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
The copper-gold fertility of mountain belts. This project aims to identify the timing of, and understand the causes of, sulphide saturation in granitic suites to test the hypothesis that sulphide saturation controls the fertility of copper-gold deposits. More than half of the world’s copper and gold comes from granitic rocks, but most granitic suites are barren. As copper-gold deposits become increasingly difficult to find, and exploration budgets have been slashed, it is critical to reliably di ....The copper-gold fertility of mountain belts. This project aims to identify the timing of, and understand the causes of, sulphide saturation in granitic suites to test the hypothesis that sulphide saturation controls the fertility of copper-gold deposits. More than half of the world’s copper and gold comes from granitic rocks, but most granitic suites are barren. As copper-gold deposits become increasingly difficult to find, and exploration budgets have been slashed, it is critical to reliably distinguish ore bearing from barren systems. Platinum group element geochemistry could make this distinction by pinpointing the timing of sulphide saturation in evolving magma systems. Eliminating barren suites as exploration targets will save Australia’s exploration dollars which can be directed to where the prospects of success are greatest.Read moreRead less
Deep and smelly: exploring the roles of pressure and sulphur in hydrothermal metal transport. Hot, salty fluids carry metals in the Earth's crust and are responsible for the formation of Australia's mineral wealth. This project combines exciting new experiments with molecular-level simulations to predict metal transport, providing a sound basis for improving mineral exploration models and sustaining discovery of new deposits.
The origin of iron formations: implications for ancient ocean chemistry and the evolution of microbial life. Iron formations host most of the world's iron reserves and are central to our understanding of ancient ocean chemistry and the diversity of microbial life. Despite their scientific importance, questions remain about their original composition and formation. Preliminary work suggests that basic assumptions about their deposition require reevaluation. This project will use new technology an ....The origin of iron formations: implications for ancient ocean chemistry and the evolution of microbial life. Iron formations host most of the world's iron reserves and are central to our understanding of ancient ocean chemistry and the diversity of microbial life. Despite their scientific importance, questions remain about their original composition and formation. Preliminary work suggests that basic assumptions about their deposition require reevaluation. This project will use new technology and novel methods to investigate the precursor sediments of iron formations and their temporal relationship with periods of global magmatism and atmospheric oxygenation. Results will be used to test and develop new depositional models for iron formations, underpinning interpretations about the composition of the Precambrian ocean, atmosphere and biosphere. Read moreRead less
Gold transport in aqueous versus organic fluids: Experimental data for describing ore-forming systems. In many hydrothermal ore-forming systems, the ore is associated with inclusions of both aqueous brine and organic liquid (petroleum). The conventional theory is that the metals are dissolved and transported to the deposit by the brine, but some researchers suggest that petroleum may fill this role. This project proposes to conduct an experimental and field-based study on the chemical behaviour ....Gold transport in aqueous versus organic fluids: Experimental data for describing ore-forming systems. In many hydrothermal ore-forming systems, the ore is associated with inclusions of both aqueous brine and organic liquid (petroleum). The conventional theory is that the metals are dissolved and transported to the deposit by the brine, but some researchers suggest that petroleum may fill this role. This project proposes to conduct an experimental and field-based study on the chemical behaviour of gold in aqueous-organic and organic fluid systems, to determine which type of liquid is more important for gold mobilisation in a competitive situation. This study will provide much-needed data for more accurate modelling of ore systems, furthering our understanding and facilitating mineral exploration. Read moreRead less
The biogeochemical cycling of gold: development of innovative strategies in exploration. Doctor Southam's application of fundamental geomicrobiology to mineral exploration and mineral processing will enhance Australia's leadership in the global mining industry. The use of natural processes to develop biotechnological innovations will result in more sustainable mining practices.
Magnetite and metal-rich sulphides in arc magmas. Ascending magmas cool and crystallise a variety of minerals. Triggering sulfide deposition which hosts base and precious metals is a critical point in magma evolution. This research will explore the role of magnetite as this trigger and its potential as a tracer of this process.
Resolving the influence of intraplate orogenesis on continental margin tectonics. Novel, multi-dating of continental sedimentary rocks will be undertaken to examine the effects of a high sediment flux from an enigmatic, major mountain-building event on a distant continental margin. This will expand our understanding of the range of tectonic influences between continental interiors and margins and onshore resource potential.
Multiple vertical tectonic movements in a continental interior: consequences of flat-subduction and foundering of an oceanic plateau? This project will investigate how the subduction of particularly thick oceanic crust impacts on the landscape, climate, structure and composition of the adjacent continent. It will help in understanding the history and distribution of mineral and hydrocarbon resources, of similar provinces in Australia.
Continents in the Mantle Transition Zone? Sediment Recycling and the Geochemical Fertilization of the Deep Mantle. Because of its intrinsic compositional buoyancy, continental crust has traditionally been considered to be unsubductable in the denser underlying mantle. Yet some ocean island basalts carry a geochemical signature of recycled continental material in their plume source in the deep mantle. This project will reconcile this paradox through high-pressure experiments that will simulate su ....Continents in the Mantle Transition Zone? Sediment Recycling and the Geochemical Fertilization of the Deep Mantle. Because of its intrinsic compositional buoyancy, continental crust has traditionally been considered to be unsubductable in the denser underlying mantle. Yet some ocean island basalts carry a geochemical signature of recycled continental material in their plume source in the deep mantle. This project will reconcile this paradox through high-pressure experiments that will simulate subduction of continental sediments into the deep mantle. These experiments will provide the first empirical constraints on the role of sediment-derived fluids in mantle metasomatism and the origin of economically-rich potassic magmas, and the nature of the ultrarefractory continental component that ultimately reaches the plume source for ocean-island basalts.Read moreRead less