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 structure and geochemistry of mineral interfaces in Earth's mantle. The interfaces between mineral grains are critical in determining rock properties and behaviour, yet we know little about them. This project uses emerging nano-technologies to establish the structure, chemistry and energy characteristics of interfaces in rocks from Earth’s mantle that control fundamental Earth processes such as plate tectonics and melting. The expected outcomes include a new understanding on one of the funda ....The structure and geochemistry of mineral interfaces in Earth's mantle. The interfaces between mineral grains are critical in determining rock properties and behaviour, yet we know little about them. This project uses emerging nano-technologies to establish the structure, chemistry and energy characteristics of interfaces in rocks from Earth’s mantle that control fundamental Earth processes such as plate tectonics and melting. The expected outcomes include a new understanding on one of the fundamental controls on rock properties and an enhanced ability to predict and model rock behaviour. The project provides research training in innovative research methodologies, will strengthen Australia’s leadership in nano-geoscience and will provide new methodologies for advanced rock characterisation.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
Defects and Deformation in Olivine: From Molecules to Mantle. This project establishes the role of hydrogen in controlling olivine deformation, plate tectonics and mantle geodynamics. The unique application of innovative nanoscale simulation, microscale observation and geophysical characterisation ensures that results will have far-reaching impact in the Australian and International Earth Science community. In particular, our results will enable greater understanding of water migration in the m ....Defects and Deformation in Olivine: From Molecules to Mantle. This project establishes the role of hydrogen in controlling olivine deformation, plate tectonics and mantle geodynamics. The unique application of innovative nanoscale simulation, microscale observation and geophysical characterisation ensures that results will have far-reaching impact in the Australian and International Earth Science community. In particular, our results will enable greater understanding of water migration in the mantle, the formation of deep Earth mineral resources and lead to significant improvements in the interpretation of geophysical variations in Earth's lithosphere.Read moreRead less
The Earth's Deep Carbon Cycle. The climate change debate has focused scientific attention on Earth’s exogene carbon-cycle. However, Earth has another, much deeper carbon-cycle which is poorly understood. In addition to exerting a profound influence on atmospheric greenhouse gas concentrations over time scales from thousands to billions of years, it is critically important in many processes in the Earth’s deep mantle. The major means by which the deep carbon-cycle is replenished is via subduction ....The Earth's Deep Carbon Cycle. The climate change debate has focused scientific attention on Earth’s exogene carbon-cycle. However, Earth has another, much deeper carbon-cycle which is poorly understood. In addition to exerting a profound influence on atmospheric greenhouse gas concentrations over time scales from thousands to billions of years, it is critically important in many processes in the Earth’s deep mantle. The major means by which the deep carbon-cycle is replenished is via subduction of carbonate-bearing oceanic crust. The project proposes a high-pressure experimental and field-based program to understand the fate of this carbonate during its journey from the exosphere, through subduction zones and into the deep mantle.Read moreRead less
The seismic significance of water and partial melting in planetary interiors. Novel laboratory techniques will be used to measure the influence of dissolved water on the seismic properties of the deep interiors of Earth and Moon. The outcome will be new insight into the crucial role of water in the formation and subsequent evolution of our dynamic planet and its more quiescent moon.
A Direct Approach to Crystal Structure Determination - a solution to the phase problem. The purpose of this research is to determine the positions of atoms in crystals and nano-crystals. We have developed a theory that shows how to extract all of the information required to determine atomic positions from such crystals and we have carried through initial successful tests on simple materials. In particular, we have found that crystallographic phase, hitherto not directly measurable, can in fact b ....A Direct Approach to Crystal Structure Determination - a solution to the phase problem. The purpose of this research is to determine the positions of atoms in crystals and nano-crystals. We have developed a theory that shows how to extract all of the information required to determine atomic positions from such crystals and we have carried through initial successful tests on simple materials. In particular, we have found that crystallographic phase, hitherto not directly measurable, can in fact be extracted uniquely from a single electron diffraction pattern. This constitutes a solution to the phase problem in crystallography. It is now our aim to develop this method into a routine technique.Read moreRead less
The Effects of Crystal-Plastic Deformation on Zircon Geochemical Systems. This project establishes the significance of deformation-related fast-diffusion pathways on the zircon geochemical system and develops intragrain compositional variations as new tools for tracking geological processes. The unique application of zircon to constrain geological processes in numerous Earth Science disciplines over 4.4 billion years of Earth history ensures that results will have far-reaching impact in the Aust ....The Effects of Crystal-Plastic Deformation on Zircon Geochemical Systems. This project establishes the significance of deformation-related fast-diffusion pathways on the zircon geochemical system and develops intragrain compositional variations as new tools for tracking geological processes. The unique application of zircon to constrain geological processes in numerous Earth Science disciplines over 4.4 billion years of Earth history ensures that results will have far-reaching impact in the Australian and International Earth Science community. As such this project will maintain Australia's leading international reputation in accessory mineral research.Read moreRead less