ARC Centre of Excellence for Core to Crust Fluid SystemsAppendix 2: Independently funded basic research projects
Independently funded research projects within CCFS contribute to the long-term, large-scale strategic goals and play an important role in determining the shorter-term research plans. Research goals for each year are thus linked to the aims of funded projects. Summaries of the current independently funded CCFS-related projects are given below.
Multiple vertical tectonic movements in a continental interior: consequences of flat-subduction and foundering of an oceanic plateau?
Z.X. Li, M. Danisik, Y. Xu: Supported by ARC Discovery
Summary: 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.
That lies beneath: Unveiling the fine-scale 3D compositional and thermal structure of the subcontinental lithosphere and upper mantle
J.C. Afonso, Y. Yang, N. Rawlinson, A.G. Jones, J.A.D. Connolly, S. Lebedev: Supported by ARC Discovery (commencing 2012)
Summary: Characterising the compositional and thermal structure of the lithosphere and upper mantle is one of the most important goals of Geoscience. Yet, a method capable of providing robust estimates of these two fields in 3D has still not been achieved. This limitation is the focus of this project, which will develop the first full 3D method that integrates multiple geophysical and petrological datasets. We will apply our methodology to image the fine-scale thermochemical structure of the lithosphere beneath Australia, South Africa, and western USA. This project will not only help us understand the evolution of continental lithosphere but its outcomes will be translatable into predictive exploration methods for Australia’s Deep Earth Resources.
The application of very short-lived Uranium-series isotopes to constraining Earth system processes
S. Turner, T. Dosseto, M. Reagan: Supported by ARC Discovery (commenced 2009)
Summary: Precise information on time scales is fundamental to understanding natural processes. Uranium series isotopes have revolutionised the way we think about time scales because they can date processes which occurred in the last 10-350 000 years. This proposal will establish new procedures at the recently founded world-class Uranium-series research facility at Macquarie University for analysing very short-lived isotopes (22 years). These new abilities will be utilised to determine the mechanisms of melt/fluid migration and volcano degassing and to ascertain rates of soil production and erosion over time. The methodologies developed will also have application to Uranium exploration and nuclear safeguarding.
The effective strength of oceanic plate bounding faults
C. O’Neill, J.-C. Afonso: Supported by ARC Discovery and MQ (commenced 2011)
Summary: The strength of the ocean faults surrounding the Australian plate controls the long-term fault motions, stress partitioning across the plate boundary and, ultimately, the seismicity of such fault systems. Numerous lines of evidence suggest such faults are far weaker than previous models predict, possibly due to the alteration of crustal and lithospheric rocks into hydrous phases. This is a critical gap in our understanding of such fault systems, and this project will ultimately constrain the weakening mechanisms acting on such faults, and produce a geodynamic-scale model for their effective strength. This project addresses the anomalously weak behaviour of the seismically active faults on the boundary of the Australian plate, in three key geodynamic areas. This will constrain the mechanisms which weaken such faults, and produce a model for their effective strength and evolution over geological timescales.
Origin of silicic magmas in a primitive island arc: the first integrated experimental and short-lived-isotope study of the Tongan Kermadec system
T. Rushmer, S. Turner: Supported by ARC Discovery (commenced 2011)
Summary: Silicic magmas are the building blocks of the continental crust and constitute the most hazardous of volcanic eruptions. Silica-rich magmas are found in the Tonga-Kermadec arc, which extends for several thousand km north of New Zealand. Application of a novel combination of experiments and short-lived isotopes to selected magma samples from the primitive Tonga arc will explain the origin of these magmas. The combined technique will also allow us to estimate water content, rates of melting and magma migration at depth, which are critical factors for understanding volcanic hazards. This approach can then be expanded to other parental magma types here and to other arc systems. The Tongan arc forms a large portion of the Australian plate boundary and is one of the most chemically primitive systems known. Oddly, it produces volumes of more evolved, dangerous silicic magmas. The results of this project will establish the source of these magmas and rates of migration, which are fundamental for understanding volcanic hazards.
