Surface-ground water interactions and increasing salinity in the upper Hunter River. Australia's first salinity trading scheme, to limit impacts of industrial saline wastewater discharges, operates in the Hunter Region, NSW. Despite it, a recent audit suggests stream salinity levels will continue to rise over the next century. No assessment tools are available to identify causes of salinity increases in sub-catchments of the Hunter. This severely limits rehabilitation strategies aimed at address ....Surface-ground water interactions and increasing salinity in the upper Hunter River. Australia's first salinity trading scheme, to limit impacts of industrial saline wastewater discharges, operates in the Hunter Region, NSW. Despite it, a recent audit suggests stream salinity levels will continue to rise over the next century. No assessment tools are available to identify causes of salinity increases in sub-catchments of the Hunter. This severely limits rehabilitation strategies aimed at addressing river salinity. Current rehabilitation focuses on revegetation of recharge and discharge areas, with limited understanding of the primary local drivers for salinity, and without assessment of whether rehabilitation is addressing or exacerbating problems. This project aims to supply that understanding.Read moreRead less
Sulfide Partial Melting at Broken Hill: Process and Implications. Based entirely on experimental studies, we suggested that the sulfide ore at Broken Hill, N.S.W., partially melted during granulite-facies metamorphism. Our subsequent discovery of sulfide melt inclusions in silicates associated with the ore strongly supports this assertion. This proposed research will evaluate the extent of melting and the composition of such a melt as well as the effect of this melt on the rocks surrounding the ....Sulfide Partial Melting at Broken Hill: Process and Implications. Based entirely on experimental studies, we suggested that the sulfide ore at Broken Hill, N.S.W., partially melted during granulite-facies metamorphism. Our subsequent discovery of sulfide melt inclusions in silicates associated with the ore strongly supports this assertion. This proposed research will evaluate the extent of melting and the composition of such a melt as well as the effect of this melt on the rocks surrounding the ore. The results of this basic research will not only impact on Broken Hill genetic models specifically, but could profoundly effect our understanding of metamorphic and magmatic sulfide deposits globally.Read moreRead less
The Southern Ocean's role in determining atmospheric CO2 levels: new insights from novel biogenic silica records of seawater pH. About half the emissions from the burning of fossil fuel since the Industrial Revolution have been absorbed by the oceans. However, considerable uncertainty surrounds the consequences of and the extent to which the oceans will continue to sequester CO2 into the future. This research will improve existing limited knowledge of the key biological and related ocean process ....The Southern Ocean's role in determining atmospheric CO2 levels: new insights from novel biogenic silica records of seawater pH. About half the emissions from the burning of fossil fuel since the Industrial Revolution have been absorbed by the oceans. However, considerable uncertainty surrounds the consequences of and the extent to which the oceans will continue to sequester CO2 into the future. This research will improve existing limited knowledge of the key biological and related ocean processes that transfer CO2 between the surface and depth, and the poorly understood effects on marine ecosystems of increasing ocean acidity due to CO2 absorption. This knowledge will contribute to predicting the course of future climate change and gauging the impacts on marine life and production systems.Read moreRead less
THE CORAL RECORD OF ENVIRONMENTAL IMPACTS IN THE GREAT BARRIER REEF:QUANTIFICATION OF ANTHROPOGENIC FLUXES. The objective of this proposal is to quantify the environmental impacts of enhanced terrestrial fluxes and climate change on the coral reefs in the Great Barrier Reef. This will be achieved by using an integrated approach based on coral proxy records of river plumes and sea surface temperatures that are preserved in carbonate skeletons of the long-lived (200-400 year old) Porites coral. ....THE CORAL RECORD OF ENVIRONMENTAL IMPACTS IN THE GREAT BARRIER REEF:QUANTIFICATION OF ANTHROPOGENIC FLUXES. The objective of this proposal is to quantify the environmental impacts of enhanced terrestrial fluxes and climate change on the coral reefs in the Great Barrier Reef. This will be achieved by using an integrated approach based on coral proxy records of river plumes and sea surface temperatures that are preserved in carbonate skeletons of the long-lived (200-400 year old) Porites coral. This will be integrated with monitoring and process studies of river flood plumes and coral reefs and provide a scientific basis to ensure the long-term sustainability of the GBR.Read moreRead less
