Marine Geological Investigation of the Naturaliste Plateau and Diamantina Zone - the tectono-magmatic development of a non-volcanic passive margin. Australia's continental margins impact enormously on our major industries including tourism, hydrocarbon production and fisheries, and are particularly significant with respect to biodiversity and hazard planning (both long and short term), yet knowledge of the seafloor of our margins is desperately poor. To contribute to alleviating this problem, we ....Marine Geological Investigation of the Naturaliste Plateau and Diamantina Zone - the tectono-magmatic development of a non-volcanic passive margin. Australia's continental margins impact enormously on our major industries including tourism, hydrocarbon production and fisheries, and are particularly significant with respect to biodiversity and hazard planning (both long and short term), yet knowledge of the seafloor of our margins is desperately poor. To contribute to alleviating this problem, we will use the R/V Southern Surveyor research vessel to produce swath mapping imagery and dredge samples from the seafloor of a geologically fascinating part of the southern section of the Western Australian margin dominated by the Naturaliste Plateau and Diamantina Zone. Read moreRead less
THE TIME SCALES OF MAGMATIC AND EROSIONAL CYCLES. Precise information on time scales and rates of change is fundamental to understanding natural processes and the development and testing of quantitative physical models in the Earth Sciences. Uranium decay-series isotope studies are revolutionising this field by providing time information in the range 100-100000 years, similar to that of many important Earth processes. This project will establish a dedicated Uranium-series research laboratory and ....THE TIME SCALES OF MAGMATIC AND EROSIONAL CYCLES. Precise information on time scales and rates of change is fundamental to understanding natural processes and the development and testing of quantitative physical models in the Earth Sciences. Uranium decay-series isotope studies are revolutionising this field by providing time information in the range 100-100000 years, similar to that of many important Earth processes. This project will establish a dedicated Uranium-series research laboratory and investigate (1) the processes and time scales of magma formation, transport and differentiation beneath western Pacific island arc volcanoes, (2) the time scales and relative roles of physical and chemical erosion in Australian river basins.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
Thallium isotopes: a novel geochemical tracer to map recycling in Earth's mantle. This project will transfer to Australia an advanced new methodology: the characterisation of thallium isotopic signatures in the mantle system introduced during recycling of crustal material. This will allow the tracking of fluid processes in the mantle system in a completely new way and will provide significant new information about the fluids that can percolate up from subduction zones. The source of most econo ....Thallium isotopes: a novel geochemical tracer to map recycling in Earth's mantle. This project will transfer to Australia an advanced new methodology: the characterisation of thallium isotopic signatures in the mantle system introduced during recycling of crustal material. This will allow the tracking of fluid processes in the mantle system in a completely new way and will provide significant new information about the fluids that can percolate up from subduction zones. The source of most economically interesting elements in the crust is from mantle-derived fluids, so their characterisation is critical to an understanding of the whole ore-forming process. Hence, this study will provide unique new information to apply to this important large-scale Earth problem.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
Australia's mammalian carnivore diversity in space and time. To more effectively address the current extinction crisis we need to understand past diversity. This research program will comprehensively investigate the diversity of mammalian carnivores on three continents over geological time. Results will provide insight into whether the evolution of Australia's mammal carnivores differs fundamentally from those of other continents, as has often been suggested but not quantitatively demonstrated. ....Australia's mammalian carnivore diversity in space and time. To more effectively address the current extinction crisis we need to understand past diversity. This research program will comprehensively investigate the diversity of mammalian carnivores on three continents over geological time. Results will provide insight into whether the evolution of Australia's mammal carnivores differs fundamentally from those of other continents, as has often been suggested but not quantitatively demonstrated. Studies focused in the present are important, but often miss critical factors that can only be clarified through analyses with deep time perspectives. The findings will translate into an improved understanding of what makes Australia unique and better-informed decisions regarding wildlife management.Read moreRead less
Mantle Melting Dynamics and the Influence of Recycled Components. This proposal is directly concerned with the continuing aim of building a sustainable Australia through knowledge of deep earth resources. The more we know about the processes of melting and melt and fluid migration the better we will be able to inform models for resource exploration and volcanic hazard mitigation. Uranium series isotopes are relevant to the very recent history of the planet (< 350 000 years) - time scales which a ....Mantle Melting Dynamics and the Influence of Recycled Components. This proposal is directly concerned with the continuing aim of building a sustainable Australia through knowledge of deep earth resources. The more we know about the processes of melting and melt and fluid migration the better we will be able to inform models for resource exploration and volcanic hazard mitigation. Uranium series isotopes are relevant to the very recent history of the planet (< 350 000 years) - time scales which are often overlooked. Application to mantle melting as described in this proposal may also have direct application to gold exploration in the Manus basin and elsewhere. It is to these techniques we must look if we are to understand the immediate past as a clue to the immediate future of our planet.Read moreRead less
The Initiation of Early Palaeozoic Subduction in Eastern Australia and North America: causes and effects. Identified thirty or more years ago subduction is the return of cold, dense, oceanic lithosphere to the mantle and is one of the key dynamic elements of the plate tectonic paradigm. It is this process that is responsible for the 'Pacific Ring of Fire'. It is the root cause of many key geological processes and is a primary control of some of the earth's largest-scale physiographic features, i ....The Initiation of Early Palaeozoic Subduction in Eastern Australia and North America: causes and effects. Identified thirty or more years ago subduction is the return of cold, dense, oceanic lithosphere to the mantle and is one of the key dynamic elements of the plate tectonic paradigm. It is this process that is responsible for the 'Pacific Ring of Fire'. It is the root cause of many key geological processes and is a primary control of some of the earth's largest-scale physiographic features, including deep-sea trenches and mountain ranges. Using the important record of Cambrian in eastern Australia and in the comparable Canadian Atlantic margin, we will look at the causes and impact of the earliest stages of subduction as it first developed in the western Pacific and pre-cursor Atlantic 500 million years ago.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