Partial melting in natural metal-silicate and silicate systems: rheological and geochemical implications for the Earth and other planets
T. Rushmer: Supported by ARC Discovery (commenced 2009)
Summary: Differentiation is the separation of a melt or fluid from its host. It is the fundamental mechanism by which the terrestrial planets have evolved both chemically and physically through time and central to how the crust has evolved from mantle, how metallic cores are formed from undifferentiated planetary bodies and how economic elements can be concentrated. This proposal tackles this primary process by using the true (observed) rock textures and compositions as templates uniquely constrained by experiment so that numerical modelling can quantify flow processes and deformation regimes. It provides a basis for understanding fluid migration in dynamically evolving permeable networks.
Oxygenating the Earth: using innovative techniques to resolve the timing of the origin of oxygen-producing photosynthesis in cyanobacteria
M.R. Walter, B.A. Neilan, S.C. George, R.E. Summons, J.W. Schopf: Supported by ARC Discovery
Summary: The early Earth was a hostile place with little oxygen in the atmosphere. Then cyanobacteria (‘blue green algae’) invented oxygen releasing photosynthesis. That profound event affected many fundamental processes, from the course of evolution to the formation of ore deposits. However, estimates of when these bacteria originated are disputed with uncertainties of hundreds of millions of years. We will resolve those uncertainties. We have developed new analytical techniques that we will apply to well preserved 2.7-2.8 billion year old rocks in Western Australia. We will couple that approach to the use of the latest genetic techniques to reveal the origins of living cyanobacteria.
Investigation of the early history of the Moon: implications for the understanding of evolution of Earth and Solar System
A. Nemchin, M.L. Grange: Supported by ARC Discovery (commencing 2012)
Summary: The goal of the project is to characterise the chemistry and timing of processes that shaped the specific evolutionary path followed by the Moon during the early history of the Solar System. This is not only vital for evaluation of lunar history, but is also essential for a better understanding of early evolution of the Earth, where the record of the first 500 m.y. of history has been erased by the continuous activity of the planet. The project will test existing models of lunar evolution describing initial global differentiation, early plutonic magmatism, impact history and volcanic activity, shedding new light on the processes driving these major events on the Moon and determining the ability of these models to describe the early history of the Earth.
Supercells and the supercontinent cycle
W.J. Collins, J.B. Murphy, E. Belousova, M. Hand: Supperted by ARC Discovery (commencing 2012)
Summary: Phanerozoic plate motions can be explained by westerly and northerly migration of continental blocks toward Laurentia during protracted (~500 Ma) northerly mantle flow, confined within a hemispheric supercell. The other supercell on Earth encompasses the oceanic Pacific realm, characterised by E-W mantle flow diverging from the East Pacific Rise. We aim to determine if similar supercells and mantle flow patterns existed during the Proterozoic, by characterising contrasting orogenic systems within different supercells through tectonostratigraphic review, isotopic fingerprinting using Lu-Hf isotopes in zircon, and by paleomagnetic analysis. This is a new holistic approach to solving Precambrian geodynamics and continental reconstructions.
Investigating the fundamental link between deformation, fluids and the rates of reactions in minerals
S. Piazolo, N.R. Daczko, A. Putnis, M.W. Jessell: Supported by ARC Discovery (commencing 2012)
Summary: In Earth’s crust and mantle, minerals are constantly undergoing chemical changes while simultaneously being deformed. In this project we use a novel combination of techniques in order to advance our understanding of how deformation influences these chemical changes.
