Deep seismic reflection profiles in mineral provinces in Australia are used to identify the main crustal-scale architecture which is the key to determining regional scale controls on mineralisation and possible fluid migration pathways. The results constrain the crustal architectures during the building of 3D geological maps of the regions, and are challenging our current understanding of the geology, ore deposit models and prospectivity of Australia.

The new acquisition of multibeam bathymetry data along with potential field, seismic data and sediment and rock samples has provided a large quantity of new data in the Northern Lord Howe Rise. A detailed study of the relationships between the surface and sub-surface features over the Capel and Faust basins suggests that seafloor deformation is linked to the underlying basement architecture. Numerous seafloor and sub-surface geological features have been identified and mapped over the study area. Their nature, distribution and relationships have been analysed to propose their formative mechanisms. Most of these features are related to buried igneous intrusions and fluid flow either located within depocentre megasequences or along basement bounding faults. The co-genetic geological features indicate that fluid flow is mainly driven by igneous activity. The ongoing fluid flows, after each magmatic pulse has re-utilised pre-existing fluid conduits. Major depocentres have been identified over the study area and could be prospective for petroleum exploration. Potential source, reservoir and seal rocks are likely to be present in the capel and Faust basins. Volcanic activity has driven the geology and fluid flow over the study area since at least the Upper Cretaceous and has to be considered when assessing the petroleum prospectivity of the Capel and Faust basins and also elsewhere in the Lord Howe Rise.

The ~400 km long Central Victorian deep crustal reflection seismic survey was carried out in 2006 as a collaborative project between the pmd*CRC, Geoscience Australia, the Victorian Government, Ballarat Goldfields NL, Gold Fields Australasia Pty Ltd and Perseverance Corporation Limited using the facilities of ANSIR. The aim was to cross several basement zones and provide information on the crustal architecture, particularly across the highly prospective Palaeozoic rocks occurring along strike to the north of the major Victorian goldfields. The Moyston Fault, which forms the boundary between the Delamerian Orogen to the west and the Stawell Zone to the east, is an east-dipping planar fault that cuts through the entire crust to the Moho. The boundary between the Stawell Zone and the Bendigo Zone farther to the east is the Avoca Fault, which appears to be a west-dipping listric fault that links to the Moyston Fault at a depth of about 22 km, forming a Y-shaped geometry. Faults that are internal to the Stawell and Bendigo zones are almost entirely west-dipping listric faults, that cutp the highly reflective lower crust of these zones. The boundary between the Bendigo and Melbourne zones, the Heathcote Fault Zone, forms a zone of strong west-dipping reflections several kilometres wide to a depth of at least 20 km, and possibly to the Moho. The Governor Fault, separating the Melbourne Zone from the Tabberabbera Zone, is a very low-angle north-dipping fault. The seismic character of the lower crust below the Melbourne Zone (the "Selwyn Block")is significantly different to that observed below the Bendigo and Stawell zones, and consists of a series of very strong subhorizontal reflections about 5-6 km thick starting at about 18 km depth, with a less reflective zone below it.

The 2008 Rankins Springs Seismic Survey was a joint initiative by Geoscience Australia and NSW Department of Primary Industries under the Onshore Energy Security Program (OESP) in the under-explored southeastern Darling Basin. Regional acquisition parameters of 300 channels, 40 m group interval and 80 m vibration point interval nevertheless allowed detailed imaging of a 3 second (TWT) thick sedimentary sequence in the Yathong Trough. Use of three 12 second vari-sweeps from truck mounted Hemi 50 (50,000 lb) vibrators provided sufficient energy to image from immediately below regolith to the Moho. The sweep frequency ranges 6 - 64, 10 - 96 and 8 - 80 Hz were chosen both for deep penetration and high resolution in the sedimentary section. In-field processing produced a high quality preliminary section on a daily basis using an iterative process of automatic residual statics calculation on a deep gate and interactive stacking velocity analysis. Both automatic statics and stacking velocity were essential for successful imaging, but velocity was more important, as initial estimates based on first arrival velocities produced a degraded section. The field seismic section clearly shows a fault bounded trough, with evidence of compressional structures in the upper part and hints of underlying older sedimentary basins. The in-field stacking velocity analysis also provided immediate evaluation of the maximum depth of the trough, namely 6 km, deeper than expected. Efficient in-field processing allows early notification to project partners of a successful survey, facilitating future planning, and provides a sound basis for streamlined subsequent processing.

The Capel and Faust basins are located in a remote part of deepwater offshore eastern Australia. They are largely Cretaceous rifts formed within a 1600 km long ribbon of continental crust (the Lord Howe Rise) that became detached from Australia during the fragmentation of the eastern Gondwana plate margin and the opening of the Tasman Basin. As part of Geoscience Australia (GA)'s ongoing work to identify and evaluate the resource potential of Australia's offshore frontier basins, approximately 6 000 km of industry-standard, 106-fold 2D seismic data was acquired over the Capel and Faust basins during late 2006 and early 2007. These data supplemented earlier, sparse regional seismic data and were complemented by the acquisition of approximately 24 000 km2 of multibeam bathymetry and 11 000 line kilometres of shipboard gravity and magnetic data by GA in late 2007. This record details the interpretation of the seismic data and is intended to complement the release of a digital version of the interpretations in workstation formats (GeoFrame, Kingdom). Scientific conclusions drawn from the seismic interpretations and, very importantly, from an integration of the seismic, potential field and other data sets are beyond the scope of this record and are published in other GA Records, scientific papers and conference proceedings volumes.

Legacy product - no abstract available

Seismic reflection, seismic refraction and portable broadband data collected within Western Australia's Yilgarn Craton, in particular the Eastern Goldfields Province, are providing detailed images of several of its highly mineralized terranes as well as new insights into the crustal architecture of the region. When the results from these seismic techniques are integrated, the results are providing a better understanding of the structure of the crust and lithosphere beneath the Yilgarn Carton, from the surface to depths in excess of 300 km.

Legacy product - no abstract available

This record contains interpreted seismic profiles (scale 1:200K) and background text for nine of the areas that were included in the Australian submission for an extended Continental Shelf. These areas include: Argo; Australian Antarctic Territory; Great Australian Bight; Kerguelen Plateau; Lord Howe Rise; Naturaliste Plateau; South Tasman Rise; Three Kings Ridge; and the Wallaby-Exmouth Plateaus.

The Stuart Shelf overlies the eastern portion of the Gawler Craton. This part of the Gawler Craton is South Australia's major mineral province and contains the world-class Olympic Dam Cu-U-Au deposit and the recent Cu and Au discovery at Prominent Hill. The Stuart Shelf is several kilometres thick in places. As such, little is known of the crustal structure of the basement, its crustal evolution or its tectono-stratigraphic relationship to adjacent areas, for example the Curnamona Province in the east. There has been much effort applied to advancing our understanding of basement, mainly through the use of potential field data and deep drilling programmes; though drilling has proved very costly and very hit and miss. The Stuart Shelf area needs new data and methods to bring our knowledge of it to the next level of understanding. At a Gawler Craton seismic planning workshop held in July 2001, stakeholders from industry, government, and university stakeholders identified several criteria fundamental to undertaking any seismic survey within the Gawler Craton. These were - Location of seismic traverse across a known mineral system in order to improve understanding and enhance knowledge of the region's mineral systems. Access to surface and/or drill hole geological knowledge to link geology data with the seismic interpretation. Good coverage of potential field data, and Potential for the seismic data to stimulate area selection and exploration in the survey region.