Minerals replacement reactions: understanding mineral formation under hydrothermal conditions. Many geological processes involve the transformation of one mineral into another. By understanding molecular-level reaction mechanisms, we can predict how fast reactions progress, and what the final product will look like. This project focuses on a reaction mechanism called 'coupled dissolution-reprecipitation', in which the parent mineral is dissolved into a thin layer of fluid at the reaction front, ....Minerals replacement reactions: understanding mineral formation under hydrothermal conditions. Many geological processes involve the transformation of one mineral into another. By understanding molecular-level reaction mechanisms, we can predict how fast reactions progress, and what the final product will look like. This project focuses on a reaction mechanism called 'coupled dissolution-reprecipitation', in which the parent mineral is dissolved into a thin layer of fluid at the reaction front, and the daughter mineral subsequently precipitates. This concept will be applied to sulfide minerals for the first time. The results have many applications for the Australian mining industry, in particular in improving the efficiency of the processing of Ni- and Au-ores.Read moreRead less
An experimental study of trace element equilibria during metamorphism. The analytical methods and experimental data to be developed will enable an Australian team to become world leaders in determining pressures and temperatures of mineral growth that correspond to a range of depths and temperature gradients in the Earth tha t is wider than accessible previously. Obtaining this information from small zones within single grains will allow determination of rates of change, and give us a detailed p ....An experimental study of trace element equilibria during metamorphism. The analytical methods and experimental data to be developed will enable an Australian team to become world leaders in determining pressures and temperatures of mineral growth that correspond to a range of depths and temperature gradients in the Earth tha t is wider than accessible previously. Obtaining this information from small zones within single grains will allow determination of rates of change, and give us a detailed picture of how the host rock has evolved, even from very small samples. One application would be checking the origin of relatively common minerals for whether they could be associated with diamonds.Read moreRead less
Order-disorder behaviour in Bi-tellurides: a tool to monitor gold scavenging by Bi-Te melts. This project addresses a group of minerals (bismuth tellurides) that are often part of the exotic assemblages present in gold deposits, yet their potential to model the gold-forming processes is only recently apparent. These minerals also have the capacity to record their genetic history due to crystal modularity. Materials scientists target the analogous synthetic compounds because of the same structura ....Order-disorder behaviour in Bi-tellurides: a tool to monitor gold scavenging by Bi-Te melts. This project addresses a group of minerals (bismuth tellurides) that are often part of the exotic assemblages present in gold deposits, yet their potential to model the gold-forming processes is only recently apparent. These minerals also have the capacity to record their genetic history due to crystal modularity. Materials scientists target the analogous synthetic compounds because of the same structural modularity for applications in nanotechnology. The dataset on the mineral compounds, using the geological environment as a natural laboratory, will serve materials science research, as much as delivering key information relevant to understanding the reasons for gold enrichment in economically important types of ores. Read moreRead less
Water storage in the earth's mantle - understanding the process of OH incorporation in olivine. The amount of water in the Earth's mantle is thought to be sufficient to replace the surface oceans more than ten times. Whether this water exists in a fluid, melt, or mineral is important for understanding a range of mantle properties. The entire upper mantle water budget may be accommodated at defect sites in the mineral olivine. However, defects found in natural olivine do not correspond to thos ....Water storage in the earth's mantle - understanding the process of OH incorporation in olivine. The amount of water in the Earth's mantle is thought to be sufficient to replace the surface oceans more than ten times. Whether this water exists in a fluid, melt, or mineral is important for understanding a range of mantle properties. The entire upper mantle water budget may be accommodated at defect sites in the mineral olivine. However, defects found in natural olivine do not correspond to those produced
experimentally. Therefore, previous conclusions on water storage in the mantle are questionable. To address this problem the mechanism of water incorporation in olivine will be investigated using experimental petrology and spectroscopy.Read moreRead less
Experimental studies on hydrothermal reaction processes at the molecular level: the role of mineral replacement reactions in ore formation. Most of the World's supply of metals such as copper (Cu), gold (Au), molybdenum (Mo), lead (Pb), zinc (Zn) or uranium (U) comes from hydrothermal ore deposits. The metals were deposited deep below the Earth's surface when hot fluids, carrying minute quantities of the metals, reacted with suitable rocks to form ore minerals. By understanding molecular-level ....Experimental studies on hydrothermal reaction processes at the molecular level: the role of mineral replacement reactions in ore formation. Most of the World's supply of metals such as copper (Cu), gold (Au), molybdenum (Mo), lead (Pb), zinc (Zn) or uranium (U) comes from hydrothermal ore deposits. The metals were deposited deep below the Earth's surface when hot fluids, carrying minute quantities of the metals, reacted with suitable rocks to form ore minerals. By understanding molecular-level reaction mechanisms at high pressure and temperature, we can predict the nature of the ore minerals formed for a given set of physical and chemical conditions. This multidisciplinary research project is devoted to understanding these chemical and physical processes and how this knowledge can be applied to improve mineral exploration, mining, and ore processing.Read moreRead less