Dating Down Under: Resolving Earth’s crust - mantle relationships
E. Belousova: Supported by ARC Future Fellowship and MQ (commencing 2012)
Summary: How the continental crust has grown is a first-order problem in understanding the nature of the surface on which we live. Was most of the crust formed early in Earth’s history or did it grow episodically? Was its growth related to underlying mantle processes? The project will use in situ isotopic and trace-element microanalysis of the mineral zircon (a geological “time capsule”), extracted from rocks and sediments worldwide, to answer these fundamental questions. It will develop a new model for the timing of crustal formation and the tectonic and genetic links between Earth’s crust and mantle. The results will be relevant to the localisation of a wide range of mineral resources.
Strength and resistance along oceanic megathrust faults: implications for subduction initiation
C. O’Neill: Supported by ARC Future Fellowship and MQ (commenced 2010)
Summary: Plate tectonics is enabled by the sinking of dense oceanic lithosphere at ocean trenches - a process known as subduction, but how this process initiates is poorly understood. The development of an incipient subduction zone involves a major evolution of the plate boundary, into an oceanic megathrust fault system, capable of generating devastating earthquakes. An example is the Hjorta Trench, at the Australian-Pacific plate boundary south of Macquarie Island. This project will explore the evolution of this plate-boundary fault system during subduction initiation. Recent advances in our understanding of physical processes along plate-bounding faults will be incorporated into regional geodynamic simulations of this evolving fault system.
Flow characteristics of lower crustal rocks: developing a toolbox to improve geodynamic models
S. Piazolo: Supported by ARC Future Fellowship and MQ (commencing 2012)
Summary: This project will investigate in detail how rocks flow in the lowest part of the Earth’s crust. The results will be used to improve sophisticated computer simulations of large-scale geological processes, allowing a better understanding of earthquakes, the formation of volcanic areas and location of energy resources.
From Core to Ore: emplacement dynamics of deep-seated nickel sulphide systems
M. Fiorentini: Supported by ARC Future Fellowship (commencing 2012)
Summary: Unlike most mineral resources, which are generally concentrated in a wide range of crustal reservoirs, nickel and platinum are concentrated either in the core or in the mantle of our planet. In punctuated events throughout Earth history, large cataclysmic magmatic events have had the capacity to transport and concentrate these metals from their deep source to upper crustal levels. This project aims to unravel the complex emplacement mechanism of these magmas and constrain the role that volatiles such as water and carbon dioxide played in the emplacement and metal endowment of these systems.
Events through time: eruptions, extinctions, impacts, ore-bodies and orogenies - upgrading the national argon geochronology network
G.S Lister, F. Jourdan, M.A Forster, B.I McInnes, P.M Vasconcelos, G. Rosenbaum, D.R Cooke, A.C. Harris, D. Giles, A.S. Collins, J. Aitchison, N.R. Daczko, W.J. Collins, S.M. Reddy, Z.-X. Li, T.C. McCuaig, J.M. Miller, B.J. Pillans, R. Grun, H. Zwingmann, N.J. Evans, M.O. McWilliams (ARC LIEF, 2011)
Summary: Nine universities and the CSIRO will replace aged and obsolete equipment with new mass spectrometers which will be strategically placed at opposite ends of our continent to improve access for Australian researchers to these instruments for which there is high demand. These instruments will allow more exact dating of events such as eruptions, impacts, climate change, biological extinctions, mineral deposits and mountain building.
Nanoscale Characterisation Centre WA analytical electron microscope facility (UWA)
D. Sampson, M. Fiorentini, Y. Liu, R.J. Gilkes, B. Rasmussen, Z. Rengel, N.J. McNaughton, C. Kirkland, S.A. Wilde, M.T. Wingate, Z. Xie, R.C. Thompson: Supported by ARC LIEF
Partner/Collaborating Organisation(s): Geological Survey of Western Australia, Curtin University of Technology, Edith Cowan University, Murdoch University
Summary: This analytical facility for Western Australia will provide researchers with much needed access to new electron microscope instrumentation. The facility will support major research efforts in key disciplines, including minerals and mining, energy, engineering, nanotechnology, medical science, forensics, agriculture and animal science.
