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  • Australia's Large Igneous Provinces (LIPs) span most of Earth's geological history, ranging from Early Archean to Recent. LIPs in continental Australia are represented by continental flood basalts, fragments of oceanic plateaux, layered mafic-ultramafic intrusions, sill complexes and dyke swarms. It is only in the last decade that geologists have started to focus on LIPs in Australia, mainly from the perspective of their mineral potential, particularly after the discovery of the Nebo-Babel Ni-Cu-PGE deposit in the West Musgrave Province, central Australia. The list of LIPs increased by including other well-known igneous provinces, such as the Fortescue, Warakurna, Hart-Carson, Kalkarindji (formerly known as Antrim Plateau Volcanics) and various dyke swarms (e.g., Widgiemooltha, Marnda Moorn, Gairdner). The Bunbury Basalt, although only covering a small area in the Cape Naturaliste-Cape Leeuwin peninsula, joined the list of LIPs, due to its age links with the huge Kerguelen oceanic plateau magmatism. As indicated by the world-class Nebo-Babel deposit and further discoveries in the West Musgrave and in the Kimberley region, the mineral potential of LIPs is very high. In the case of orthomagmatic mineral systems, the selection of areas or specific intrusions requires focusing on isotope systematics and trace- and major-element geochemical trends to filter out mafic-ultramafic intrusions that may not have undergone sulphur saturation from those that have experienced sulphur saturation from processes, such as crustal contamination. In eastern Australia, there are two major volcanic provinces: the Early Cretaceous Whitsunday volcanic province, which is a good example of a silicic LIP, and a 4400 km long belt characterised by recent (youngest volcano is 4600 years ago) intraplate alkaline volcanism. The mineral potential associated with these provinces is as yet not fully assessed.

  • Extensive benefits and tools can be gained for mineral explorers, land-users and government and university researchers using new spectral data and processing techniques. Improved methods were produced as part of a large multi-agency project focusing on the world-class Mt Isa mineral province in Australia. New approaches for ASTER calibration using high-resolution HyMap imagery through to testing for compensation for atmospheric residuals, lichen and other vegetation cover effects have been included in this study. . Specialised data processing software capable of calibrating and processing terabytes of multi-scene imagery and a new approach to delivery of products, were developed to improve non-specialist user interpretation and comparison with other datasets within a GIS. Developments in processing and detailed reporting of methodology, accuracies and applications can make spectral data a more functional and valuable tool for users of remote sensing data. A highly-calibrated approach to data processing, using PIMA ground samples to validate the HyMap, and then calibrating the ASTER data with the HyMap, allows products to have more detailed reliable accuracies and integration with other data, such as geophysical and regolith information in a GIS package, means new assessments and interpretations can be made in mapping and characterising materials at the surface. Previously undiscovered or masked surface expression of underlying materials, such as ore-deposits, can also be identified using these methods. Maps and products made for this project, covering some ~150 ASTER scenes and over 200 HyMap flight-lines, provide a ready-to-use tool that aids explorers in identifying and mapping unconsolidated regolith material and underlying bedrock and alteration mineralogy.

  • The most important known deposits of what are commonly referred to as the beach sand minerals are situated along the most easterly part of the Australian coast. The geographical distribution, physiography, formation, origin, composition, and reserves of heavy minerals along the east coast are discussed in this report.

  • Two methods are outlined in this report. The first, is a method intended for the determination of porosity of consolidated sediments. The method is applicable to those sediments included in rotary drill cores and hand specimens of rock collected in the field. The second, is a method intended for the determination of permeability. It is applicable to suitably sized samples of rocks and any other substances whose constitutions permit of their being treated by the procedure set out in this method, subject to their own inherent limitations relative to this method. This report provides a detailed description of each of these methods.

  • The deposits of heavy mineral sands along the East Coast of Australia are being investigated primarily to determine their content of monazite. These deposits contain most of the known world reserves of zircon and rutile for which they are being exploited at various localities. Monazite, a phosphate of cerium, lanthanum, praseodymium and other rare earths, with thorium silicate, is utilised commercially as a source of cerium and of thorium. In this investigation, the thorium content on the monazite is being determined on the basis of its radioactivity. Two deposits in the Tweed-Fingal area were examined. The geology of the area, methods of testing, and the results of the investigation are discussed in this report.

  • The deposits of heavy mineral sands along the East Coast of Australia are being investigated primarily to determine their content of monazite. These deposits contain most of the known world reserves of zircon and rutile for which they are being exploited at various localities. Monazite, a phosphate of cerium, lanthanum, praseodymium and other rare earths, with thorium silicate, is utilised commercially as a source of cerium and of thorium. In this investigation, the thorium content on the monazite is being determined on the basis of its radioactivity. A principal deposit, and two smaller deposits, in the Fingal-Cudgen area were investigated. The geology of the area, methods of testing, and the results of the investigation are discussed in this report.

  • In 1946 and 1947 the writer had excellent opportunities to study the effect of lateritisation in the course of geological reconnaissances in Northern Australia. From field evidence which has been collected on several aspects of lateritisation - origin, products and relationship to geomorphological processes - a detailed account of lateritisation in Australia can be given. Lateritisation and the occurrence of opal are discussed in this report.

  • A number of Paleoproterozoic layered mafic-ultramafic intrusions in the central part of the Halls Creek Orogen of East Kimberley, Western Australia, have been explored for platinum-group elements (PGE), chromium, nickel, copper, cobalt and gold. Here we report on the halogen geochemistry of apatite and biotite in a number of these intrusions. Interstitial apatite is ubiquitous in these intrusions and, in most samples, tends to be relatively enriched in F- and OH-endmembers and relatively poor in Cl (< 20 mole %). Fluorapatite occurs in the more evolved igneous rocks and in marginal samples that apparently have been contaminated by metamorphic country rock. Cl/F ratios generally increase with bulk rock molar Mg/(Mg + Fe) ratios, as observed in other intrusions. Only a few samples show Cl-enrichment as high as that seen in the Stillwater and Bushveld complexes beneath the major stratabound PGE deposits. The most Cl-rich compositions observed occur in the upper part of the Springvale intrusion, where it is associated with troctolite, and in a single sample from the McIntosh intrusion. For the former intrusion, it is suggested that volatiles migrating out of the lower part of the mafic stratigraphy stabilized olivine at the expense of pyroxene. Associated biotite tends to be low in both Cl and F, containing no more than 10 mole % of these components. It is concluded that the East Kimberley intrusions contained a low to moderate volatile component that, during the combined processes of crystallization, degassing and fractionation of interstitial halogen-bearing minerals, was able to produce a late, mobile interstitial silicate liquid or volatile-rich fluid phase of variable Cl/F content that gave rise to most of the observed variations within any given intrusion. The exceptions include some marginal samples that appear to have been affected by country rocks, either during emplacement (assimilation) or during later metamorphism. The generally low Cl/F ratio of apatite, the lack of primary amphibole and the high background sulfur concentrations of the East Kimberley intrusions suggest that these magmas were relatively dry. The possible development of high-grade, PGE-enriched horizons by late-stage hydrothermal processes that could have mobilized significant amounts of the PGE and sulfur is considered to be of low potential.