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
Low-grade metamorphic phosphate geochronology: High-precision dating of ancient crustal fluid flow, hydrothermal mineralisation and the "Great Oxidation Event". Reliable dating techniques are required to obtain precise ages for ancient crustal fluid flow. Current techniques suffer from inheritance and isotopic resetting, problems that are particularly pronounced in early Precambrian rocks. This project will employ new analytical techniques to date phosphate minerals recently identified as potent ....Low-grade metamorphic phosphate geochronology: High-precision dating of ancient crustal fluid flow, hydrothermal mineralisation and the "Great Oxidation Event". Reliable dating techniques are required to obtain precise ages for ancient crustal fluid flow. Current techniques suffer from inheritance and isotopic resetting, problems that are particularly pronounced in early Precambrian rocks. This project will employ new analytical techniques to date phosphate minerals recently identified as potentially important new chronometers of ancient fluid flow, providing the first precise tectonothermal history of the Archaean Pilbara Craton. The project will also establish the age of giant iron-ore deposits across the Hamersley Province, test the various models for iron-ore formation, and provide a minimum age for the oxidation of the Earth's surface. Read moreRead less
Olympic Dam in a Test Tube: Critical Experiments and Theory for Understanding Fe-Cu-U-REE in Hydrothermal Fluids and during Fluid-Rock Interaction. Olympic Dam (OD) is a supergiant Cu-U-Au-Ag-REE ore deposit, containing more than a trillion Australian dollars worth of metals, and hosted by hematite-rich breccia in South Australia. Yet, key aspects of the geochemistry of OD-style deposits remain poorly understood. This project will conduct innovative experiments to address the role for fluorine i ....Olympic Dam in a Test Tube: Critical Experiments and Theory for Understanding Fe-Cu-U-REE in Hydrothermal Fluids and during Fluid-Rock Interaction. Olympic Dam (OD) is a supergiant Cu-U-Au-Ag-REE ore deposit, containing more than a trillion Australian dollars worth of metals, and hosted by hematite-rich breccia in South Australia. Yet, key aspects of the geochemistry of OD-style deposits remain poorly understood. This project will conduct innovative experiments to address the role for fluorine in Fe, U and REE transport at OD, and the role of fluid-rock interaction in generating the unusually oxidised Fe-Cu mineral assemblages and in controlling U grades and distribution. The fundamental information gained will underpin intense on-going research aimed at discovering new OD-style orebodies and at creating new ore-processing technology that are environmentally sustainable and able to access lower-grade ores.Read moreRead less
Cracking the sulfate isotopic composition problem in ancient hydrothermal systems: application of the Carbonate-Associated Sulfate (CAS) method. Successful exploration of the deep Earth for valuable ores requires better knowledge of ore formation conditions, to feed to predictive deposit models. Our work shows great promise of improving the quality of this raw data. Smarter ore deposit prediction would likely exert its influence over the next ten years, rather than be immediate. It will increase ....Cracking the sulfate isotopic composition problem in ancient hydrothermal systems: application of the Carbonate-Associated Sulfate (CAS) method. Successful exploration of the deep Earth for valuable ores requires better knowledge of ore formation conditions, to feed to predictive deposit models. Our work shows great promise of improving the quality of this raw data. Smarter ore deposit prediction would likely exert its influence over the next ten years, rather than be immediate. It will increase exploration efficiency, saving tens of millions of dollars currently devoted to unproductive exploration. Exploration and mining are conducted primarily in regional Australia, and a healthy mining industry is therefore directly benefits hinterland communities. It also benefits all Australians through the payment of royalties and contributions to Australia's GDP from mineral exports.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
Continents in the Mantle Transition Zone? Sediment Recycling and the Geochemical Fertilization of the Deep Mantle. Because of its intrinsic compositional buoyancy, continental crust has traditionally been considered to be unsubductable in the denser underlying mantle. Yet some ocean island basalts carry a geochemical signature of recycled continental material in their plume source in the deep mantle. This project will reconcile this paradox through high-pressure experiments that will simulate su ....Continents in the Mantle Transition Zone? Sediment Recycling and the Geochemical Fertilization of the Deep Mantle. Because of its intrinsic compositional buoyancy, continental crust has traditionally been considered to be unsubductable in the denser underlying mantle. Yet some ocean island basalts carry a geochemical signature of recycled continental material in their plume source in the deep mantle. This project will reconcile this paradox through high-pressure experiments that will simulate subduction of continental sediments into the deep mantle. These experiments will provide the first empirical constraints on the role of sediment-derived fluids in mantle metasomatism and the origin of economically-rich potassic magmas, and the nature of the ultrarefractory continental component that ultimately reaches the plume source for ocean-island basalts.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
Sulfide Partial Melting at Broken Hill: Process and Implications. Based entirely on experimental studies, we suggested that the sulfide ore at Broken Hill, N.S.W., partially melted during granulite-facies metamorphism. Our subsequent discovery of sulfide melt inclusions in silicates associated with the ore strongly supports this assertion. This proposed research will evaluate the extent of melting and the composition of such a melt as well as the effect of this melt on the rocks surrounding the ....Sulfide Partial Melting at Broken Hill: Process and Implications. Based entirely on experimental studies, we suggested that the sulfide ore at Broken Hill, N.S.W., partially melted during granulite-facies metamorphism. Our subsequent discovery of sulfide melt inclusions in silicates associated with the ore strongly supports this assertion. This proposed research will evaluate the extent of melting and the composition of such a melt as well as the effect of this melt on the rocks surrounding the ore. The results of this basic research will not only impact on Broken Hill genetic models specifically, but could profoundly effect our understanding of metamorphic and magmatic sulfide deposits globally.Read moreRead less
Biosphere, hydrocarbon and ore fluid interactions in the Early Precambrian. Ore deposits and petroleum are important for economic and social areas of Australia's growth. New discoveries are needed to maintain Australia's wealth as mines reach the end of operations and petroleum supplies decrease. This project will demonstrate how ore fluids and hydrocarbons interact in the geological environment. It should, therefore greatly expand the conceptual framework in which to explore for both mineral an ....Biosphere, hydrocarbon and ore fluid interactions in the Early Precambrian. Ore deposits and petroleum are important for economic and social areas of Australia's growth. New discoveries are needed to maintain Australia's wealth as mines reach the end of operations and petroleum supplies decrease. This project will demonstrate how ore fluids and hydrocarbons interact in the geological environment. It should, therefore greatly expand the conceptual framework in which to explore for both mineral and hydrocarbon resources, particularly in old, deep and hot basins, which are considered to be the last frontiers of exploration. Outcomes concerning the nature of early life will be of global interest.Read moreRead less
Modeling fluid flow and mineralisation at crustal interfaces. Several types of mineral resources, including some uranium, iron, and base metal ore deposits, may be created by fluid flow through and around interfaces in the Earth's crust. By understanding how, where and why such deposits form, we will assist exploration for future resources of these metals. Insights will also be gained into petroleum resource generation and extraction, the distribution of seismicity and volcanoes in time and spac ....Modeling fluid flow and mineralisation at crustal interfaces. Several types of mineral resources, including some uranium, iron, and base metal ore deposits, may be created by fluid flow through and around interfaces in the Earth's crust. By understanding how, where and why such deposits form, we will assist exploration for future resources of these metals. Insights will also be gained into petroleum resource generation and extraction, the distribution of seismicity and volcanoes in time and space, the problems of underground nuclear waste disposal and sequestration of CO2, and the potential for geothermal energy, with benefits in resource identification and/or hazard assessment in these areas.Read moreRead less