-south traverse from the Todd River in the south to nearly 30 km north of the Sandover Highway in the north. This traverse, 09GA-GA1, is referred to as the Georgina-Arunta seismic line, extends from the northeastern Amadeus Basin, across the Casey Inlier, Irindina and Aileron provinces of the Arunta Region and Georgina Basin to the southernmost Davenport Province. Here, we report the results of an initial geological interpretation of the seismic and magnetotelluric data, and discuss some preliminary geodynamic implications.

Initial 2D seismic survey using mini-vibroseis with high frequency band 10 - 150Hz. This seismic survey is part of the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) projects.

Geoscience Australia conducted the Albany Fraser Orogen 2D Seismic Survey in 2012. The survey involves the acquisition of seismic reflection and gravity Data over the Yilgarn Craton margin and the Albany Fraser Orogen of Western Australia. The survey consisted of four lines, totalling 677kms. The project is a collaborative project between Geoscience Australia and the Geological Survey of Western Australia and is part of the ongoing cooperation under the National Geoscience Agreement (NGA). Funding of this project is through the Western Australian Government's Royalties for Regions Exploration Incentive Scheme. The primary objective of the project is to Image the crustal architecture of the Yilgarn Craton margin and its relationship to the Albany-Fraser Orogen and establish the subsurface extent of the Yilgarn Craton beneath the Albany-Fraser Orogen, and look for mantle-tapping structures that may have provided fluid pathways for mineralization. The seismic lines are designed to cross several major faults, such as the Cundeelee Fault, the Fraser Fault, the Newman Shear Zone, and the Red Island Shear Zone. A 70km long deep crustal seismic line was also acquired near the Tropicana Gold mine with the assistance of AuScope Earth Imaging, Anglo Gold Ashanti and the Independence Group. The purpose of this line was to image the crustal architecture as well as to understand the structural geometry around the Tropicana gold deposit and help define prospective areas elsewhere along the belt. Raw data for this survey are available on request from clientservices@ga.gov.au

<p>Geoscience Australia conducted a seismic survey in the central Eromanga Basin in Queensland from July to Late November 1982. This survey was a continuation of the work undertaken in 1980 and 1981 to investigate the structure, stratigraphy, geological and tectonic evolution, and petroleum potential of the area. The survey obtained 485 km of six-fold Common-Depth-Point reflection data, in the Adavale Basin, Cooladdi Trough and Pleasant Creek Arch areas.<p><b>Raw data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 74970</b>