Raman spectroscopy has been an invaluable method for the non-destructive analysis of fluid inclusions for over 30 years1 and since then it has also been applied to the study of melt inclusions2. While the analysis of gas species in these inclusions is relatively straight forward, the identification of stable and metastable solid phases in inclusions is more challenging due to the limited availability of reference Raman spectra for some minerals. Some examples of inclusions with challenging Raman spectra are discussed below.

Regolith materials spatially and chemically associated with various types of ore deposits, such as iron oxides, manganese oxides and gold deposits for example, have the potential to be mapped and characterised using remote sensing techniques. With the release of new state-scale multispectral data such as the Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) Geoscience map of Western Australia (Figure 1), these applications may be tested and evaluated, along with identifying ore deposit types and characteristics best suited to using remote sensing techniques. A world-first continental scale ASTER mosaic and pre-competitive geoscience products for Australia are planned for public release in August 2012. The ASTER products are designed to provide broad scale mineral group information for mineral explorers at the continental to prospect scale. The product will be particularly useful for obtaining information on remote or difficult to access areas of Australia. ASTER data consists of 14 bands from Visible and Near Infrared (VNIR) light, through Short Wave Infrared (SWIR) and Thermal Infrared (TIR) encompassing different reflectance and emission spectras from the top few microns of material on the Earth's surface (Figure 2).

Using geophysical-geochemical spatial data to map of hydrothermal footprints in the Eastern Fold Belt of the Mount Isa Inlier

Iron (Fe) oxide mineralogy in most Australian soils is poorly characterised, even though Fe oxides play an important role in soil function. Fe oxides reflect the conditions of pH, redox potential (Eh), moisture and temperature in the soil environment. The Fe oxide mineralogy exerts a strong control on soil colour. Visible-near infrared (vis-NIR) spectroscopy can be used to identify and measure the abundance of certain Fe oxides in soil as well as soil colour. The aims of this paper are to: (i) measure the hematite and goethite content of Australian soils from their vis-NIR spectra, (ii) compare these results to measurements of soil colour, and (iii) describe the spatial variability of hematite, goethite and soil colour, and map their distribution across Australia. The spectra of 4606 surface soil sample from across Australia were measured using a vis-NIR spectrometer with a wavelength range between 350-2500 nm. We determined the Fe oxide content from characteristic absorptions of hematite (near 880 nm) and goethite (near 920 nm) and derived a normalised iron oxide difference index (NIODI) to better discriminate between them. The NIODI was generalised across Australia with its spatial uncertainty using sequential indicator simulation. We also derived soil RGB colour from the spectra and mapped its distribution and uncertainty across the country using sequential Gaussian simulations. The simulated RGB colour values were made into a composite true colour image and were also converted to Munsell hue, value and chroma. These colour maps were compared to the map of the NIODI and both were used for interpretation of our results. The work presented here was evaluated using existing studies on the distribution of Fe oxides in Australian soils.

Identifying and mapping regolith materials at the regional and continental-scale can be facilitated via a new generation of remote sensing methods and standardised geoscience products. The multispectral Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) is the first Earth observation (EO) system to acquire complete coverage of the Australian continent. The Japanese ASTER instrument is housed onboard the USA's Terra satellite, and has 14 spectral bands spanning the visible and near-infrared (VNIR - 500-1,000 nm - 3 bands @ 15 m pixel resolution); shortwave-infrared (SWIR - 1,000-2,500 nm range - 6 bands @ 30 m pixel resolution); and thermal infrared (TIR 8,000-12,000 nm - 90 m pixel resolution) with a 60 km swath. Although ASTER spectral bands do not have sufficient spectral resolution to accurately map the often small diagnostic absorption features of specific mineral species, which can be measured using more expensive 'hyperspectral' systems, current coverage of hyperspectral data is very restricted. The extensive coverage and 30m pixel size of ASTER make it well suited to national scale work. The spectral resolution of ASTER make it best suited to mapping broader 'mineral groups', such as the di-octahedral 'Al-OH' group comprising the mineral sub-groups (and their minerals species) like kaolins (e.g. kaolinite, dickite, halloysite), white micas (e.g. illite, muscovite, paragonite) and smectites (e.g. montmorillonite and beidellite). Extracting mineral group information using ASTER, using specially targeted band combinations, can find previously unmapped outcrop of bedrocks, weathering products, help define soil type and chemistry, and delineate and characterise regolith and landform boundaries over large and remote areas.

Report on the method and findings of the beach sands investigation in the area between ML180 and DC22, Broadbeach to North Burleigh. Estimates of the quantities and grades of heavy mineral concentrates, the quantities of overburden, and the quantities of each of the heavy minerals are tabulated.

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.

Samples of "glauconite" were collected from the glauconitic sandstone at Lakes Entrance and the glauconitic fossiliferous Miocene limestone of Maslin's Beach and Hackham. The refractive indices of the samples were measured. The results were compared against the range of refractive indices for glauconite, as given by A.N. Winchell. The composition of the samples and the observed results are discussed in this report.

The use of airborne hyperspectral imagery for mapping soil surface mineralogy is examined for the semi-arid Tick Hill test site (20 km2) near Mount Isa in north-western Queensland. Mineral maps at 4.5 m pixel resolution include the abundances and physicochemistries (chemical composition and crystal disorder) of kaolin, illite-muscovite, and Al smectite (both montmorillonite and beidellite), as well as iron oxide, hydrated silica (opal), and soil/rock water (bound and unbound). Validation of these hyperspectral mineral maps involved field sampling (34 sites) and laboratory analyses (spectral reflectance and X-ray diffraction). The field spectral data were processed for their mineral information content the same way as the airborne HyMap data processing. The results showed significant spatial and statistical correlation. The mineral maps provide more detailed surface compositional information compared with the published soil and geology maps and other geoscience data (airborne radiometrics and digital elevation model). However, there is no apparent correlation between the published soil types (i.e. Ferrosols, Vertosols, and Tenosols) and the hyperspectral mineral maps (e.g. iron oxide-rich areas are not mapped as Ferrosols and smectite-rich areas are not mapped as Vertosols). This lack of correlation is interpreted to be related to the current lack of spatially comprehensive mineralogy for existing regional soil mapping. If correct, then this new, quantitative mineral mapping data has the potential to improve not just soil mapping but also soil and water catchment monitoring and modeling at local to regional scales. The challenges to achieving this outcome include gaining access to continental-scale hyperspectral data and models that link the surface mineralogy to subsurface soil characteristics/processes.

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.