From 1 - 10 / 285
  • Overview of the Deep Crustal Seismic surveys conducted by Geoscience Australia and funded through the Onshore Energy Security Program since it's commencement in 2006 to September 2009.

  • Geoscience Australia has been acquiring deep crustal reflection seismic transects throughout Australia since the 1960s. The results of these surveys have motivated major interpretations of important geological regions, contributed to the development of continental-scale geodynamic models, and improved understanding about large-scale controls on mineral systems. Over the past five years, Geoscience Australia has acquired over 6000 km of deep crustal seismic reflection data under the auspices of the Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC), Onshore Energy Security Program (OESP), AuScope Earth Imaging (part of the National Collaborative Research Infrastructure Strategy), and all mainland State and Territory governments. These seismic datasets continue to underpin fundamental research into the geodynamics of the Australian continent and provide the third dimension for pre-competitive geoscience information related to mineral and energy resources in selected provinces and basins. Regional seismic reflection surveys currently utilise three Hemi 50 or 60 vibrators at 80 m VP with 40 m group interval, resulting in 75 fold data to 20 s TWT. In-house processing is aimed at providing a whole of crust image, without sacrificing shallow detail. Gravity readings are also collected along the lines at 400 m intervals to assist integrated regional interpretations based on the seismic traverses. Magnetotelluric (MT) soundings, including both broad-band and long period, have been acquired along most traverses. MT provides an image of the conductivity of the crust which is complementary to the structural information obtained from reflection seismic. Geoscience Australia is currently developing an in-house MT processing and modelling capability.

  • 3D visualisation of the Mount Isa Crustal Seismic Survey

  • Case Study: GeoFrame software helps Geoscience Australia provide quick access to 2D and 3D seismic survey data within newly released license/permit in support of successful Australian Acreage Release bidding rounds

  • 3D visualisation of the Mount Isa Crustal Seismic Survey

  • The Bureau of Mineral Resources, Geology and Geophysics (BMR) did a reconnaissance seismic survey in the central portion of the Bowen Basin in November, 1960. The objectives of the survey were to determine the structure of the Basin and the thickness of sediments by traversing from the western margin of the Basin near Anakie to the eastern margin east of Duaringa. Two other seismic surveys conducted in this Bowen Basin are Cooroorah Anticline seismic survey in 1959 (survey L037) and 254km seismic survey near the towns of Duaringa and Blackwater (survey L129).

  • Processed Stacked and Migrated SEG-Y seismic data and section images for the Youanmi Deep Crustal Seismic Survey. This survey was conducted under a National Geoscience Agreement with the Western Australia Geological Survey. Funding was through the Onshore Energy Security Program and Western Australia's Exploration Incentive Scheme. The objective of the survey was to image the northwest Yilgarn Craton to the Ida Fault crossing the Meekatharra structural zone, a focus of gold mineralization. Data are supplied as SEG-Y files, TIFF and PDF images. Raw data for this survey are available on request from clientservices@ga.gov.au

  • AGSO's northwest Australian margin project (NWAM) aims to provide a high level understanding of the geological framework of the entire northwest margin of the continent, with particular emphasis on the crustal and basin architecture. The following studies are currently addressing these objectives: 1) ArcView GIS, 2) Potential field and bathymetric grids (2nd version), 3) Regional deep seismic re-interpretation, and 4) Ocean-bottom seismograph velocity models.

  • 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.