The geochemistry of trace elements with variable oxidation states. The understanding of many earth processes is based upon an interpretation of differences in the relative abundance and/or distribution of elements which occur in more than one oxidation state. However, the redox states that control the geochemical behaviour of an element in a melt are not necessarily retained on cooling. This work aims to determine the oxidation states of geologically important elements, in situ under magmatic ....The geochemistry of trace elements with variable oxidation states. The understanding of many earth processes is based upon an interpretation of differences in the relative abundance and/or distribution of elements which occur in more than one oxidation state. However, the redox states that control the geochemical behaviour of an element in a melt are not necessarily retained on cooling. This work aims to determine the oxidation states of geologically important elements, in situ under magmatic conditions, using XANES spectroscopy. The results will allow geological signatures to be correctly interpreted and allow models for topics ranging from ancient mantle temperatures to rates of melt migration to be better constrained.Read moreRead less
The composition and transport of Australian air-borne dust: critical to continental and marine environments. This project will determine the composition of Australian airborne dust and effects on the environment and in particular soils, rainforests and the marine realm, including reefs. 'Fingerprinting' the chemical and microbiological content of aeolian dust is of particular relevance to determining its impact on the health of the Australian people and environment. Atmospheric conditions propit ....The composition and transport of Australian air-borne dust: critical to continental and marine environments. This project will determine the composition of Australian airborne dust and effects on the environment and in particular soils, rainforests and the marine realm, including reefs. 'Fingerprinting' the chemical and microbiological content of aeolian dust is of particular relevance to determining its impact on the health of the Australian people and environment. Atmospheric conditions propitious for dust entrainment and transport will be determined, and in particular atmospheric exchanges between Indonesia, southern Africa and Australia will be established. The relevance of aeolian dust to climate, ecosystems and biosecurity in our region will be established through the study of marine and lacustrine cores.Read moreRead less
The hydrothermal solubility of molybdenum: A LA-ICPMS study of synthetic and natural fluid inclusions. The solubility of molybdenum under magmatic-hydrothermal conditions is essentially unknown. This study will, for the first time, identify the fundamental controls on molybdenum solubility in porphyry systems. This information will provide geologists with basic information on the transport and deposition of this important ore metal. In an allied study, the ore metals; copper, gold and molybdenum ....The hydrothermal solubility of molybdenum: A LA-ICPMS study of synthetic and natural fluid inclusions. The solubility of molybdenum under magmatic-hydrothermal conditions is essentially unknown. This study will, for the first time, identify the fundamental controls on molybdenum solubility in porphyry systems. This information will provide geologists with basic information on the transport and deposition of this important ore metal. In an allied study, the ore metals; copper, gold and molybdenum, will be traced through the Kidston porphyry system, Queensland. This will clarify the processes that lead to ore deposition, which will ultimately allow geologists to more effectively explore for porphyry-type deposits, a major target for Australian mining companies in the Pacific region.Read moreRead less
Rich Cousin, Poor Cousin - What Controls the Formation and Size of Orogenic Gold Deposits? What are the geological and geochemical factors that control the formation and size of gold deposits in Phanerozoic mountain belts (?orogens?)? The answer to this question lies in a combination of methods we will use to establish the importance of source, absolute timing of mineralisation, genetic links to magmas, and geochemical processes that result in the transport, and deposition of gold in three separ ....Rich Cousin, Poor Cousin - What Controls the Formation and Size of Orogenic Gold Deposits? What are the geological and geochemical factors that control the formation and size of gold deposits in Phanerozoic mountain belts (?orogens?)? The answer to this question lies in a combination of methods we will use to establish the importance of source, absolute timing of mineralisation, genetic links to magmas, and geochemical processes that result in the transport, and deposition of gold in three separate, geologically young orogens. The wider implications of this research include a greatly improved understanding of lesser known Phanerozoic orogenic gold provinces, ore genesis at convergent plate margins, and the formation of gold deposits in older terrains.Read moreRead less
Magnetite and metal-rich sulphides in arc magmas. Ascending magmas cool and crystallise a variety of minerals. Triggering sulfide deposition which hosts base and precious metals is a critical point in magma evolution. This research will explore the role of magnetite as this trigger and its potential as a tracer of this process.
