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  • The cartographic collection of the Doc Fisher Geoscience Library consists of the maps and air photos created or acquired by agency staff since the formation of BMR in 1946. This includes maps produced by agencies which have merged with these over the years, such as AUSLIG. Maps held include: Australian geological map series (1:250,000, 1:100,000 and the 1 mile series); topographic maps produced by NATMAP and its predecessors (1:250,000, 1:100,000 and 1:50,000) - latest editions only; various Australian geochemical, geophysical and other thematic maps; geoscience map series from other countries acquired on an exchange basis, including some with accompanying explanatory notes; Non-series maps acquired by donation or exchange; atlases. The Air photos are predominantly those used for mapping Australia and, to a lesser extent, Papua New Guinea and Antarctica, by BMR/AGSO from the 1940s to the 1980s. Geographical coverage of the sets is not complete, but many individual photos are unique in that they have pin points, overlays or other markings made by teams in the field. The Papua New Guinea photographs in the collection may, in many cases, be the only existing copies. Flight diagrams are also held for many (but not all) sets of air photos. Some other related materials, such as montages of aerial photographs (orthophotos), are also represented in the collection.

  • The ENE-trending Mallina Basin developed in the central part of the Pilbara Craton, NW Australia, between c. 3010 and 2940 Ma, over the boundary between two distinct terrains characterised by greenstones aged c. 3120 and older. The basin preserves an association of igneous rocks characterised by an unusual combination of high-Mg and high LILE concentrations, that provides valuable insight into the geological evolution of the region. The oldest dated components of the Mallina Basin are c. 3010 Ma volcaniclastic rocks found only in the far northwest. Geochronology and field relationships indicate that the main basin deposition, of clastic rocks, occurred from 2970 to 2955 Ma. Towards the end of this depositional phase, siliceous high-Mg basalts (SHMB) formed the upper part of the stratigraphy in the northwestern part of the basin (Whim Creek Belt), and their subvolcanic equivalents intruded the southern part of the basin. Sedimentation was terminated by ESE?WNW compression at c. 2955-2950 Ma. Rocks with boninitic compositions and spatially associated low-Ti tholeiitic gabbro formed sub-volcanic sills in coarse siliciclastic rocks in the southern part of the basin, probably during the waning stages of compression. Immediately after compression, an extensive alkaline granite complex was emplaced into the central and northern part of the basin, coeval with intrusion of a 2955-2945 Ma high-Mg diorite (or sanukitoid) suite. Renewed extension also resulted in renewed basin sedimentation between 2945 and 2935 Ma. Voluminous high-K monzogranite swamped the region between c. 2935 and 2930 Ma, particularly adjacent to, and south of the basin, and was early- to syn-tectonic with respect to SE-NW compression. Monzogranite magmatism becomes systematically younger and less voluminous away from the Mallina Basin.

  • This data package comprises data sets which cover the Tallangatta 1:250 000 map sheet (TALLANGATTA). This area has recently been covered by airborne geophysical surveys by the Geological Survey of Victoria and these data sets intend to compliment this data.

  • This summary report outlines the key findings of the study. Full details of the methodology and all findings of the study, including limitations and assumptions, are provided in the companion technical report.

  • Legacy product - no abstract available

  • The geochemical map (copy attached) prepared by Mt.I sa Mines Ltd., has been compared with plans showing the self-potential and electromagnetic results of the geophysical survey carried out at the Labour Victory Mine, near Selwyn, Queensland in 1952 and 1953. (Plates 4 and 7 of B.M.R Records 1954, No. 2). Transparencies of these two plates are also attached.

  • The calcrete dataset, compiled from 23 sources by PIRSA, was assessed to determine whether such a dataset could be used for baseline geochemical studies. The database has 162,524 entries and lacks important information on calcrete type, sample location, analytical methods. It has a limited suite of geochemical analyses (Ag, As, Au, Ca, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb & Zn) such that mass balances cannot be done to determine the integrity of the data. Only 80% of the data have Ca geochemistry and it appears as though high Au does not necessarily correspond to high Ca suggesting that some of the samples unlikely to be pure calcrete by definition and probably contain other components such as lithic fragments, gypsum, dolomite or gangue materials. There are significant issues with detection limits relating to the gold assay results and although reported as ppb it is difficult to determine whether those samples below 0.2 are ppb or in fact ppm. Some of the Ca values reported have more Ca than pure calcite which is improbable given the sampling conditions. For the reasons stated above and calcretes limited distribution within Australia this dataset, and calcrete sampling in general, is unsuitable for baseline geochemical purposes. Before it is used for any other purposes, the dataset needs to be reassessed and time spent on quality control. If a unified approach to sampling was adopted then its suitability as a sampling medium for mineral exploration would improve.

  • Geoscience Australia and the Cooperative Research Centre for Landscape Environments and Mineral Exploration (CRC LEME), in collaboration with State agencies are conducting a series of pilot baseline geochemical surveys (BGS). These surveys are intended to characterise regional geochemical patterns and are contributing to what is presently a limited research direction in Australia. BGS provide valuable information about the state of the environment and can assist in (1) establishing baselines to monitor future change; (2) targeting mineral exploration; (3) developing informed environmental policies; and (4) geomedical studies on plant and animal well-being. In 2004-05, sampling at an average sampling density of one sample per 1100 km2,was conducted in the Gawler Craton, South Australia. In contrast to our first pilot region in the Riverina of New South W ales and Victoria, the Gawler region lacks well developed drainage systems, with the western portion being dominated by aeolian dunes. One of the key aims of the Gawler study is to determine whether element excesses or deficiencies exist in the regolith, and the implications of these for plant, animal and human health. Top (0-10 cm depth) and bottom (10 cm from ~55-90 cm depth) sediment samples were collected in the lower parts of 42 catchments. The composition of the <75 um and <180 um fractions were analysed for total major and trace elements using XRF (major and some trace elements), ICP-MS (most trace elements) and ISE (F) methods. Preliminary results show that F, Cr and V are locally elevated above national and international guideline concentrations, raising concerns that these elements may pose potential health issues. Heavy mineral fractions (density >2.95) in 6 samples (3 sites) are dominated by iron oxides (hematite, magnetite, goethite), spinels (ilmenite, spinel), rutile, zircon and barite. Some Cr and V may be associated with heavy minerals such as spinels, limiting their bioavailability. Cu, Se and Zn are potentially deficient in parts of the region, but once identified in agricultural areas can easily be remedied through the application of appropriate fertilizers. Dispersion of elements in the region appear to be at the catchment scale. The pilot studies conducted highlight the need for more comprehensive national guidelines for the assessment of elements in the natural environment. Results from this study are based on total elemental concentrations, and do not account for bioavailability, which plays an important role in assessment of geochemical hazards. However, assessment of baseline regional geochemical trends greatly assists in focusing more detailed research.