Extended abstract version of the abstract (Geocat#73747) submitted in March 2012 and accepted for an oral presentation at the symposium.

This report covers the results of a seismic reflection traverse on a portion of the Giralia anticline which has been mapped in Mesozoic and Tertiary rocks in the North-West basin. The work constitutes a part of a general programme of investigation which the Bureau of Mineral Resources, Geology and Geophysics, has been carrying out on Permit areas held by Ampol Petroleum Ltd. in this area. The seismic traverse described herein lies along the main road joining Giralia and Bullara homesteads and crosses the northern end of the Giralia structure. Tests were made with shooting in shot holes and also by air shooting. In addition, a refraction spread was shot along the axis of the anticline. This report gives an account of this investigation. Technical matters, such as interpretation technique and the symbols used in plotting results, are briefly noted. The results of the study and subsequent conclusions are discussed.

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.

The 2005 Tanami Seismic Survey was carried out from May to July for a research consortium consisting of Geoscience Australia, Geological Survey of Western Australia, Northern Territory Geological Survey, Newmont Mining and Tanami Gold. The Australian National Seismic Imaging Resource (ANSIR) was responsible for seismic data acquisition, as well as for field QC and preliminary in-field processing. The survey consisted of 720 line km along four regional deep seismic traverses, aimed at providing orthogonal three-dimensional control on the regional fault geometry. Raw data for this survey are available on request from clientservices@ga.gov.au

The Onshore Energy Security Program was funded by the Australian Government from 2006 to 2011 to reduce risk in energy exploration. The program was delivered by Geoscience Australia, in collaboration with state and territory geological surveys, the National Research Facility for Earth Sounding (ANSIR) and AuScope. During this program approximately 6,500 line kilometres of deep crustal seismic reflection data were acquired and processed. The seismic images provide an understanding of the crustal architecture of sedimentary basins and their tectonic relationship to older basement terrains. Deep crust and upper mantle structures were also imaged and the Moho boundary could often be interpreted. The 2D seismic reflection data were acquired using three vibroseis trucks, with three 12 s variable frequency sweeps at each vibration point, usually with frequencies from 6 to 96 Hz. Correlated 20 s data were recorded, imaging to approximately 60 km depth. 300 geophone groups at 40 m intervals and 80 m source intervals provided 75 fold data. Data processing included imaging shallow sedimentary basins and also complex, deep, steeply dipping crystalline rock structures with high stacking velocities and out of plane energy. The seismic data, complemented by other geophysical and geological data, helped constrain and develop geological models. These models improved the understanding of crustal architecture in known hydrocarbon and metalliferous provinces as well as in frontier geological terrains.

Terracorp under its facilities management agreement with ANSIR was contracted to conduct the 1999 Lachlan and Marsden Seismic Surveys located around West Wyalong, NSW. In total 206.47 kms of 60, 80 and 120 fold, 160 & 240 channel data was recorded between 11th September 1999 and 29th September 1999. This Eastern Lachlan Orogen project was part of the research conducted by the Australian Geodynamics Cooperative Research Centre (AGCRC), which was established under the auspices of the Commonwealth Government's Cooperative Research Centres Program in 1993. The Ordovician volcanics and associated rocks of the Eastern Lachlan Orogen are important as a significant Australian gold province. To assist mineral exploration companies in understanding the geodynamics and mineral systems of this region, the AGCRC has been collecting information that will assist in the development of geodynamic and exploration models of the region. To understand the size and architecture of the mineral system, we need to know the threedimensional geometry of the system we are dealing with. To start to address this, in 1997 the AGCRC commenced a project in the Eastern Lachlan Orogen by collecting seismic information to examine the regional scale crustal architecture as a first step towards building exploration models for the region. We continued this work in 1999 with the collection of further deep seismic reflection data along two traverses in the Forbes-West Wyalong region. The northern traverse was jointly funded by the AGCRC and the Geological Survey of New South Wales (GSNSW) as a cooperative research project. The southern traverse was funded by the AGCRC, and co-investigators in the seismic interpretation involved staff from the AGCRC at AGSO, the GSNSW, and AGSO's Gilmore Project. Raw data for this survey are available on request from clientservices@ga.gov.au

<p>Geoscience Australia conducted a deep seismic reflection test survey in the onshore portion of the Otway Basin in the southeastern part of South Australia and southwestern part of Victoria, from late October to early November 1991. The seismic test survey was undertaken to test the feasibility of recording deep seismic reflection data prior to commencing a major deep seismic reflection survey in the Otway Basin. A planned major deep seismic reflection survey by AGSO formed part of a National Geoscience Mapping Accord (NGMA) project to study the early development of the Otway Basin. The seismic reflection test survey operated for a period of three weeks, including mobilisation and demobilisation to the survey area, with five test sites occupied during the test survey. The seismic test sites were positioned to examine the feasibility of recording deep seismic reflections in areas with different outcropping rock types along the proposed main seismic lines. eMF seismic profiles were recorded along all five test lines, with uphole shoots, shot depth and charge size comparison tests performed at several of the sites. Good quality deep seismic reflection events were recorded at several of the seismic test sites. The seismic test survey was important in highlighting areas with difficult shothole drilling conditions, especially the palaeo-sand dunes along the SA-Victoria border, and the Tertiary shelly sands with shallow water table near Lake Bonney. A major seismic survey would require all shothole drilling rigs to be equipped with portable mudpits to enable shotholes to be drilled in the palaeo-sand dunes and shelly sands.<p><b>Raw data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 74948</b>

<p>Geoscience Australia conducted the Gunnedah Basin Seismic Survey during January to April 1991. The major aim of the seismic survey was to record deep seismic reflection data across the Gunnedah Basin and bounding margins. The seismic survey would also address several problems relating to the geometry of structural units and major faults. The survey recorded 253 km of eight-fold Common-Middle-Point (CMP) seismic data. The seismic data have been processed, with the data showing good seismic reflection images of the main structural features targeted in the seismic survey.<p><b>Raw data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 74952</b>

On 12th July 1960, a velocity survey of the A.A.O. Pickanjinnie No. 1 bore was made by the Bureau of Mineral Resources. The bore had been drilled to a depth of 5218 ft and was surveyed to the bottom. The average velocities for the Mesozoic rocks and the Timbury Hills Formation are similar to those measured in the Timbury Hill No. 2 bore. However, it seems impossible to correlate individual units within the Mesozoic sequence according to their velocity.

Following a month of preliminary experimental seismic work in the latter part.of 1964 the Bureau of Mineral Resources carried out a reconnaissance seismic survey of the southern part of the Georgina Basin, mainly in the Northern Territory, from April to October 1965. In most areas reflections proved very difficult to obtain. A number of different techniques were tried, including various shot andgeophone pattern arrangements, noise testing,collinear offset shooting, airshooting and multiple coverage, but no technique was found which was generally successful in providing useful reflections. The seismic results tended to confirm gravity indications that there is a shelf area between BMR 12 Bore and Tobermory and provided no indications that there are deep Palaeozoic troughs similar to the Toko -Syncline in the survey area.