Aqueous fluids in the deep earth. This project aims to improve our understanding of the role of fluids in controlling exchanges between the deep Earth, shallow rocks, and atmosphere. The project expects to investigate some of the key weaknesses in the thermodynamic models that are used to predict the behaviour of sulphur, carbon and metals in fluids at high pressure and temperature by using recent advances in computational and experimental (geo)chemistry. Integrated in large-scale geodynamic mod ....Aqueous fluids in the deep earth. This project aims to improve our understanding of the role of fluids in controlling exchanges between the deep Earth, shallow rocks, and atmosphere. The project expects to investigate some of the key weaknesses in the thermodynamic models that are used to predict the behaviour of sulphur, carbon and metals in fluids at high pressure and temperature by using recent advances in computational and experimental (geo)chemistry. Integrated in large-scale geodynamic models, the more reliable predictions will provide a more realistic assessment of the role of sulphur in controlling metal endowment and atmospheric chemistry through geological times. This should provide a useful guide for mineral exploration and planetary science.Read moreRead less
Uncoupling past salinity and temperature signals in the Indo-Pacific Warm Pool: implications for climate change in the Australian region. The tropical oceans and in particular the Indo-Pacific Warm Pool, immediately to Australia's north, play a key role in modulating global and Australian climate through El-Niño and related phenomena. Using a new microanalysis approach to analyse individual foraminifera from deep-sea cores, we will reconstruct past salinity and temperature variability within the ....Uncoupling past salinity and temperature signals in the Indo-Pacific Warm Pool: implications for climate change in the Australian region. The tropical oceans and in particular the Indo-Pacific Warm Pool, immediately to Australia's north, play a key role in modulating global and Australian climate through El-Niño and related phenomena. Using a new microanalysis approach to analyse individual foraminifera from deep-sea cores, we will reconstruct past salinity and temperature variability within the Warm Pool, and determine changing rainfall patterns and, ENSO and monsoon behaviour under climate conditions that lie outside modern records. This information is vital for understanding past climate and predicting the future intensity and frequency of El-Niño related drought and wet cycles in Australia.Read moreRead less
The Geochemistry of the Platinum Group Elements, Copper, Rhenium and Gold in Granitic Rocks. Many of the World's largest copper and gold deposits derive their ore fluids from crystallizing granitic magmas. These elements, together with the platinum group elements, are sequestered by immiscible sulfide melts, which when they precipitate from a magma, control the subsequent evolution of these elements. The proposed study takes advantage of platinum's remarkable affinity for sulfides to identify ....The Geochemistry of the Platinum Group Elements, Copper, Rhenium and Gold in Granitic Rocks. Many of the World's largest copper and gold deposits derive their ore fluids from crystallizing granitic magmas. These elements, together with the platinum group elements, are sequestered by immiscible sulfide melts, which when they precipitate from a magma, control the subsequent evolution of these elements. The proposed study takes advantage of platinum's remarkable affinity for sulfides to identify onset of sulfide saturation and then monitor its effect on the subsequent evolution of copper and gold in the evolving magma. It is expected to provide new insights into chemistry of copper and gold in crystallizing granitic melts and explain why some granitic systems are ore bearing and other are not. Read moreRead less
Carbon and Hydrogen in Melts and Fluids in Planetary Interiors. The Australian community will benefit by the ownership of widely used high impact research in published earth science. This research defines the melting behaviour of silicate-rich materials (terrestrial planets, rocky-moons, meteorites) within the solar system. The research will be required for interpretation of Martian samples and will help to ensure that Australian laboratories participate in 21st Century investigations of the Sol ....Carbon and Hydrogen in Melts and Fluids in Planetary Interiors. The Australian community will benefit by the ownership of widely used high impact research in published earth science. This research defines the melting behaviour of silicate-rich materials (terrestrial planets, rocky-moons, meteorites) within the solar system. The research will be required for interpretation of Martian samples and will help to ensure that Australian laboratories participate in 21st Century investigations of the Solar System by virtue of their leading roles in understanding volcanism and melting behaviour at high pressures and under variable oxidation states. The research will address a national priority in sustainability of earth resources i.e. knowledge underpinning formation of Australian mineral resources.Read moreRead less
Experimental and natural constraints on trace element and volatile recycling in subduction zones. The results of this project will provide important constraints on the differentiation of Earth, which ultimately leads to the concentration of elements suitable for mining. Trace element and volatile recycling in subduction zones is an integral part of the research theme 'Journey to the centre of the Earth' which has been identified as a key project (4.4) in the national strategic plan for geoscienc ....Experimental and natural constraints on trace element and volatile recycling in subduction zones. The results of this project will provide important constraints on the differentiation of Earth, which ultimately leads to the concentration of elements suitable for mining. Trace element and volatile recycling in subduction zones is an integral part of the research theme 'Journey to the centre of the Earth' which has been identified as a key project (4.4) in the national strategic plan for geosciences. CO2 recycling in subduction zones is crucial for our understanding of the long-term greenhouse gas variations on Earth. The ANU is one of the world-leading research institutions in experimental petrology and geochemistry, and the outcomes of this project will ensure that Australia remains at the forefront in these disciplines.Read moreRead less