Tectonic evolution and lode gold mineralisation in the Southern Cross district, Yilgarn Craton (WA): a study of the meso- to Neoarchaean missing link
Barley, McCuaig, Gessner, Miller, Tohver, Doublier, Romano, Doublier: Supported by ARC Linkage
Summary: The primary objective of this study is to develop a superior tectono-metamorphic model to capture the geological evolution of the gold-endowed Youanmi Terrane in the Yilgarn Craton of Western Australia. The structural relationship between Archean (i.e. > 2,500 million years ago) greenstone belts and adjacent granitoids is critical to unravel the crustal evolution of the Early Earth and understand the formation of gold deposits. Based on a multidisciplinary approach, this project will generate an improved metallogenic model to help target areas of high prospectivity for gold mineralisation in Western Australia and world-wide.
A novel approach for economic uranium deposit exploration and environmental studies
S. Turner, B. Schaefer, G. McConachy: Supported by ARC Linkage and Quasar Resources (commenced 2009)
Summary: The project proposes the use of a novel approach to prospect for economic uranium ore deposits. The measurement of radioactive decay products of Uranium in waters (streams and aquifers) and sediments will allow us to (i) identify and locate economic uranium ore deposits, and (ii) quantify the rate of release of uranium and decay products during weathering and hence the evolution of the landscape over time. In addition, this project will improve our knowledge on the mobility of radioactive elements during rock-water interaction, which can be used to assess the safety of radioactive waste disposal. Outcomes of this project will be: (i) the discovery of new economic uranium deposits; (ii) development of a new exploration technology allowing for improved ore deposit targeting. Information gained on the behaviour of radioactive elements at the Earth’s surface will be critical for the study of safety issues related to radioactive waste storage and obtaining reliable time constraints on the evolution of the Australian landscape.
Composition, structure and evolution of the lithospheric mantle beneath southern Africa: improving area selection criteria for diamond exploration
W.L. Griffin, S. O’Reilly, N. Pearson: Supported by ARC Linkage and De Beers Group Services (commenced 2009)
Summary: Trace-element analyses of garnet and chromite grains from kimberlites distributed across the Kaapvaal craton and the adjacent mobile belts will be used to construct 2D and 3D models of compositional and thermal variation in the lithospheric mantle (to ~250 km depth), in several time slices. Regional and high-resolution geophysical datasets (e.g. seismic, magnetotelluric, gravity) will be used to test and refine this model. Links between changes in the compositional structure of the lithospheric mantle and far-field tectonic events will be investigated using 4-D plate reconstructions. The results will identify factors that localise the timing and distribution of diamondiferous kimberlites, leading to new exploration targeting strategies.
The first Australian high pressure Synchrotron facility for geoscience research
T. Rushmer, H.S. O’Neill, A.R. Cruden, S.P. Turner (ARC LIEF 2012)
Summary: In high-pressure mineral physics and chemistry, mineral properties, stress-strain relationships and processes like partial melting are applied to geophysical research about the deep Earth. This project will provide a large volume, high pressure capability at the Australian Synchrotron which will allow these mineral properties to be measured under conditions which simulate the deep earth.
Flexible architecture high-performance computing facility for the intersect consortium of New South Wales
L. Radom, I.H. Cairns, J.W. Crawford, L. Shen, C.M. Wade, M.R. Wilkins, H.A. Abbass, A.S. Dzurak, J.P. Evans, W. Wen, C.G. Poulton, M.D. Arnold, L.C. Botten, M.J. Ford, A. Rahmani, C.J. O’Neill, K.K. Cheung, M.E, F.A. Henskens, J.M. Borwein, T.R. Marchant, M. Hagenbuchner, K.A. Tieu, A.L. Rose, S.A. Gillies, P.L. Harrison, D.L. Waters, G. Leedham, R.D. Murison (ARC LIEF 2011)
Partner/Collaborating Organisation(s): Macquarie University, Southern Cross University, The University of Newcastle, The University of New England, The University of New South Wales, University of Technology, Sydney, University of Wollongong
Summary: This new supercomputing facility is an important addition to the nation’s research infrastructure and will enable world-leading, New South Wales researchers to continue their ground breaking work in increasingly competitive environments. Much of the research to be undertaken at the facility lies in areas of national priority, including frontier technologies and environmental sustainability.
