The geochemical role of iron in basaltic magmatism and planetary differentiation: an experimental study. The amount of Fe in primitive terrestrial basalts is surprisingly variable. The reasons for this are poorly understood, but could include melting of Fe-enriched refertilized mantle sources, increasing partitioning of FeO into the melt with depth of melting, or oxidation of some FeO to Fe2O3. An experimental investigation of the effects of Fe both as 2+ and 3+ on the partial melting of model ....The geochemical role of iron in basaltic magmatism and planetary differentiation: an experimental study. The amount of Fe in primitive terrestrial basalts is surprisingly variable. The reasons for this are poorly understood, but could include melting of Fe-enriched refertilized mantle sources, increasing partitioning of FeO into the melt with depth of melting, or oxidation of some FeO to Fe2O3. An experimental investigation of the effects of Fe both as 2+ and 3+ on the partial melting of model mantle material should help resolve this problem, while also providing the fundamental thermodynamic data needed to calibrate a general model for upper mantle phase relations.Read moreRead less
Understanding the deep mantle: experimental petrology at very high pressures. The great processes that shape the Earth at its surface, including plate tectonics and continental drift, can only be understood by appreciating how the interior of the Earth works. However, studying the deep Earth is difficult because of the enormous pressures and temperatures involved. This research proposes to simulate conditions in the Earth's lower mantle (that is, below 670 km in depth) by making use of an Austra ....Understanding the deep mantle: experimental petrology at very high pressures. The great processes that shape the Earth at its surface, including plate tectonics and continental drift, can only be understood by appreciating how the interior of the Earth works. However, studying the deep Earth is difficult because of the enormous pressures and temperatures involved. This research proposes to simulate conditions in the Earth's lower mantle (that is, below 670 km in depth) by making use of an Australian invented diamond-based ceramic, to double the pressure at which experiments can be performed. The information gained from this fundamental research will help predict how giant ore bodies form. The development of the high-pressure apparatus will also aid material scientists in their quest for novel materials.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
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
Experimental constraints on Platinum-Group Element geochemistry: developing lithogeochemical exploration tools for nickel-sulfides in mafic and ultramafic systems. Nickel contributes approximately $2 billion per year to Australia's export income. Currently 80% of that is coming from sulfide deposits, which are expected to be exhausted within thirty years barring significant new discoveries. Discovery rates have been declining for two decades, as the 'easy' targets have been found, despite a broa ....Experimental constraints on Platinum-Group Element geochemistry: developing lithogeochemical exploration tools for nickel-sulfides in mafic and ultramafic systems. Nickel contributes approximately $2 billion per year to Australia's export income. Currently 80% of that is coming from sulfide deposits, which are expected to be exhausted within thirty years barring significant new discoveries. Discovery rates have been declining for two decades, as the 'easy' targets have been found, despite a broad increase in nickel exploration expenditure to current levels of around $50 million per year. There is a pressing need for new data sets and techniques to allow industry to target new discoveries based on limited drill sampling of potential host rocks. This project forms part of a broader program to harness the igneous geochemistry of the platinum group elements as a powerful pathfinder in nickel exploration.Read moreRead less
Redox conditions in the earth's upper mantle and the implications for kimberlite petrogenesis, diamond formation and mantle metasomatism. Diamonds are an important and high value commodity. Australia is the world's leading producer in terms of carats, due mainly to the massive Argyle deposit in northern Western Australia. Although diamonds form at great depths in the earth, they are accessible at the surface because they are transported by rare volcanic rocks, kimberlites and lamproites. Despite ....Redox conditions in the earth's upper mantle and the implications for kimberlite petrogenesis, diamond formation and mantle metasomatism. Diamonds are an important and high value commodity. Australia is the world's leading producer in terms of carats, due mainly to the massive Argyle deposit in northern Western Australia. Although diamonds form at great depths in the earth, they are accessible at the surface because they are transported by rare volcanic rocks, kimberlites and lamproites. Despite their importance the genesis of these rocks is poorly understood. This research will address this, providing scientific constraints on models for formation of diamonds and their host volcanics, which will directly inform the minerals industry's exploration models. There will be an economic benefit to the nation in terms of more successful outcomes from exploration expenditure.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
Kimberlites and Flood Basalts: Linking Primary Melts with Mantle and Crustal Sources. Intimate relationships between kimberlites and diamonds, and between flood basalts and sulphide mineralisation make the study of deep mantle-derived magmas important to the scientific and exploration communities. The proposed research therefore represents a logical scientific step forward and is hence timely and important in this internationally competitive field, and serve as a training base for young research ....Kimberlites and Flood Basalts: Linking Primary Melts with Mantle and Crustal Sources. Intimate relationships between kimberlites and diamonds, and between flood basalts and sulphide mineralisation make the study of deep mantle-derived magmas important to the scientific and exploration communities. The proposed research therefore represents a logical scientific step forward and is hence timely and important in this internationally competitive field, and serve as a training base for young researchers keen to learn the techniques and methodologies involved. The possible outcomes of the project are of wide interest to geoscientists, and may benefit the Australian economy in that they help to predict whether the continental magmas and respective rocks have formed in parts of deep mantle with mineralisation potential.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