Advancing diamond exploration - novel techniques for the interpretation of indicator minerals. Diamond production is an important industry in Australia, with a total export value in 2004-05 of $650 million. Most of this production comes from the Argyle Mine in Western Australia, which may be nearing the end of its productivity. Therefore, there is a need to reinvigorate exploration for diamond in Australia, in order for new and significant deposits to be discovered. The outcomes of this proposal ....Advancing diamond exploration - novel techniques for the interpretation of indicator minerals. Diamond production is an important industry in Australia, with a total export value in 2004-05 of $650 million. Most of this production comes from the Argyle Mine in Western Australia, which may be nearing the end of its productivity. Therefore, there is a need to reinvigorate exploration for diamond in Australia, in order for new and significant deposits to be discovered. The outcomes of this proposal will provide diamond exploration companies with improved mineralogical tools to assess the likely diamond grade of parts of the lithosphere sampled by kimberlite or lamproite magmas, thus better directing exploration strategies.Read moreRead less
The role of melting of oceanic crust within the subduction factory: A melt inclusion approach. Continental crust is ultimately generated in subduction zones, where oceanic crust is recycled back into the mantle along deep ocean trenches, producing island arcs. Processes occurring in the subduction 'factory' are poorly understood, but dehydration of old subducted oceanic crust is usually invoked to provide water that triggers mantle melting and arc magmatism. Evidence is accumulating that in many ....The role of melting of oceanic crust within the subduction factory: A melt inclusion approach. Continental crust is ultimately generated in subduction zones, where oceanic crust is recycled back into the mantle along deep ocean trenches, producing island arcs. Processes occurring in the subduction 'factory' are poorly understood, but dehydration of old subducted oceanic crust is usually invoked to provide water that triggers mantle melting and arc magmatism. Evidence is accumulating that in many locations the subducted oceanic crust may melt, rather than simply dehydrate. I will test this using studies of melt inclusions (droplets of melt trapped by crystals growing in the magma), and will better constrain the input-output budgets of the subduction factory.Read moreRead less
Developing indicator minerals to geochemically fingerprint mineralized Fe oxide Cu-Au systems: a pilot study around the Ernest Henry Cu-Au mine. Fe oxide Cu-Au deposits represent some of the largest accumulations of economically extractable metal in the earth's crust. However, exploration has been largely ineffective over the last decade, and new methods for their delineation are required to deliver a step-change in the efficiency of exploration programs. The development of a mineral indicator s ....Developing indicator minerals to geochemically fingerprint mineralized Fe oxide Cu-Au systems: a pilot study around the Ernest Henry Cu-Au mine. Fe oxide Cu-Au deposits represent some of the largest accumulations of economically extractable metal in the earth's crust. However, exploration has been largely ineffective over the last decade, and new methods for their delineation are required to deliver a step-change in the efficiency of exploration programs. The development of a mineral indicator scheme to fingerprint potential ?ore-forming? systems using state-of-the-art laser ablation ICP-MS analysis may engender new methods and strategies that lead to exploration success. A baseline study around a known deposit provides the best means to characterize indicators- the Ernest Henry Cu-Au deposit provides the ideal candidate.Read moreRead less
Optimum control of the in-use performance of talc-based compositions. It is important to improve the quality of their Talcom body powder, baby powder and other cosmetic products involving talc. The areas that can and need to be improved are shining characteristics, assessing the slip properties as well as developing the cosmetic chemistry of talc and other additives. The proposed project will generate: a) simple but reliable test methods for measuring slip and shine, b) methods for control of t ....Optimum control of the in-use performance of talc-based compositions. It is important to improve the quality of their Talcom body powder, baby powder and other cosmetic products involving talc. The areas that can and need to be improved are shining characteristics, assessing the slip properties as well as developing the cosmetic chemistry of talc and other additives. The proposed project will generate: a) simple but reliable test methods for measuring slip and shine, b) methods for control of the physical and chemical characteristics of talc blends, c) mathematical model(s) for property and process control, which is useful to improvement of the final talc properties and in-use service.Read moreRead less
Transitions and Zoning in Porphyry-Epithermal Districts: Indicators, Discriminators, and Vectors. We aim to improve understanding of ore genesis and exploration success in porphyry-epithermal mineral districts. These districts can contain porphyry Cu-Mo-Au deposits (the world's major source of copper), epithermal Au-Ag deposits, skarn and sediment-hosted gold deposits. These districts continue to be important targets for copper and gold explorers, even though it can be difficult to identify th ....Transitions and Zoning in Porphyry-Epithermal Districts: Indicators, Discriminators, and Vectors. We aim to improve understanding of ore genesis and exploration success in porphyry-epithermal mineral districts. These districts can contain porphyry Cu-Mo-Au deposits (the world's major source of copper), epithermal Au-Ag deposits, skarn and sediment-hosted gold deposits. These districts continue to be important targets for copper and gold explorers, even though it can be difficult to identify the ore zones within large zones of background alteration. We will develop and test criteria that can be used by explorers to indicate prospective environments, discriminate between mineralization styles, and vector towards ore zones - be they of porphyry, epithermal, and/or other peripheral styles.Read moreRead less