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Research Projects at RSES Research Projects at RSES
Exploring potential and limitations of ultrahigh-precision U-Pb dating
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Supervisor:Amelin, Yuri Williams, Ian Rubatto, Daniela
Subject keywords: Geochronology (dating), Planetary studies, Deep Earth/Continent evolution, Petrology, Chemistry, Geochemistry, Geology, Physics, Laboratory, Analytical
Degree types: M.Sc, PhD,
The goal of this project is to enhance our ability to solve geological problems with more precise and accurate isotopic dating. Geochronology allows us to determine which of the geological events close in time occurred first, and thus to constrain their causal relations. With precision of dating of 0.1-0.2 million years, we can verify the links between mass extinctions and impact events or catastrophic volcanic eruptions, pinpoint geological processes responsible for formation of major ore deposits, and solve other important scientific and practical problems, which cannot be solved reliably with 20-50 times less precise microbeam techniques, currently adopted by the Australian geological community. The student who undertakes this project will comprehensively evaluate the accuracy (and various possible causes of inaccuracy) in U-Pb dating at the new level of precision, in order to establish a procedure for routine dating of Precambrian zircon and other minerals with precision and accuracy of ±0.1-0.2 Ma, or about 3-10 times better than before. This project is most suitable for a student who is interested in both the history of the Earth, and in solid state chemistry and physics.
Calibration of thermo-barometers for deeply subducted rocks
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Supervisor:Hermann, Joerg Rubatto, Daniela ONeill, Hugh
Subject keywords: Deep Earth/Continent evolution,Petrology,Geochronology (dating),Geochemistry,Geology,Experimental,Analytical,Fieldwork,
Degree types: PhD,
The finding of metamorphic coesite and microdiamonds in gneisses completely changed the ideas of geologists concerning subduction of continental crust. These minerals provide evidence that crustal rocks were subducted up to 130 km depth and later exhumed to Earth's surface. Because of the scarcity of experimental data for felsic crustal rocks in diamond-facies conditions, up to now proof of diamond-facies metamorphism is restricted to rocks actually containing microdiamonds. In the proposed project new thermobarometers for crustal ultra-high pressure (UHP) rocks will be tested and developed using the main UHP mineral assemblage garnet-phengite-kyanite-clinopyroxene-coesite-rutile-zircon-apatite. The project includes experimental petrology, detail chemical characterisation of experiments and natural rocks and thermodynamic analysis.
Monitoring high grade metamorphic processes with accessory phases
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Supervisor:Hermann, Joerg Rubatto, Daniela ONeill, Hugh
Subject keywords: Deep Earth/Continent evolution,Petrology,Tectonics/Earth Deformation/faults,Geochronology (dating),Geochemistry,Geology,Laboratory,Experimental,Analytical,Fieldwork,
Degree types: PhD,
In this project we propose an interdisciplinary approach to develop new and innovative tools for high-resolution investigation of partial melting and high-grade metamorphism. These tools are based on recent findings that trace elements, due to their slower diffusion, are the most retentive record of metamorphic processes. The stability of accessory phases, which are commonly the major hosts of trace elements, will be studied in natural rocks and experiments, particularly to investigate the potential of such phases to buffer trace element contents of partial melts. The project includes experimental petrology, detail chemical characterisation of experiments and natural rocks and analysis of trace element partitioning.
Tracing fluids and rare elements in the crust by combining microscale oxygen isotope analysis with geochronology
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Supervisor:Rubatto, Daniela
Subject keywords: Geochronology (dating), Deep Earth/Continent evolution, Petrology, Geochemistry, Laboratory, Analytical, Fieldwork
Degree types: Honours, PhD,
Aqueous fluids play a critical role during metamorphic processes in the Earth’s crust because they have first order influence on element transport, reaction kinetics and heat transfer. Understanding their fluxes, sources and interaction with minerals is fundamental for the comprehension of these processes. The interaction between rocks and aqueous fluids is best investigated through a multidisciplinary approach with particular emphasis on oxygen isotopes. During this project you will be part of a team effort to develop protocols and knowledge for microscale analysis of oxygen isotopes to investigate fluid fluxes and their interaction with minerals containing rare elements. You will: combine fluid tracing with age determinations at the microscale to establish the timing to fluid circulation; Integrate oxygen and age data with petrology and trace element analysis in order to determine when and how rare elements are mobilized during metamorphism; Apply these methods to case studies where fluids play an important role in the geological processes, including regional metamorphic sequences, subduction and ore deposits. The project will include field-work in one or more localities in Australia and around the world. An important component of the project will be laboratory analysis using a variety of instruments from SEM to LA-ICPMS and particularly SHRIMP ion-microprobe, all located at RSES.
The student will