Relationship between subduction zone geometry, trench kinematics and great subduction earthquakes. The devastating Boxing Day 2004 earthquake near Sumatra and the four other largest earthquakes in recorded history all occurred along subduction zones. This research will compare the geodynamic setting of these subduction zones with those surrounding the Australian continent and assess whether the Australian subduction zones are capable of producing great earthquakes and tsunamis that might pose a ....Relationship between subduction zone geometry, trench kinematics and great subduction earthquakes. The devastating Boxing Day 2004 earthquake near Sumatra and the four other largest earthquakes in recorded history all occurred along subduction zones. This research will compare the geodynamic setting of these subduction zones with those surrounding the Australian continent and assess whether the Australian subduction zones are capable of producing great earthquakes and tsunamis that might pose a risk for the east and northwest coast of Australia. Also, Eastern Australia is a composite of fossil arcs rich in ore deposits and the Tasman Sea region is composed of basins that host hydrocarbons, all of which formed by subduction processes. The proposed research will thus improve the basis for mineral and hydrocarbon exploration.Read moreRead less
Integrated dynamic models of subduction initiation, slab evolution, arc - back-arc deformation and mantle convection. A major debate in plate tectonics concerns the driving mechanism for formation of extensional back-arc basins in the overriding plate along a convergent tectonic boundary, where a subducting plate is thrust into the mantle underneath an overriding plate. One hypothesis states that such extension results from sinking and rollback of the subducting plate. The physical validity of t ....Integrated dynamic models of subduction initiation, slab evolution, arc - back-arc deformation and mantle convection. A major debate in plate tectonics concerns the driving mechanism for formation of extensional back-arc basins in the overriding plate along a convergent tectonic boundary, where a subducting plate is thrust into the mantle underneath an overriding plate. One hypothesis states that such extension results from sinking and rollback of the subducting plate. The physical validity of this hypothesis will be tested using both laboratory and numerical modelling techniques. The modelling will investigate overriding plate - subducting plate - mantle interaction in three-dimensional space and quantify the role of key physical parameters on the subduction process.Read moreRead less
Solidification, Channel Formation and Thermal Erosion In Lava Flows. This project will elucidate the complex dynamics that control the cooling rates and advance rates of lava flows. It will result in improved hazard assessments for volcanic areas around the world affected by the advance of lava flows, including many Pacific islands and most countries around the Pacific Rim. The project will also provide a quantitative understanding of thermal erosion in lava channels, which will help explain th ....Solidification, Channel Formation and Thermal Erosion In Lava Flows. This project will elucidate the complex dynamics that control the cooling rates and advance rates of lava flows. It will result in improved hazard assessments for volcanic areas around the world affected by the advance of lava flows, including many Pacific islands and most countries around the Pacific Rim. The project will also provide a quantitative understanding of thermal erosion in lava channels, which will help explain the formation and location of major ore deposits of nickel, copper and platinum in Western Australia and elsewhere around the world.Read moreRead less
The Fluid Dynamics of Lava Flows: Silicic Domes and Basaltic Channels. Lava flows surface much of the Earth, Moon and terrestrial planets. This interdisciplinary program will combine laboratory experiments, mathematical analysis, numerical modelling and field observations to elucidate the complex dynamics of lava flows, including the nonlinear coupling of flow with surface solidification and basal melting. The focus will be on lava dome instability, and flow in open channels and tubes. Expected ....The Fluid Dynamics of Lava Flows: Silicic Domes and Basaltic Channels. Lava flows surface much of the Earth, Moon and terrestrial planets. This interdisciplinary program will combine laboratory experiments, mathematical analysis, numerical modelling and field observations to elucidate the complex dynamics of lava flows, including the nonlinear coupling of flow with surface solidification and basal melting. The focus will be on lava dome instability, and flow in open channels and tubes. Expected outcomes include: the ability to predict rates of lava flow cooling and advance, indicators of hazardous lava dome collapse, improved volcanic hazard assessments, explanations of the genesis of world-class magmatic ore deposits, and new interpretations of planetary surface morphologies.Read moreRead less
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
