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  • As part of initiatives by the Australian and Queensland Governments to support energy security and mineral exploration, a deep seismic reflection and magnetotelluric survey was conducted in 2007 to establish the architecture and geodynamic framework of north Queensland. With additional support from AuScope, nearly 1400 km of seismic data were acquired along four lines, extending from near Cloncurry in the west to almost the Queensland coast.

  • As part of initiatives by the Australian and Queensland Governments to support energy security and mineral exploration, a deep seismic reflection survey was conducted in 2007 to establish the architecture and geodynamic framework of north Queensland. With additional support from AuScope, nearly 1400 km of seismic data were acquired along four lines, extending from near Cloncurry in the west to almost the Queensland coast. Important results based on the interpretation of the deep seismic data include: (1) A major, west-dipping, Paleo-proterozoic (or older) crustal boundary, which we interpret as a suture, separates relatively homogenous, thick crust of the Mt Isa Province from thinner, two layered crust to the east. This boundary is also imaged by magnetotelluric data and 3D inversion of aeromagnetic and gravity data. (2) East of the Mt Isa Province the lower crust is highly reflective and has been subdivided into three mappable seismic provinces (Numil, Abingdon and Agwamin) which are not exposed at the surface. Nd model ages from granites sampled at the surface above the western Numil and central Abingdon Seismic Provinces have very similar Nd model ages, suggesting that both provinces may have had a very similar geological history. By contrast, granites sampled above the eastern Agwamin Seismic Province have much younger Nd model ages, implying a significantly younger component in the lower crust; we consider that the Agwamin Seismic Province contains a strong Grenvillean-age component.

  • As part of initiatives by the Australian and Queensland Governments, four new seismic reflection lines and three corresponding magnetotelluric lines were acquired in 2007 over the Mt Isa, Georgetown and Charters Towers regions. These data, combined with existing multidisciplinary data, have provided new insights into the 3D architecture, geodynamics and economic potential of the North Queensland region.

  • Beginning in the Archean, the continent of Australia evolved to its present configuration through the accretion and assembly of several smaller continental blocks and terranes at its margins. Australia usually grew by convergent plate margin processes, such as arc-continent collision, continent-continent collision or through accretionary processes at subduction zones. The accretion of several island arcs to the Australian continent, through arc-continent collisions, played an important role in this process, and the geodynamic implications of some Archean and Proterozoic island arcs recognised in Australia will be discussed here.

  • Interpretation of the 2006 deep seismic reflection data across the western Lachlan Orogen of southeast Australia have provided important insights into crustal-scale fluid pathways and possible source rocks in the Victorian orogenic gold province. The seismic profiles span three of the most productive structural zones in Victoria: the Stawell, Bendigo and Melbourne zones. Variations in the age and style of gold deposits across the structural zones are reflected by changes in crustal structure and composition, as revealed by the seismic data.

  • Over the last fifteen years, Geoscience Australia, through its Onshore Energy Security Program, in conjunction with Primary Industries and Resources South Australia (PIRSA), the Geological Survey of New South Wales (Industry & Investment NSW), the Australian Geodynamics Cooperative Research Centre, and the Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC), has acquired several deep seismic reflection profiles, which, when combined, form an east-west transect about 870 km long in southeastern Australia. The seismic data vary from low-fold, dynamite-source to higher-fold, vibroseis-source data. The combined seismic profiles, from the western Eyre Peninsula to the Darling Basin, provide a near complete cross-section of the crust across the Gawler Craton, Adelaide Rift System, Curnamona Province, Koonenberry Belt and Darling Basin. The entire region is dominated by east-dipping faults, some of which originated as basin-bounding extensional faults, but most appear also to have a thrust sense of movement overprinting the extension. In the Gawler Craton, an inferred shallow, thin-skinned thrust belt occurs to the west of an inferred thick-skinned thrust belt. The boundary between the two thrust belts, the Kalinjala Mylonite Zone, was active at least during the Kimban Orogeny, with possible extensional movement at that time. The thrust movement possibly occurred during the ~1600 Ma Olarian Orogeny.

  • This report presents the results of a geodynamic synthesis of South Australia, focusing predominantly on the Archean to Mesoproterozoic of the Gawler Craton and Curnamona Province in terms of geodynamic setting, architecture, and age, using results of a geological synthesis, seismic interpretation, sequence stratigraphy, geochronology and geochemistry. This was undertaken with the dual aims: 1. To better understand the tectonic and geodynamic setting of the Gawler Craton and Curnamona Province 2. To accompany the interpretation of recently-acquired seismic reflection transects (see related product below), and to highlight new geochemical and geochronological data collected from South Australia.