Dynamics and Chemical Evolution of the Earth's Early Mantle. Preliminary numerical results demonstrate that the Earth's mantle may have been compositionally stratified early in its history through a novel interaction between compositional buoyancies and viscosity stratification. This result has important implications for the evolution of the crust and for the chemical and isotopic evolution of the mantle. It also complements recent geochemical evidence for the extraction of a basaltic componen ....Dynamics and Chemical Evolution of the Earth's Early Mantle. Preliminary numerical results demonstrate that the Earth's mantle may have been compositionally stratified early in its history through a novel interaction between compositional buoyancies and viscosity stratification. This result has important implications for the evolution of the crust and for the chemical and isotopic evolution of the mantle. It also complements recent geochemical evidence for the extraction of a basaltic component from the early upper mantle. It is proposed to explore the robustness of this phenomenon in two and three dimensions, its longer-term behaviour, and the evolution of the stratification as the mantle cools to its present condition.Read moreRead less
Early Evolution of the Solar System: A Planetary Perspective. A geochemical study of early solar system materials will be conducted to investigate physical conditions leading to assembly of the terrestrial planets, and the chronology of early geological events that shaped the Earth and Moon. Objects from the solar nebula and samples from the Earth, Moon, Mars, and differentiated asteroids will be studied. This research will contribute toward understanding the astrophysical environment of the inn ....Early Evolution of the Solar System: A Planetary Perspective. A geochemical study of early solar system materials will be conducted to investigate physical conditions leading to assembly of the terrestrial planets, and the chronology of early geological events that shaped the Earth and Moon. Objects from the solar nebula and samples from the Earth, Moon, Mars, and differentiated asteroids will be studied. This research will contribute toward understanding the astrophysical environment of the inner solar system, establish a high-resolution absolute timescale for early geological events, and Identify the population of solid bodies present during the initial stages of planetary development.Read moreRead less
Lithic Astronomy: The age and origin of the elements and their incorporation in the solar nebula. All heavy elements are produced in stars. The signature of nucleosynthesis is the isotopic composition of the elements and thus measurement of isotopic compositions allows nuclear astrophysics to be elucidated in the laboratory. This project will examine the linkages between stellar sites and the material in our solar system through measurement of interstellar grains and other primitive material ob ....Lithic Astronomy: The age and origin of the elements and their incorporation in the solar nebula. All heavy elements are produced in stars. The signature of nucleosynthesis is the isotopic composition of the elements and thus measurement of isotopic compositions allows nuclear astrophysics to be elucidated in the laboratory. This project will examine the linkages between stellar sites and the material in our solar system through measurement of interstellar grains and other primitive material obtained from meteorites. A chronology of processes affecting the solar nebula will be determined through measurement of radionuclides. Th/U measurements in presolar grains could allow a view of galactic chemical evolution billions of years prior to the solar nebula.Read moreRead less
Rates of metamorphic processes - correlating U-Pb ages with the pressure-temperature conditions of mineral growth. To determine the speed of metamorphic processes, the age obtained from accessory uranium-bearing minerals will be correlated to pressure and temperature obtained from major rock forming minerals. I will develop a new and innovative technique that uses trace element geochemistry to provide this link. The trace element partitioning between datable minerals (zircon, monazite and titani ....Rates of metamorphic processes - correlating U-Pb ages with the pressure-temperature conditions of mineral growth. To determine the speed of metamorphic processes, the age obtained from accessory uranium-bearing minerals will be correlated to pressure and temperature obtained from major rock forming minerals. I will develop a new and innovative technique that uses trace element geochemistry to provide this link. The trace element partitioning between datable minerals (zircon, monazite and titanite) and key metamorphic minerals will be investigated in natural samples and in piston cylinder experiments. I will apply this technique to the study of processes such as the exhumation of eclogites in subduction zones and the duration of granulite-facies metamorphism in lower crustal rocks.Read moreRead less