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  • This two year collaborative project was established in July 2006 with the overall aim of developing, validating, evaluating and delivering a suite of publicly available, pre-competitive mineral mapping products from airborne HyMap hyperspectral imagery and satellite multispectral ASTER imagery. Moreover, it was important to establish whether these mineral maps would complement other precompetitive geological and geophysical data and provide valuable new information regards enhanced mineral exploration for industry. A mineral systems approach was used to appreciate the value of these mineral maps for exploration. That is, unlocking the value from these mineral maps is not simply by looking for the red bulls-eyes. Instead, mineral products need to be selected on the basis of critical parameters, such as what minerals are expected to develop as fluids migrate from source rocks to depositional sites and then into outflow zones with each associated with different physicochemical conditions (e.g. metasomatic metal budget, nature of the fluids, water-rock ratios, lithostatic pressure, pore fluid pressure, REDOX, pH, and temperature). One of the other key messages is to be able to recognise mineral chemical gradients as well as anomalous cross-cutting effects. These principles were tested using a number of case histories including, (1) the Starra iron oxide Cu-Au deposit; (2) the Mount Isa Pb-Zn-Ag and Cu deposits; and (3) Century Zn, all within the Mount Isa Block. These showed that the interpreted mineral alteration footprints of these mineral systems can be traced 10-15 km away from the metal deposition sites. In summary this project has shown that it is possible to generate accurate, large area mineral maps that provide new information about mineral system footprints not seen in other precompetitive geoscience data and that the vision of a mineral map of Australia is achievable and valuable.

  • B6/B5 (potential includes: pyrophyllite, alunite, well-ordered kaolinite) Blue is low content, Red is high content Useful for mapping: (1) different clay-type stratigraphic horizons; (2) lithology-overprinting hydrothermal alteration, e.g. high sulphidation, "advanced argillic" alteration comprising pyrophyllite, alunite, kaolinite/dickite; and (3) well-ordered kaolinite (warmer colours) versus poorly-ordered kaolinite (cooler colours) which can be used for mapping in situ versus transported materials, respectively.

  • 1. Band ratio: B7/B8 Blue-cyan is magnesite-dolomite, amphibole, chlorite Red is calcite, epidote, amphibole useful for mapping: (1) exposed parent material persisting through "cover"; (2) "dolomitization" alteration in carbonates - combine with Ferrous iron in MgOH product to help separate dolomite versus ankerite; (3) lithology-cutting hydrothermal (e.g. propyllitic) alteration - combine with FeOH content product and ferrous iron in Mg-OH to isolate chlorite from actinolite versus talc versus epidote; and (4) layering within mafic/ultramafic intrusives. useful for mapping: (1) exposed parent material persisting through "cover"; (2) "dolomitization" alteration in carbonates - combine with Ferrous iron in MgOH product to help separate dolomite versus ankerite; (3) lithology-cutting hydrothermal (e.g. propyllitic) alteration - combine with FeOH content product and ferrous iron in Mg-OH to isolate chlorite from actinolite versus talc versus epidote; and (4) layering within mafic/ultramafic intrusives. useful for mapping: (1) exposed parent material persisting through "cover"; (2) "dolomitization" alteration in carbonates - combine with Ferrous iron in MgOH product to help separate dolomite versus ankerite; (3) lithology-cutting hydrothermal (e.g. propyllitic) alteration - combine with FeOH content product and ferrous iron in Mg-OH to isolate chlorite from actinolite versus talc versus epidote; and (4) layering within mafic/ultramafic intrusives.

  • 1. 3 band RGB composite Red: B3/B2 Green: B3/B7 Blue: B4/B7 (white = green vegetation) Use this image to help interpret (1) the amount of green vegetation cover (appears as white); (2) basic spectral separation (colour) between different regolith and geological units and regions/provinces; and (3) evidence for unmasked cloud (appears as green).

  • Band ratio: B3/B2 Blue is low content Red is high content Use this image to help interpret the amount of "obscuring/complicating" green vegetation cover.

  • This is a 2D animation created in After Effects. It is a stand-alone animation of the beam operation in the Sensitive High Resolution Ion Microprobe (SHRIMP), in GA. This 2D animation is based on the 3D model shown in the SHRIMP movie (GeoCat No. 65756).

  • 1. Band ratio: (B6+B9/(B7+B8) Blue is low content, Red is high content (potentially includes: calcite, dolomite, magnesite, chlorite, epidote, amphibole, talc, serpentine) Useful for mapping: (1) "hydrated" ferromagnesian rocks rich in OH-bearing tri-octahedral silicates like actinolite, serpentine, chlorite and talc; (2) carbonate-rich rocks, including shelf (palaeo-reef) and valley carbonates(calcretes, dolocretes and magnecretes); and (3) lithology-overprinting hydrothermal alteration, e.g. "propyllitic alteration" comprising chlorite, amphibole and carbonate. The nature (composition) of the silicate or carbonate mineral can be further assessed using the MgOH composition product.

  • A world-first continental-scale mosaic of multi-spectral ASTER (Advanced Spaceborne Thermal Emission and Reflectance Radiometer) data is to be delivered for the Australian continent in 2012. ASTER data has improved spectral resolution compared with landsat TM and is providing a wealth of new national information on surface mineralogy, geochemistry and landform characteristics and composition. The new continental mineral maps can be readily combined with other geoscientific datasets and have applications in regolith-landform mapping, mineral exploration, geohazard research and impact analysis, as well as agriculture and land-use planning. Using satellite multispectral ASTER to map material on the surface of the Earth at a continental scale is the next step in delivering environmental, agricultural and resource exploration tools for users of remote sensing and GIS. Mapping mineral group information using targeted band combinations can find previously unmapped outcrop of bedrock, help define soil type and chemistry, and delineate and characterise regolith and landform boundaries over large and remote areas.