How does the continental crust get so hot?
C. Clark: Supported by ARC DECRA (commencing 2012)
Summary: This project is aimed at constraining the tectonic drivers of high geothermal gradient crustal regimes. The key outcomes of this project are better constraints on the tectonic drivers of high geothermal gradient metamorphism and the development of quantitative tools to assess the evolution of heat within areas of mountain building.
Tectonic setting and evolution of the Paleoproterozoic Jiao-Liao-Ji Belt in the Eastern Block of the North China Craton
G. Zhao, S.A. Wilde, S. Li, and X. Li: Supported by HK RGC GRF (Project code: HKU7057/08P); (commenced 2009)
Summary: The Jiao-Liao-Ji belt is one of three Paleoproterozoic mobile belts in the North China Craton. Previous studies have suggested it formed in an extensional regime, in contrast to the collisional origin proposed for the Khondalite Belt and the Trans-North China Orogen. The well-exposed central part contains the Liaoji Granitoids and the North and South Liaohe Groups. The Liaoji granitoids record two ages: 2.2–2.1 Ga from monzogranitic gneisses and 1.88–1.85 Ga from porphyritic monzogranites and alkaline syenites. The North and South Liaohe Groups consist of volcano-sedimentary sequences metamorphosed from greenschist to lower amphibolite facies. Zircons from both groups have magmatic cores that define two age populations: at 2.5 Ga and 2.2–2.0 Ga, indicating provenance from late Archean basement rocks and the Liaoji Granitoids. Zircon rims in both groups yield ages of ~1.95 Ga, interpreted as defining peak metamorphism. Metamorphism was thus coeval with that in the Khondalite Belt in the Western Block of the North China Craton. Protoliths of both groups appear to have been deposited coevally between 2.1–1.9 Ga and similar Hf model ages and εHf values confirm this conclusion.
Facility for long term preservation and storage of biological, chemical, environmental and geological samples
Nevalainen, Packer, Karuso, Jamie, Molloy, Brown, Liu, Herbert, George, Vemulpad: Supported by Macquarie University Research Infrastructure Block Grants (RIBG)
Summary: Funds will be used to establish an integrated facility for safe preparation and preservation (freeze drying) and long term (-80 °C) storage of precious biological, environmental, geological and chemical samples. These materials are the result of longstanding and recently established research of biological, medical and environmental significance, and form the basis for future research and new IP. In recent years, we have lost various precious samples due to lack of and breakdown of freeze driers and freezers. The need for cryo-preparation and storage facilities is therefore acute, especially with the recent appointment of CORE researchers and concurrent significant increase in research activity.
Hydrothermal footprints of magmatic nickel sulfide deposits
M. Fiorentini, S. Barnes, Miller: Supported by MERIWA, WA State Gov.
Summary: (MERIWA M413) This study focuses on the mineralogical and lithogeochemical footprints around syngenetic magmatic nickel-sulphide deposits, which arise from the interaction of these deposits with later hydrothermal fluids. Hydrothermal footprints are in common use in gold and Cu-Zn exploration, but have so far received little attention from nickel explorers, mainly because the nature and the scale of the alteration halo are largely unconstrained. This study addresses this window of opportunity: The new knowledge acquired from this study will aid exploration for nickel-sulphide systems at multiple scales, and will be applied in the interpretation of isolated “orphan” drill holes under cover in greenfields terranes, as well as in more data-rich mine-scale environments.
