New 2D seismic data acquired in the Mentelle Basin by Geoscience Australia in 2008-09 has been used for a seismic facies study of the post-rift succession. The Mentelle Basin is a large deep to ultra deep-water, frontier basin located on Australia's southwestern margin about 200 km southwest of Perth. The study focused on the post-rift sequences deposited following the breakup between Australia and Greater India. Stratigraphic wells DSDP 258 and DSDP 264 provide age and lithological constraints on the upper portion of the post-rift succession down to mid-Albian strata. The depositional environment and lithology of the older sequences are based on analysis of the seismic facies, stratal geometries and comparisons to the age equivalent units in the south Perth Basin. Fourteen seismic facies were identified based on reflection continuity, amplitude and frequency, internal reflection configuration and external geometries. They range from high continuity, high amplitude, parallel sheet facies to low continuity, low amplitude, parallel, subparallel and chaotic sheet, wedge and basin-fill facies. Channel and channel-fill features are common in several facies as well as a mounded facies (probably contourite) and its associated ponded turbidite fill. A progradational sigmoidal to oblique wedge facies occurs at several stratigraphic levels in the section. A chaotic mound facies, probably comprising debrite deposits, has a localised distribution. Seismic facies analysis of the post-rift sequences in the Mentelle Basin has contributed to a better understanding of the depositional history and sedimentation processes in the region, as well as provided additional constraints on regional and local tectonic events.

The granite-greenstone terrains of the Eastern Goldfields Province, Yilgarn Craton, are extremely important as a major Australian gold province. The Kalgoorlie region, in particular, hosts several world class gold deposits. A grid of deep seismic reflection lines was acquired in 1999 to examine the three-dimensional geometry of the major structural features in the region within an area of the Kalgoorlie - Ora Banda region of the Eastern Goldfields Province, Yilgarn Craton. These seismic lines presented an ideal opportunity to further develop our 3D understanding of this highly mineralised granite-greenstone terrain. The seismic grid tied into the earlier 1991 regional deep seismic traverse and the more recent 1997 regional and high-resolution profiles acquired in the region. It covered and area approximately 50 km square that extended to a depth of approximately 35 km (ie the base of the crust in this area). The resulting seismic grid was well suited to the development of a three-dimensional model of the region that could be used to investigate the spatial relationships of the greenstones and the granites. The 3D geological model of this region was built using a 3D modelling software package, GOCAD(r). It was built using surface geological data and geological interpretations of the region's deep and high-resolution seismic reflection profiles. The latter seismic interpretations were constrained by gravity modelling.

No abstract available

Deep-seismic reflection data across the Archaean Eastern Goldfields Province, northeastern Yilgarn Craton, Western Australia have provided information on the crustal architecture and on several of its highly mineralised belts. The seismic reflection data contain has images of several prominent crustal scale features, including an eastward thickening of the crust, subdivision of the crust into three broad layers, the presence of a prominent east dip to the majority of the reflections and the interpretation of three east-dipping crustal-penetrating shear zones. These east-dipping shear zones are major structures that subdivide the region into four terranes. Major orogenic gold deposits in the Eastern Goldfields Province are spatially associated with these major structures. The Laverton Tectonic Zone, for example, is a highly mineralised corridor that contains several world-class gold deposits plus many smaller deposits. Other non crustal-penetrating structures within the area do not appear to be as well endowed metallogenically as the Laverton structure. The seismic reflection data have also imaged a series of low-angle shear zones within and beneath the granite-greenstone terranes. Where the low-angle shear zones intersect the major crustal-penetrating structures, a wedge shaped geometry is formed. This wedge geometry forms a suitable fluid focusing geometry where upward to sub-horizontal moving fluids are focused and then distributed into the nearby complexly deformed greenstones.

The Palaeoproterozoic to Mesoproterozoic (<1850-<1490 Ma) southern McArthur Basin, Northern Territory, Australia, contains an unmetamorphosed, relatively undeformed succession of carbonate, siliciclastic and volcanic rocks that host the McArthur River (HYC) Zn-Pb-Ag deposit. Seismic reflection data obtained across this basin have the potential to revolutionise our understanding of the crustal architecture in which this deposit formed. These data were collected in late 2002 as part of a study to examine the fundamental basin architecture of the southern McArthur Basin, particularly the Batten Fault Zone, and the nature of the underlying basement. Geoscience Australia, the Northern Territory Geological Survey and the Predictive Mineral Discovery Cooperative Research Centre combined to acquire an east-west deep seismic reflection profile (line 02GA-BT1) approximately 110 km long, commencing 15 km west of Borroloola, and extending westwards along the Borroloola-Roper Bar road to the Bauhinia Downs region (Fig. 1). A short 17 km north-south cross line (02GA-BT2) was also acquired in collaboration with AngloAmerican. The seismic data were acquired through the Australian National Seismic Imaging Resource (ANSIR).

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.

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.

Extended abstract reporting on status of geophysical work being conducted within the Remote Eastern Frontiers project.

Regional seismic reflection data in hard rock areas contains more shallow information than might first be supposed. Here I use a subset of the 2005 Tanami Seismic Survey data to show that near surface features can be defined, including paleochannels, Palaeozoic basins and structures within the Proterozoic basement. Successful imaging depends on correct determination of refraction statics, including identification of refractor branches, and use of a floating or intermediate datum during seismic reflection processing. Recognition of steep stacking velocity gradients associated with surface referenced processing aids velocity analysis and can further delineate areas of thicker regolith in palaeochannels. The first arrival refraction analysis can also be applied in more detail to estimating thickness of regolith and depth to economic basement in areas of sedimentary cover.

No abstract available