PhD proposal – Mohammed Alfitouri ‘Evaluating the response of Acacia trees in Southwest Australia under environmental stress’
Supervisors: A/Prof Grant Wardell-Johnson, Prof M. Gibberd
Where: 312:207
When: Tuesday 12th August, 16:00-1700
Enquiries to: A/Prof Grant Wardell-Johnson G.Wardell-Johnson@curtin.edu.au
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Wednesday 6th August 12 – 1 pm Rm 312.222 |
Zoja Vukmanovic Department of Applied Geology Morphology And Microstructures Of Chromite Crystals From The Merensky Reef: Implications For Inclusion Entrapment Mechanism Abstract
The Merensky Reef of the Bushveld Complex consists of two chromitite layers separated by coarse-grained melanorite. Microstructural analysis of the chromitite layers using electron backscatter diffraction analysis (EBSD), high-resolution X-ray microtomography and crystal size distribution analyses distinguished two populations of chromite crystals: fine grained idiomorphic and large silicate inclusion bearing crystals. The lower chromitite layer contains both populations, whereas the upper contains only fine idiomorphic grains. Most of the inclusion-bearing chromites have characteristic amoeboidal shapes that have been previously explained as products of sintering of pre-existing smaller idiomorphic crystals. Two possible mechanisms have been proposed for sintering of chromite crystals: 1) amalgamation of a cluster of grains with the same original crystallographic orientation; and 2) sintering of randomly orientated crystals followed by annealing into a single grain. The EBSD data show no evidence of recrystallization or clusters of similarly oriented grains among the idiomorphic population. An alternative model is proposed whereby silicate inclusions are incorporated during maturation and recrystallisation of initially dendritic chromite crystals, formed as a result of supercooling during emplacement of the lower chromite layer against cooler anorthosite during the magma influx that formed the Merensky Reef. The upper chromite layer formed from a subsequent magma influx, and hence lacked a mechanism to form dendritic chromite. This accounts for the difference between the two layers.
Biography Zoja joined Curtin University as a Research Associate in October 2013. She is working on emplacement of the Ivrea Verbano ultramafic pipes in Italy as a part of Core to Crust Fluid System project. She completed her BSc at University of Turin, Italy and MSc at Free University, Amsterdam, the Netherlands. She received her PhD at the University of Western Australia in 2013. |
The spread of urban areas negatively influences many species of animals. Some species, however, can adapt to urban living. Exploring the ecology and behaviour of two reptile ‘urban adapters’ in Perth will be the focus of this seminar.
Where: 312:207
When: Tuesday 5th August, 16:00-1700
Enquiries to: Dr Bill Bateman bill.bateman@curtin.edu.au
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Wednesday 30th July 12 – 1 pm Rm 312.222 |
Ken McNamara Department of Earth Sciences, University of Cambridge Effects of environmental changes on the evolution and extinction of Late Devonian trilobites, northern Canning Basin, W.A. Abstract
The Frasnian-Famennian Virgin Hills Formation represents fore reef facies deposited as part of the extensive Late Devonian reef system that fringed the south-western Kimberley Block in Western Australia. It contains a rich trilobite fauna dominated by proetids, and to a lesser extent, harpetids, phacopids, scutelluids and odontopleurids. To date 49 taxa have been described, 40 of these restricted to the Frasnian. Evolutionary trends in the Virgin Hills trilobites are dominated by reduction in body size and eye size, and, to a lesser extent, reduction in exoskeletal vaulting. Although recording no sedimentological signature, the fauna was strongly affected by the two globally recognized Kellwasser extinction events. The first, at the end of conodont Zone 12 affected taxa at the species and genus level. The second, at the end of Zone 13b, had a much greater impact, causing extinctions at the familial and ordinal levels. Evolutionary trends in the late Frasnian trilobites reflects selection for forms adapted to low nutrient conditions. The two intensive Kellwasser extinction episodes may reflect periodic massive inputs of nutrients from terrestrial into shallow marine environment.
Biography Ken is an Adjunct Professor at Curtin; Senior Lecturer in Earth Sciences at the University of Cambridge; Director of the Sedgwick Museum, University of Cambridge, and Dean and Fellow of Downing College, Cambridge. He was adjunct at Curtin for many years, teaching palaeontology, when he was Head of Earth & Planetary Sciences at the WA Museum. |
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Wednesday 23rd July 12 – 1 pm Rm 312.222 |
Paolo Raiteri Department of Chemistry and Nanochemistry Research Institute On the existence of prenucleation clusters of alkaline earth carbonates Abstract
Calcium carbonate (CaCO3) is arguably the most studied mineral because of its importance in industrial applications, geo-sequestration and bio-mineralisation. Despite this global interest a full understanding of the molecular mechanisms that control the nucleation and growth of CaCO3 is still elusive. Thanks to the constant increase of computational power, atomistic simulations have become an invaluable tool to help interpret the experimental results and we are now at a stage where computer simulations can make reliable predictions in areas not yet achievable by experiments.
In recent years the appearance of calcium carbonate stable clusters and of a dense liquid phase before the onset of nucleation has been proposed and verified, both experimentally and computationally [1-3]. This has led to a new picture of the formation pathway of carbonate minerals emerging. Initially, the ions aggregate to form dynamic chain like structures [1,2] (DOLLOP) that, upon increase in the ion activities, undergo a liquid-liquid phase separation to form a dense liquid phase [3]. This dense liquid phase progressively looses water and precipitates in the form of amorphous calcium carbonate, which eventually transforms into one of the commonly found anhydrous polymorphs.