  • As part of the Australian Government's Onshore Energy Security Program and the Queensland Government's Smart Mining and Smart Exploration initiatives, deep seismic reflection surveys were conducted in North Queensland to establish the architecture and geodynamic framework of this area in 2006 (Mt Isa Survey; also involving OZ Minerals and pmd*CRC) and 2007 (Cloncurry-Georgetown-Charters Towers Survey; also involving AuScope). Nearly 2300 line km of seismic data were acquired during these surveys. Geochemical, geochronological and complementary geophysical studies were undertaken in support of the seismic acquisition. Overviews of the geology of North Queensland and more detailed descriptions and the results of these surveys are presented in Hutton et al. (2009a, b), Korsch et al. (2009a), Withnall et al. (2009a, b), Henderson and Withnall (2009), and Henderson et al. (2009). The purpose here is to use the new geodynamic insights inferred from these data to provide comments on the large-scale geodynamic controls on energy and other mineral potential in North Queensland. This contribution draws on geodynamic and metallogenic overviews presented by Korsch et al. (2009b) and Huston et al. (2009)

  • Increasingly, positioning applications in hazard assessment, mining, agriculture, construction, emergency, land, utility and asset management have a demonstrated need for centimetre level or better geodetic infrastructure. However, the geodetic infrastructure in the Asia-Pacific, when compared to other geographical regions, can be generally assessed as being sparse, inhomogeneous in accuracy, infrequently realised and difficult to access. Correspondingly, it has become increasingly clear that the Asia-Pacific infrastructure is below the standard that is now available in other regions, such as Europe and the Americas, and it represents a loss in competitive advantage. The Permanent Committee for GIS Infrastructure Asia-Pacific (PCGIAP) and the International Association of Geodesy (IAG) have made some progress in developing the Asia-Pacific geodetic infrastructure; however, it can still be characterised as being a work in progress. In this presentation, we review recent efforts to improve the region's geodetic infrastructure. Specifically, we focus on crustal deformation and show results from the Asia-Pacific component of the International Association of Geodesy (IAG) working group on regional velocity fields, which includes crustal velocity estimates for over 1200 stations. This velocity field incorporates solutions derived from Continuous GPS (CGPS) data, episodic campaign based data and also velocity-only information where precise coordinates are not available. Our combination method, including our approach of incorporating velocity-only information expressed in a variety of reference frames, such as plate-fixed frames, will be overviewed. Finally, we will review the key elements of the Asia-Pacific Reference Frame (APREF) initiative, which will create and maintain a modern regional geodetic framework based on continuous GNSS data.

  • Deep seismic reflection profiles have been acquired and interpreted to better understand the crustal architecture and geodynamic evolution of Australia's geological provinces. Here, we examine some of these profiles to better understand how the Australian continent formed in the Archean and Proterozoic. The 2007 deep seismic reflection survey in North Queensland imaged a major, west-dipping, Paleoproterozoic (or older) crustal boundary, which we interpret as a suture, separating relatively nonreflective, thick crust of the Mount Isa Province in the west from thinner, two layered crust to the east. This boundary is also imaged by magnetotelluric data and 3D inversions of aeromagnetic and gravity data. Farther to the northeast, a second major boundary dips west or southwest, offsetting the Moho and extending below it. It is interpreted as a fossil subduction zone, and is overlain by supracrustal rocks of the Etheridge Province, with ages of ~1720 Ma, which is interpreted as the minimum age of the suture. Seismic profiles in southeast Australia, collected between 1996 and 2009, were combined to provide a cross section of the crust across the Archean-Mesoproterozoic Gawler Craton, Neoproterozoic-Paleozoic Adelaide Rift System, Mesoproterozoic Curnamona Province, Neoproterozoic-Paleozoic Koonenberry Belt and Silurian-Devonian Darling Basin. The transect imaged at least four discrete seismic provinces in the middle to lower crust, all bounded by east-dipping, crustal-penetrating fault zones which extend to the Moho. As the seismic provinces have not been traced to the surface, age control is poor, but they are inferred to be older that the upper crustal rocks above them, most of which are Archean to Mesoproterozoic in age.