Nature of the lower continental crust
N. Dazcko: Supported by MQSN grant (commencing 2011)
Summary: Despite its importance to the study of crustal evolution and geodynamics, the composition of the lower part of the Earth’s crust remains poorly known. This project utilises rare exposures of omphacite granulite in the natural laboratories of Fiordland, New Zealand and Hengshan Mountains, China to explore its influence on the composition, mineralogy and physical properties of the lower crust. The outcomes include characterisation of the rock types formed, their history and depth-temperature field of stability, and the determination of how omphacite granulite affects the strength of the crust and provides a fertile lower crustal source for magma.
Laser ablation microprobe sample cell
S.Y. O’Reilly: Supported by MQRIBG O’Reilly (commencing 2011)
Summary: Funds are requested for a new-design large-format sample-cell to upgrade one of the existing laser microprobes that is used in the microanalysis of trace elements and isotope ratios in minerals. These types of data are fundamental to the majority of the current ARC Discovery and Linkage projects in GEMOC, the new CoE and the EAPE CoRE. The new sample-cell will provide significant benefits for data quality, spatial resolution and increased sample throughput. The combination of these factors will enable significant improvement in current methods, sensitivity and productivity, and development of new analytical procedures that will enhance future research capabilities.
Understanding the growth of the Tibetan Plateau: Unveiling the final-scale 3D structure of the crust and upper mantle beneath the Tibetan Plateau
Y. Yang: Supported by MU New Staff Scheme
Summary: The Tibetan Plateau is the highest and largest plateau in the world with an average elevation of about 4-5 km, and it is still growing vertically and laterally. How such a broad and highly elevated plateau formed and persisted, however, is still not well understood. This project investigates the fine-scale 3D structures of the crust and upper mantle beneath the Tibetan Plateau using innovative tomography methods and extensive and dense coverage of seismic stations. The outcomes of this project will shed new insights on fundamental questions regarding the growth of the Tibetan Plateau.
Resurrecting Rodinia? The role of east Antarctica in supercontinent assembly
N. Daczko: Supported by ARC MQRDG (commenced 2010)
Summary: This project will determine the role of east Antarctica in the Rodinian supercontinent that assembled 1300-900 million years ago. Controversy exists regarding the timing of geological events in east Antarctica and how these relate to the architecture of the Rodinian supercontinent. This project will characterise the age and geochemical signature of key Precambrian rocks in Kemp and MacRobertson lands, which outcrop as islands, isolated nunataks and mountain ranges, and compare their evolution with proposed conjugate regions in India, Australia and broader Antarctica. These rocks will provide a missing link between disparate terranes in recent tectonic reconstructions of Rodinia.
AuScope Australian Geophysical Observing System - Geophysical Education Observatory
C. O’Neill: Supported by EIF
Summary: AuScope Australian Geophysical Observing System is designed to augment existing NCRIS AuScope infrastructure with new capability that focuses particularly on emerging geophysical energy issues. It will build the integrated infrastructure that facilitates maximum scientific return from the massive geo-engineering projects that are now being considered – such a deep geothermal drilling – in effect building the platform for treating these as mega geophysical science experiments. AuScope AGOS infrastructure will enable collection of new baseline data including surface geospatial and subsurface imaging and monitoring data, thereby providing for better long-term management of crustal services, particularly in our energy-rich sedimentary basins. The Geophysical Education Observatory – comprising the development of digital real-time connection to existing teaching laboratories, will use the national observatory to provide a unique opportunity for integrating scientific research and education by engaging students, teachers, and the public in a national experiment that is going on in their own backyard.
