Antarctic marine diatoms: Key to predicting the effects of global climate change on a temperature-sensitive ecosystem. This project aims to determine the effects of global climate change on Antarctic diatoms. Diatoms are a major component of the polar phytoplankton. They are sensitive to changes in their marine environment, detection of which is an essential part of the Antarctic climate change strategy. Understanding the environmental processes that cause natural variation in extant diatoms ....Antarctic marine diatoms: Key to predicting the effects of global climate change on a temperature-sensitive ecosystem. This project aims to determine the effects of global climate change on Antarctic diatoms. Diatoms are a major component of the polar phytoplankton. They are sensitive to changes in their marine environment, detection of which is an essential part of the Antarctic climate change strategy. Understanding the environmental processes that cause natural variation in extant diatoms will make it possible to reconstruct the response of fossil diatoms, preserved in marine sediments, to past climate change. This understanding is vital for predicting the effect of future anthropogenic warming on this ecosystem.Read moreRead less
Volcanology of voluminous felsic lavas. Eruptions of voluminous lavas (>100km3)have occurred throughout geological time but not in recorded human history. These lavas are a major part of very large volcanic areas that form the continents. Excellent examples have been identified in the Gawler Range Volcanics, South Australia. Little is known about the eruption mechanisms and yet these events are the key to understanding large-scale melting processes deep in the Earth and continent formation. This ....Volcanology of voluminous felsic lavas. Eruptions of voluminous lavas (>100km3)have occurred throughout geological time but not in recorded human history. These lavas are a major part of very large volcanic areas that form the continents. Excellent examples have been identified in the Gawler Range Volcanics, South Australia. Little is known about the eruption mechanisms and yet these events are the key to understanding large-scale melting processes deep in the Earth and continent formation. This research will use field data from one of the South Australian examples to constrain the nature and position of the source volcanic centre and to clarify outflow mechanisms.Read moreRead less
Tectonic paradox of the E margin of the Australian plate, 120 - 45 Ma. Available geological evidence indicates that massive extension of continental crust occurred from 120-45 million years ago at the eastern margin of the Australian plate. In contrast, global plate movement models indicate that there was convergence between the Pacific and Australian plates, implying subduction and island arc magmatism. We propose a marine research expedition to dredge rocks from scarps of the submarine ridges ....Tectonic paradox of the E margin of the Australian plate, 120 - 45 Ma. Available geological evidence indicates that massive extension of continental crust occurred from 120-45 million years ago at the eastern margin of the Australian plate. In contrast, global plate movement models indicate that there was convergence between the Pacific and Australian plates, implying subduction and island arc magmatism. We propose a marine research expedition to dredge rocks from scarps of the submarine ridges east of Australia. Geochemical signatures and dating of the dredged rocks should elucidate the geological evolution of this region, improve our understanding of eastern Australian geology, and better define Australia's Maritime Jurisdiction Zone along the eastern seaboard.Read moreRead less
A detrital apatite archive to track crustal growth. This project will establish apatite as a new tool to study the evolution of the continental crust. The crust shaped the composition of the atmosphere and the oceans with consequences for the evolution of life through the availability of oxygen and nutrients. However, when and how the continental crust was generated remains a core question. Current models for continental crust development rely on the mineral zircon. However, zircons only record ....A detrital apatite archive to track crustal growth. This project will establish apatite as a new tool to study the evolution of the continental crust. The crust shaped the composition of the atmosphere and the oceans with consequences for the evolution of life through the availability of oxygen and nutrients. However, when and how the continental crust was generated remains a core question. Current models for continental crust development rely on the mineral zircon. However, zircons only record the history of evolved rocks. To address this bias we will use the mineral apatite which forms in less evolved rocks. We will develop a detrital apatite database of Pb-Nd (model) ages and integrate this with the zircon record to provide a more holistic description for how our planet developed.Read moreRead less
Unmixing in Magmas: Melt and Fluid Inclusion Constraints on Identity, Timing, and Evolution of Immiscible Fluids, Salt and Sulphide Melts. Much of the research proposed herein genuinely breaks new ground in both the fields of igneous petrology and ore deposit geology. It will contribute to Australia maintaining a leading role (as identified in "Towards 2005 - a prospectus for research and training in the Australian Earth sciences") in the burgeoning field of melt inclusion research, and serve as ....Unmixing in Magmas: Melt and Fluid Inclusion Constraints on Identity, Timing, and Evolution of Immiscible Fluids, Salt and Sulphide Melts. Much of the research proposed herein genuinely breaks new ground in both the fields of igneous petrology and ore deposit geology. It will contribute to Australia maintaining a leading role (as identified in "Towards 2005 - a prospectus for research and training in the Australian Earth sciences") in the burgeoning field of melt inclusion research, 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 magmas have experienced exsolution of a metal-rich fluid.Read moreRead less
