PSI Student Projects
Supervisors: Dr. Yuri Amelin, Prof. Trevor Ireland
An interstellar molecular cloud transformed into our Solar System through condensation of mineral grains, accretion and growth of planetesimals and planets in a short period of a few million years. Understanding the nature of these events is impossible without their precise sequencing. The aim of this project is to determine the timing and duration of the key events of accretion and planetary growth with precision and accuracy hitherto unattainable.
The student will analyse some of the best preserved meteorites and their components (minerals, chondrules, refractory inclusions) for U-Pb, 26Al-26Mg, 53Mn-53Cr and 182Hf-182W using high-precision and high-resolution analytical techniques: thermal ionisation and plasma ionisation mass spectrometry and SHRIMP ion microprobes. The project involves extensive laboratory development work in order to maximize precision, accuracy and sensitivity of isotopic methods.
Supervisors: Dr. Yuri Amelin, Prof. Trevor Ireland
All chemical elements heavier than lithium, that comprise the Earth and our Solar System, were produced by nuclear reactions in stars, and mixed during formation of the Solar System. It was once thought that that mixture once existed as a hot and almost homogeneous molecular cloud, and the minerals, planetesimals and planets formed during its cooling and gradual condensation and accretion. That concept was overthrown by discovery of refractory materials (Ca-Al-rich inclusions and hibonite grains) containing isotopic anomalies that are incompatible with condensation from homogeneous 'bulk solar' gas. Existence of presolar grains with extreme isotopic compositions for many elements, and small but systematic differences in isotopic compositions of Mo, Cr, Ni, Ba and other elements between Earth, Mars, and meteorites from various asteroids demonstrates heterogeneity of the Solar System at scales from micron-sized minerals to planets. The pattern of mixing, however, remains poorly understood. The student will explore the timing of mixing nucleosynthetic components and mechanisms of homogenisation by precise isotopic analysis of several elements containing isotopes produced in various stellar environments from selected meteorites, and by comparative modelling of mixing and mass-independent fractionation that can possibly mimic incomplete mixing. The main emphasis can be given to either an analytical or a modelling part, depending on the talents and skills of the student.
You can join us as a Honours, M.Sc. or PhD student at Research School of Earth Sciences or Research School of Astronomy and Astrophysics! We have many interesting projects waiting for talented students. We highly recommend you make contact with an academic staff member to discus potential projects.
Supervisor: Bennett, Victoria, Norman, Marc
Samples of moon rocks and regolith collected during the Apollo Missions as well as the lunar meteorites discovered on Earth allow us to study the origin and geology of the Moon directly. The most striking lunar features, clearly visible in the night sky are the large mare basins that formed when a rogue population of asteroids struck the Moon about 3.9 billion yars ago. We are using the chemistry of lunar impact melt rocks, in particular the concentrations of the highly siderophile platinum-group elements, to determine the types of asteroids that created these large (300-2500 km diameter) impact basins. This in turn will tell us about the types of planetesimals traversing the inner solar system at that time, and likely hit the Earth as well. This is largely a laboratory based project (no field work planned right now) and requires a person who wants to learn leading-edge chemical techniques, is a good observer with excellent attention to detail, and thinks big picture. This is just one of many potential projects working on lunar samples.
Supervisors: Dr. Yuri Amelin, Prof. Trevor Ireland
Knowing the distribution of U, Th and radiogenic Pb in chondrules and refractory inclusions is important for accurate interpretation of U-Pb isotopic dates. For example, the distribution of U between primary and secondary minerals can indicate whether the date corresponds to formation or to alteration of a chondrule or a Ca-Al-rich refractory inclusions (CAIs). In the case of dating equilibrated (i.e. metamorphosed) chondrites, we need to know the host mineral of U in order to apply correct diffusion parameters for estimating closure temperatures.
The student will explore and advance the sensitivity limits of modern secondary ionisation mass spectrometry, and will use this technique to measure U, Th and Pb concentrations and isotopic ratios in chondrules, CAIs and their components. Extremely low concentrations of U and Th in chondrites in a low parts per billion range, together with micron-scale heterogeneity of chondrules and CAIs makes this project analytically challenging.
Supervisor:Norman, Marc
Lunar soils carry a remarkable record of volcanic eruptions and meteorite impacts that occurred on the Moon over the past four billion years. These events can be studied by analysing small fragments of volcanic and impact glass found in the lunar soils. For this project you will measure 39Ar-40Ar ages and chemical compositions of individual glass beads from lunar regolith collected at each of the six Apollo landing sites. This will allow us to distinguish volcanic from impact events and evaluate the efficiency of sediment transport on the Moon. This project will position you well to participate in the upcoming decade of international space exploration and resource utilisation on the Moon and Mars. The project will suit someone with an interest in planetary science, a good knowledge of basic geochemistry, and a steady hand. The image shows a picture of moon rock 67016. It is an impact breccia that was collected at the Apollo 16 landing site.