Chemical influences on the seismic structure of the Earth's upper mantle. This project aims to determine the sensitivity of the seismic properties of Earth’s upper mantle (to 400 km depth) to variations in the prevailing chemical environment. The unique capability of the ANU Rock Physics Laboratory for low-frequency measurement of wave speeds and attenuation will be exploited to clarify the newly discovered importance of redox conditions, and document the effect of varying proportions of the mos ....Chemical influences on the seismic structure of the Earth's upper mantle. This project aims to determine the sensitivity of the seismic properties of Earth’s upper mantle (to 400 km depth) to variations in the prevailing chemical environment. The unique capability of the ANU Rock Physics Laboratory for low-frequency measurement of wave speeds and attenuation will be exploited to clarify the newly discovered importance of redox conditions, and document the effect of varying proportions of the most abundant upper-mantle minerals olivine and pyroxene. The expected outcome will be a robust and comprehensive model to guide the interpretation of the complex architecture of the upper mantle, and thereby provide an improved understanding of the tectonic processes responsible for its evolution through geological time.Read moreRead less
Metamorphism, fluid flow, anatexis and the petrogenesis of peraluminous magmas: constraints from boron and lithium elemental and isotopic geochemistry. Boron (B) and lithium (Li) elemental and isotopic variations are sensitive monitors of metamorphism, fluid flow and melting; the generation of granites; and hydrothermal alteration. However, in detail B- and Li- geochemistry are poorly understood. This project uses field-based, analytical and experimental techniques to constrain B and Li elementa ....Metamorphism, fluid flow, anatexis and the petrogenesis of peraluminous magmas: constraints from boron and lithium elemental and isotopic geochemistry. Boron (B) and lithium (Li) elemental and isotopic variations are sensitive monitors of metamorphism, fluid flow and melting; the generation of granites; and hydrothermal alteration. However, in detail B- and Li- geochemistry are poorly understood. This project uses field-based, analytical and experimental techniques to constrain B and Li elemental and stable isotope variations in order to better understand high-temperature metamorphism, fluid flow, melting and the generation of granites and pegmatites. The results of this project will greatly increase our understanding of B and Li systematics in high-temperature crustal environments, and have implications for a range of metamorphic and igneous processes.Read moreRead less
How has the continental lithosphere evolved? Processes of assembly, growth, transformation and destruction. We will use new in-situ analytical techniques, developed In-house, to date the formation and modification of specific volumes of the subcontinental lithospheric mantle, and to define the temporal and genetic relationships between mantle events and crustal formation. Quantitative modelling will investigate the geodynamic consequences of spatial and temporal variations in lithosphere composi ....How has the continental lithosphere evolved? Processes of assembly, growth, transformation and destruction. We will use new in-situ analytical techniques, developed In-house, to date the formation and modification of specific volumes of the subcontinental lithospheric mantle, and to define the temporal and genetic relationships between mantle events and crustal formation. Quantitative modelling will investigate the geodynamic consequences of spatial and temporal variations in lithosphere composition and thermal state. Magmatic products will be used to assess the roles of mantle plumes and delamination in construction of the lithosphere and xenolith studies will investigate the evolution of oceanic plateaus. The results will provide a framework for interpreting the architecture of lithospheric terranes and their boundaries.Read moreRead less
How has continental lithosphere evolved? Processes of assembly, growth, transformation and destruction. Novel in-situ analytical and dating techniques will be used on samples from the Earth's mantle and deep crust to define the processes by which the continents and their roots (to depths of 250 km) have been formed, modified or destroyed at different times throughout Earth's 4.6 billion year evolution. The role of oceanic plateaus and mantle plumes in building protocontinents or modifying lithos ....How has continental lithosphere evolved? Processes of assembly, growth, transformation and destruction. Novel in-situ analytical and dating techniques will be used on samples from the Earth's mantle and deep crust to define the processes by which the continents and their roots (to depths of 250 km) have been formed, modified or destroyed at different times throughout Earth's 4.6 billion year evolution. The role of oceanic plateaus and mantle plumes in building protocontinents or modifying lithospheric volumes will be evaluated. The results will provide a more robust framework for interpreting the architecture of Earth's lithosphere and will have relevance to the formation and location of resources such as Ni, PGEs, Au and diamonds.Read moreRead less