The thermal evolution of Peninsula India: Past behaviours and future potential
A. Collins, M. Hand, D. Kelsey, G. Baines, G. Backe, G. Halverson, (McGill Uni, Canada), C. Clark, S. Reddy, P. Kinny, N. Timms (Curtin Uni), Chetty, Sukanta Roy, Babu, Rajendra-Prasad, Singh, Harinarayana, Bhaskar Rao (National Geophysical Research Institute, India), Gupta, Mumtani, Panigrahi (Indian Institute of Technology, Kharagpur), Bhattacharya, Saha, Patranabis-Deb (Indian Statistical Intitute, Kolkata): Supported by Department of Innovation, Industry, Science and Research – Australia – and Department of Science and Technology – India – Strategic Research Fund Award (Commenced 2009)
Summary: The roots of southern Indian mountain belts (orogens) have experienced extremely high crustal temperatures (>900°C) in the geological past that are at least in part due to the presence of detrital U, Th and K (i.e. radioactive heat-producing elements) caught up in sedimentary rocks deposited before the orogens formed. If equivalent-aged sedimentary rocks that occur outside of the orogens have the same sources, or deposits eroded from these orogens can be identified, southern India will have the potential for a significant geothermal ‘hot-fractured rock’ resource.
Probing the composition of the early Solar System and planetary evolution processes
S. O’Reilly, W. Griffin, N. Pearson, O. Alard, B. Ildefonse, S. Demouchy: Supported by ARC DIISR French-Australian Science and Technology Program (commenced 2010)
Summary: The aim of this project is to understand the origins and history of chondritic meteorites, the most primitive rocks in the solar system, and the stuff from which planets are made. An ongoing controversy about the relative ages and relationships between the different components of these primitive meteorites goes to the heart of models for the evolution of the Solar nebula and the generation of planets, including Earth. This controversy turns on the question of whether the various components of chrondritic meteorites have been formed separately in space and time, or have shared a common high-temperature history. To provide new constraints on this problem, we will focus on the chemical and micro-structural relationships between the chondrules and the very fine-grained matrix in which they are embedded. We will use both established and recently developed in situ microanalytical techniques, to measure the abundances and isotopic compositions of critical elements in the fine-grained minerals of chondrules and their matrix, and to determine the degree of structural alignment between the minerals in the two components. The data will be used to evaluate the degree of high-temperature interaction between chondrules and their matrix, and to assess different models for the formation of chondrites. The results will be compared with equivalent information on samples of the Earth’s deep interior brought to the surface in volcanoes or tectonic uplift; such samples can provide analogues for the differentiation of meteoritic parent materials. The project will use complementary equipment in France and Australia: (laser-ablation (LA) inductively coupled mass spectrometry (ICPMS) at GEMOC (Macquarie University); ion microprobe and electron backscatter diffraction (EBSD) at GM (Geosciences Montpellier, UMR 5342)).
Petrogenesis of Leiqiong flood basalts: constrain the potential linkage between mantle plume and subduction
J. Li, PI: X.-C. Wang: Supported by NSFC (commenced 2011)
Summary: Whether mantle plumes and plate subduction are genetically linked is a fundamental geoscience question that impinges on our understanding of how the Earth works. Late Cenozoic basalts in Southeastern Asia are globally unique in relation to this question because they occur above a seismically detected thermal plume adjacent to deep subducted slabs. This project will address a geodynamic model that links these two fundamental geotectonic processes.
Three-dimensional characterisation of brittle fault rocks
Gessner, Hough, Toy, Thebaud, Liu, Dellepiane, Zwingmann, Kopf: Supported by The International Synchrotron Access Program (ISAP)
Summary: Understanding the microstructure of fault rocks is highly relevant to geological applications such as carbon storage, hydrocarbon and geothermal reservoir characterisation, earthquake mechanics and mineral exploration. We propose to obtain micro-tomographic images of cataclasite and gouge samples from active natural faults in different settings and experimental samples using the XOR 2-BM at the Advanced Photon Source. Particles and porosity are analysed in three dimensions. This project will advance the understanding of fault rupture during earthquakes, and of the role that fault rocks play in the flow of fluids within Earth’s crust.
