From 1 - 10 / 630
  • Soil mapping at the local- (paddock), to continental-scale, may be improved through remote hyperspectral imaging of surface mineralogy. This opportunity is demonstrated for the semiarid Tick Hill test site (20 km2) near Mount Isa in western Queensland. The study of this test site is part of a larger Queensland government initiative involving the public delivery of 25,000 km2 of processed airborne hyperspectral mineral maps at 4.5 m pixel resolution to the mineral exploration industry. Some of the mineral maps derived from hyperspectral imagery for the Tick Hill area include the abundances and/or physicochemistries (chemical composition and crystal disorder) of dioctahedral clays (kaolin, illite-muscovite and Al smectite, both montmorillonite and beidellite), ferric/ferrous minerals (hematite/goethite, Fe2+-bearing silicates/carbonates) and hydrated silica (opal) as well as soil water (bound and unbound) and green and dry (cellulose/lignin) vegetation. Validation of these hyperspectral mineral products is based on field soil sampling and laboratory analyses (spectral reflectance, X-ray diffraction, scanning electron microscope and electron backscatter). The mineral maps show more detailed information regarding the surface composition compared with the published soil and geology (1:100,000 scale) maps and airborne radiometric imagery (collected at 200 m line spacing). This mineral information can be used to improve the published soil mapping but also has the potential to provide quantitative information suitable for soil and water catchment modeling and monitoring.

  • Bathurst NSW regolith-landforms map 1:250 000

  • Geoscience Australia has created a DVD 'Landsat Metadata Map Ups of Indonesia' for the Indonesian Ministry of Forestry (MoF). The DVD contains Landsat metadata information sourced from USGS and GISTDA for selected years based on the catalogue searches that Geoscience Australia has done to-date. This is one of the action items from the Bali Remote Sensing workshop in February 2009.

  • Displays the coverage of publicly available digital gamma-ray spectrometric data. The map legend is coloured according to the line spacing of the survey with broader line spacings (lower resolution surveys) displayed in shades of blue. Closer line spacings (higher resolution surveys are displayed in red, purple and coral.

  • The Leeuwin Current has significant ecological impact on the coastal and marine ecosystem of south-western Australia. This study investigated the spatial and temporal dynamics of the Leeuwin Current using monthly MODIS SST dataset between July 2002 and December 2012. Topographic Position Index layers were derived from the SST data for the mapping of the spatial structure of the Leeuwin Current. The semi-automatic classification process involves segmentation, 'seeds' growing and manual editing. The mapping results enabled us to quantitatively examine the current's spatial and temporal dynamics in structure, strength, cross-shelf movement and chlorophyll a characteristic. It was found that the Leeuwin Current exhibits complex spatial structure, with a number of meanders, offshoots and eddies developed from the current core along its flowing path. The Leeuwin Current has a clear seasonal cycle. During austral winter, the current locates closer to the coast (near shelf break), becomes stronger in strength and has higher chlorophyll a concentrations. While, during austral summer, the current moves offshore, reduces its strength and chlorophyll a concentrations. The Leeuwin Current also has notable inter-annual variation due to ENSO events. In El Niño years the current is likely to reduce strength, move further inshore and increase its chlorophyll a concentrations. The opposite occurs during the La Niña years. In addition, this study also demonstrated that the Leeuwin Current has a significantly positive influence over the regional nutrient characteristics during the winter and autumn seasons. Apart from surface cooling and advection, the Leeuwin Current's sizable cross-shelf movement may be another contributing factor to the seasonal and inter-annual variations of its chlorophyll a concentrations.

  • The eastern Yilgarn Craton (EYC) of Western Australia is Australia's premier gold and nickel province, and has been the focus of geological investigations for over a century. Geoscience Australia, in conjunction with partners in the Predictive Mineral Discovery Cooperative Research Centre conducted a series of projects between 2001 and 2008 (Y4 project team, 2008). This article summarises the highlights and new findings from the research, many of which challenge previous paradigms on the tectonics and architecture, as well as the relationship of gold to structure, magmatism and metamorphism. Although a Yilgarn-based study, the results have general implications for other Archaean terranes.

  • The product comprises digital outcrop geology and interpreted basement geology layers in ArcInfo, MapInfo and ArcView formats. The data were compiled from geological mapping of the Parkes 100K sheet from 1995 to 1998 by AGSO and the NSW Geological Survey under the NGMA. The data layers are a subset of the Forbes 250K sheet GIS data package.

  • The Harris Greenstone Belt in the central Gawler Craton of South Australia has potential for Archaean Ni-Cu-PGE sulphide and Archaean-Proterozoic lode-Au mineralising systems. This map is a preliminary interpretation of the Precambrian basement geology based on aeromagnetics, gravity, and diamond drilling. It highlights the extensive distribution of poorly exposed Archaean komatiites and associated rocks (green) that have a strike extent of at least 300 km. The regional pattern of linear komatiitic sequences associated with ovoid granitic plutons and province-wide shear systems, is very similar to the economically important Eastern Goldfields Province in the Yilgarn Craton, Western Australia. Related products <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=40975">Harris Greenstone Belt GIS Dataset</a> <a href="https://www.ga.gov.au/products/servlet/controller?event=GEOCAT_DETAILS&amp;catno=68362">Gawler Mineral Promotion: Preliminary assessment of the Ni-Cu-PGE potential of the Harris Greenstone Belt, Gawler Craton - PowerPoint</a>

  • Australian Copper Deposits, Occurrences and Potential as of February 2005

  • Australian Gold Resources Map, 1:10 000 000, June 2008 Version