PAST EAST ANTARCTIC ICE SHEET AND GLOBAL SEA-LEVEL VARIATIONS. Unique fossil-bearing, open marine sediments occur inland from the modern Antarctic coastline. These were deposited when a now-glaciated Antarctic basin became a marine embayment, during intervals of significantly reduced ice sheet volume and elevated global sea-level in the past. Urgent palaeontological, sedimentological and geochemical research on these sediments are vital to provide: directly datable in situ evidence for major i ....PAST EAST ANTARCTIC ICE SHEET AND GLOBAL SEA-LEVEL VARIATIONS. Unique fossil-bearing, open marine sediments occur inland from the modern Antarctic coastline. These were deposited when a now-glaciated Antarctic basin became a marine embayment, during intervals of significantly reduced ice sheet volume and elevated global sea-level in the past. Urgent palaeontological, sedimentological and geochemical research on these sediments are vital to provide: directly datable in situ evidence for major ice sheet retreat and global sea-level rise in the past; and quantifiable data concerning the environment during such events; an innovative opportunity to improve predictions of Antarctica's response to global warming and answer international debate about past Antarctic Ice Sheet stability.Read moreRead less
How the complexity of continental breakup controls ocean circulation. This project aims to address the evolution of oceanic seaways formed during separation of tectonic plates (such as Australia and Antarctica). The seaways that form are key components modulating the global ocean circulation system and are implicated in major glacial expansion events. This project aims to unravel their role relative to other drivers for example carbon dioxide (CO2). Unravelling the influence of seaway opening co ....How the complexity of continental breakup controls ocean circulation. This project aims to address the evolution of oceanic seaways formed during separation of tectonic plates (such as Australia and Antarctica). The seaways that form are key components modulating the global ocean circulation system and are implicated in major glacial expansion events. This project aims to unravel their role relative to other drivers for example carbon dioxide (CO2). Unravelling the influence of seaway opening compared with declining CO2 in the onset of Antarctic and Northern hemisphere glaciation will enable more accurate future climate simulations. The project will also give international exposure and training to the next generation of numerically adept geoscientists and oceanographers.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
Pyrite: a deep-time capsule of ocean chemistry and atmosphere oxidation. Surprisingly little is known about trace element trends in past oceans, even though these data are vital for interpreting the evolution of the Earth's atmosphere, evolutionary pathways of marine life and cycles of major mineral deposits. Using laser-based analysis of sedimentary pyrite in deep marine rocks, this project aims to produce, for the first time, temporal variation curves for 25 trace elements in seawater over the ....Pyrite: a deep-time capsule of ocean chemistry and atmosphere oxidation. Surprisingly little is known about trace element trends in past oceans, even though these data are vital for interpreting the evolution of the Earth's atmosphere, evolutionary pathways of marine life and cycles of major mineral deposits. Using laser-based analysis of sedimentary pyrite in deep marine rocks, this project aims to produce, for the first time, temporal variation curves for 25 trace elements in seawater over the last 3.5 billion years. Preliminary research has validated the technique and demonstrated major changes in certain trace elements over geologically short periods. Outcomes will assist the minerals industry in the discovery of new deposits of zinc, copper, gold and iron ore in Australia.Read moreRead less
Submarine explosive eruptions of silicic magma: constraints on products and processes from modern sea-floor examples, ancient successions and experiments. Volcanoes are common on the sea-floor. Many have been the sites of devastating explosive eruptions throughout Earth history, producing thick layers of pumice and volcanic ash in both modern and ancient ocean basins. None of these events has been witnessed, hence, little is known about submarine explosive eruptions and the associated volcanoes. ....Submarine explosive eruptions of silicic magma: constraints on products and processes from modern sea-floor examples, ancient successions and experiments. Volcanoes are common on the sea-floor. Many have been the sites of devastating explosive eruptions throughout Earth history, producing thick layers of pumice and volcanic ash in both modern and ancient ocean basins. None of these events has been witnessed, hence, little is known about submarine explosive eruptions and the associated volcanoes. This detailed, multidisciplinary study will link exploration of modern explosive sea-floor volcanoes (western Pacific Ocean), field-work on older, submarine volcanic formations (Japan, Greece) and experiments that simulate explosive eruptions and their products. The results will elucidate sea-floor explosive volcanism and its contribution to the geology of ocean basins.Read moreRead less