Archean subduction in the Kaapvaal Craton
M.J. van Kranendonk: Supported by UNSW SPF01 (commencing 2012)
Summary: This project will investigate claims of a fossil Archean subduction zone (ca. 3.2 Ga) within the Kaapvaal Craton of Southern Africa. Previous work has suggested the presence of such a structure based on interpreted metamorphic conditions preserved in amphibolites, but no convincing map of the area has been presented in which to place this claim in context. This project will map the area and determine the nature of the metamorphism within a regional structural and lithological framework.
The Archean-Proterozoic boundary in Western Australia
M.J. van Kranendonk: Supported by UNSW SPF01 (commencing 2012)
Summary: This project is aimed at investigating the changes wrought across the Archean-Proterozoic boundary in Western Australia, marking the transition from juvenile, reducing, early Earth to more modern, oxidised, adolescent Earth. Details of stratigraphy, stable isotope geochemistry, and paleontology will be examined and integrated into global events.
The Active Alpine Fault Zone as an analogy for fluid dynamics in Archaean mineral systems
K. Gessner, Thebaud, Toy, Ring: Supported by UWA Collaborative Research Fund
Summary: The circulation of hydrothermal fluids and their capacity to transport heat and solutes controls heat and mass transfer in the Earth’s crust. The genetic and spatial link between fault zones, fluid flow, and mineral deposits has been known for a long time, but there has been little systematic investigation into how deformation fabrics and chemical alteration of rocks interact in active fault zones. We propose to address this shortcoming by applying state of the art mineral mapping and x-ray tomography methods to characterise deformed and chemically altered rocks from the Alpine fault in New Zealand and from the Eastern Goldfields in Western Australia.
Geobiology of the 1900 Ma Gunflint Formation
D. Wacey, M. Brasier (international collaborator): Supported by UWA RCA
Summary: Using newly developed analytical capabilities we will increase our understanding of the most iconic Precambrian microfossil assemblage (The Gunflint Biota). In particular, SIMS, NanoSIMS and the use of the Focused Ion Beam in combination with Scanning and Transmission Electron Microscopy will enable us to study the microfossils and newly discovered phosphate minerals in situ, at higher resolution than previously possible, and in 3D. This work is essential if the Gunflint microfossils are to continue to serve as a useful baseline for future studies of putative Archean and extraterrestrial microfossils.
Petrogenesis of Cenozoic Inner Mongolia flood basalts: detecting the dehydration of stagnated Pacific slabs
X.-C. Wang: Supported by NSFC (commenced 2009)
Summary: Central and Eastern Asia has the largest and most poorly understood diffusive intraplate large igneous provinces (DLIPs). This project is designed to construct the primary melt compositions based on the published data and our new analysis and then to investigate the source, thermochemical state and water contents. This study showed that the central and eastern Asian Cenozoic basalts were produced by hydrated mantle source with about 0.2 wt.% H2O in the continental interior, and an increase up to about 0.5 wt.% in the margin of the Pacific back arc basin. The Cenozoic mantle beneath this region has a mantle potential temperature similar to MORB-type mantle. Thus, dehydration of stagnated slabs atop the mantle transition zone played an important role in producing the intraplate DLIPs.
Australian Drilling Program: Biomarkers, oxygen and geobiology
George, Dutkiewicz, Webb: Supported by Agouron Institute Research Grant (commenced 2010)
Summary: The project aims...
• To resolve whether Archean hydrocarbon biomarker molecules are indigenous or not,
• To obtain geobiological and redox-indicator samples in environmental and temporal context,
• From drill-cores of strata that are too weathered at the surface for reliable preservation of hydrocarbon biomarkers and other redox- sensitive biosignatures and environmental indicators,
• From rocks dating from before the ecological dominance of animals,
• With particular emphasis on time intervals and rock types relevant to the rise of oxygen,
• To complement and extend the environmental and stratigraphic range of samples obtained from the Agouron South African drilling program.