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  • Trace Energy Services was contracted by ANSIR to conduct the ANSTO 2002 Seismic Survey in New South Wales. Raw data for this survey are available on request from clientservices@ga.gov.au

  • Gibson G. M., Murphy B., Henson P. & Barlow M. 2004. Basement controlled basin architecture and fault geometries in the Mount Isa Western Succession. SEG 2004: Predictive Mineral Discovery Under Cover; extended abstracts. Centre for Global Metallogeny, University of Western Australia Publication, 33, p.419.

  • Project Y2 Appendix 2_16 Rock Properties database

  • This dataset contains polygon cadastral data and non-spatial attribute data for the Cocos (Keeling) Islands. Horsburgh Island and North Keeling Atoll are not included in this dataset.

  • Recent field observations have identified the widespread occurrence of fluid seepage through the eastern Mediterranean Sea floor in association with mud volcanism or along deep faults. Gas hydrates and methane seeps are frequently found in cold seep areas and were anticipated targets of the MEDINAUT/MEDINETH initiatives. The study presented herein has utilized a multi-disciplinary approach incorporating observations and sampling of visually selected sites by the manned submersible Nautile and by ship-based sediment coring and geophysical surveys. The study focuses on the biogeochemical and ecological processes and conditions related to methane seepage, especially the anaerobic oxidation of methane (AOM), associated with ascending fluids on Kazan mud volcano in the eastern Mediterranean. Sampling of adjacent box cores for studies on the microbiology, biomarkers, pore water and solid phase geochemistry allowed us to integrate different biogeochemical data within a spatially highly heterogeneous system. Geophysical results clearly indicate the spatial heterogeneity of mud volcano environments. Results from pore water geochemistry and modeling efforts indicate that the rate of AOM is 6 mol m-2 year-1, which is lower than at active seep sites associated with conditions of focused flow, but greater than diffusion-dominated sites. Furthermore, under the non-focused flow conditions at Kazan mud volcano advective flow velocities are of the order of a few centimeters per year and gas hydrate formation is predicted to occur at a sediment depth of about 2 m and below. The methane flux through these sediments supports a large and diverse community of micro- and macrobiota, as demonstrated by carbon isotopic measurements on bulk organic matter, authigenic carbonates, specific biomarker compounds, and macrofaunal tissues...

  • Legacy product - no abstract available

  • The established deformation paradigm for the Eastern Yilgarn Craton (EYC) has largely been developed from observations of overprinting relationships in the greenstone belts (Swager, 1989, 1997; Swager et al., 1992; Williams, 1993). Broadly, the recognised deformation (compressional history) involved early D1 recumbent folding and thrusting during N-S shortening, followed by E-W shortening through large-scale upright D2 folding and thrusting, then a period of strike-slip D3 faulting with associated folding, followed by continued regional D4 transpressive oblique and reverse faulting. Some authors have proposed early, intermediate, and late periods of extension throughout parts of this compressive history (Table 1). This study is aimed at providing a new deformation framework for the granites of the EYC. Granites form >60% of the surface expression of the province, so a more thorough understanding of their tectonic history is critical to our understanding of the evolution of the province. There are advantages of using deformed granites for establishing a time-space-event history. Granites have: 1. a well defined chrono-chemical framework across the entire province (pseudo-stratigraphy) (Champion & Sheraton, 1997); 2. a ductile mineralogy of quartz and feldspar that readily 'accepts' deformation; 3. multiple phases of granite, as sheets and dykes, which provide excellent markers for defining the subtleties of many of the events (especially the later ones); 4. exposure at various structural levels in the upper crust; and 5. a good U-Pb zircon geochronological database as a reference framework (Nelson, 1997; Fletcher, et al., 2001; Dunphy et al., 2003; Black et al., 2004). The scope of the study is to systematically describe the overprinting relationships of structures in granites for a range of structural levels and geographical positions (sites) for the major structural domains or terranes (Southern Cross, Kalgoorlie, Gindalbi-Kurnalpi-Laverton, and Merolia). The area chosen was the central EYC exposed in the area of the 1:250 000 scale map sheets of Leonora, Laverton, Menzies and Edjudina. This study area was chosen because new solid geology mapping (Whitaker and Blewett; 2002), new seismic reflection profiling (Goleby et al., 2002), and the available comprehensive geochronological database. The area also provided a different perspective for the regional deformation history to that determined from the better studied Kalgoorlie region (Swager, 1989). The approach was to systematically study the various structural elements for a range granite ages, with the granite age to be used as a time marker at each site. At each site, the structural elements before (cut by the dated phase) and after (overprint the dated phase) were systematically mapped and described. These structural elements form the data (available as separate data sheets) that were used to correlate events with adjacent sites in the same domain. These domain-wide event histories were also correlated to construct a new EYC deformation framework. Each stage of correlation becomes more interpretative. However, the original site data have been 'preserved' for evaluation and further testing.

  • During 2001 Geoscience Australia operated geomagnetic observatories at Alice Springs and Kakadu in the Northern Territory, Canberra in the Australian Capital Territory, Charters Towers in Queensland, Gnangara and Learmonth in Western Australia, Macquarie Island, Tasmania, in the sub-Antarctic, and Mawson in the Australian Antarctic Territory. Magnetic recording also took place at the stations of Casey and Davis in the Australian Antarctic Territory. This report describes instrumentation and activities, and presents monthly and annual mean magnetic values, plots of hourly mean magnetic values and K indices at the magnetic observatories and repeat stations operated by GA during calendar year 2001.

  • Yilgarn PDT Meeting, Perth, November 2004.

  • A1 talk, SEG 2004 Meeting, Perth, September 2004.