This phenomenon is believed not to be limited to calcium carbonate, but to be a general growth mechanism for the formation of many minerals [4], such as the other alkaline earth carbonates, sulphates and phosphates. Here large-scale computer simulations can provide a unique opportunity to test this hypothesis. A carefully parameterised force field, which was calibrated against the thermodynamics of the species in solution and in the crystalline phases [5], has indeed been already used to study this very phenomenon for the calcium carbonate system [2,3].
[1] Gebauer et. al. (2008) Science. 322, 1819-1822. [2] Demichelis et. al. (2011) Nat. Commun. 2, 590. [3] Wallace et. al. (2013) Science, 341, 885-889. [4] Gebauer et. al. (2014) Chem. Soc. Rev., DOI: 10.1039/C3CS60451A. [5] Raiteri, et al. (2010) J. Phys. Chem. C, 114, 5997- 6010.
Biography Dr Paolo Raiteri obtained his MSc and PhD in Material Science from the University of Milano-Bicocca in 1999 and 2003, respectively. Successively he became a post-doctoral research assistant in the group of Prof Parrinello at ETH Zurich, who is a world leader in the field of Computational Chemistry. In 2008 Dr Raiteri moved to Curtin as an Early Career Research Fellow and in 2009 he became an ARC Research Fellow (ARF). From January 2014 Dr Raiteri is an ARC Future Fellow and Senior Research Fellow at Curtin University. Dr Raiteri has so far published 59 papers in peered-reviewed journals, including Science, Nature and Nature Communications and a WoS h-index of 19. |
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Wednesday 9th July 12 – 1 pm Rm 312.222 |
Simon Lewis Department of Chemistry, Curtin University Contacts Leaving Traces: Synchrotron source infrared spectroscopy of forensic exchange evidence Abstract Locard’s Exchange Principle is a key tenet of forensic science, and is relied upon by forensic investigators in order to establish links between persons, objects and locales. This presentation provides an overview of our recent studies utilising the Infrared beamline at the Australian Synchrotron to study various forms of exchange evidence. Synchrotron infrared (IR) microscopy is ideally suited for this research due to its high spatial resolution and improved sensitivity compared to conventional IR microscopy. We have used high spatial resolution synchrotron source transmission IR spectra of paint thin sections to examine the migration of components between the various paint layers [1] and to study primer surfacer coats from a large population of vehicles of known origin [2]. Using chemometrics the primer surfacer data was classified into 14 groups that related to the country of manufacture, manufacturer and manufacturing plant, and in some cases an indication of the year of manufacture [2]. The successful development of latent fingermarks relies heavily upon the chemistry of the latent fingermark residue itself. We have used synchrotron IR microscopy to study the chemical composition of latent fingermarks, with particular regard to the ageing of the fingermark [3]. [1] Maric, M., van Bronswijk, W., Lewis, S. W., & Pitts, K. (2014). Synchrotron FTIR characterisation of automotive primer surfacer paint coatings for forensic purposes. Talanta, 118(0), 156-161. Biographical Details Simon Lewis is Professor of Forensic and Analytical Chemistry and Director of Teaching and Learning in the Department of Chemistry at Curtin University, Perth, Western Australia. He obtained a his PhD in Analytical Chemistry from the University of Plymouth, UK before taking up a position as a lecturer at Deakin University, Geelong, Australia (1994-2005) where he was involved in developing and coordinating the undergraduate forensic science program . His research is focused on chemical techniques applied to forensic analysis and has been carried out in collaboration with various forensic science providers including ChemCentre, Western Australia Police, AFP, Forensic Science South Australia, Victoria Police Forensic Services Department and the US Secret Service. He has published in excess of 80 peer reviewed papers and book chapters in the areas of analytical and forensic chemistry. His research on fingerprint detection has resulted in invitations to present at meetings of the International Fingerprint Research Group (IFRG), in Canberra, Australia (2007), Lausanne, Switzerland (2009), Linkoping, Sweden (2011) and most recently in Israel (2013). Attendance at an IFRG meeting is by invitation only and represents recognition of relevant research contributions in the field. He is on the editorial advisory boards of the Journal of Forensic Identification and the recently published Elsevier Encyclopedia of Forensic Sciences (2nd Edition) (with specific responsibility for Analytical Techniques). Prof Lewis currently serves on the Program Advisory Committee for the Infrared Beamline at the Australian Synchrotron. In addition to his research and teaching he is enthusiastically involved in out-reach programs, using forensic science and analytical chemistry as vehicles to engage children of all ages in science. His activities in forensic science and chemistry education have been recognised by a number of awards at the university and national level including in 2009 an Australian Learning & Teaching Council (ALTC) Award for Teaching Excellence in the category of Physical Sciences and Related Studies. |
| Wednesday 25th June
12 – 1 pm Rm 201.322 |
Louise Fisher CESRE, CSIRO Case studies from the XFM beamline at the Australian Synchrotron – high resolution, quantified whole thin-section mapping of geological samples Abstract The first part of this talk will aim to give a broad overview of the available beamlines at the Australian Synchrotron and a brief introduction on how to access them. The second half of the talk will focus on the X-Ray Fluorescence Microscopy (XFM) beamline and review recent case studies of samples from Au and PGE systems to show how the ability to collect elemental maps at 2 micron resolution at whole-thin section scale can change our understanding of alteration and mineralisation processes. |
| Wednesday 4th June
12 – 1 pm Rm 312.222 |
Diana Plavsa Curtin University, Dept. Applied Geology The tectonic evolution of the Southern Granulite Terrane of India and its role in the amalgamation of Gondwana Abstract The southernmost portion of the Indian subcontinent, the Southern Granulite Terrane of India, holds a pivotal role in the reconstructions of the Ediacaran-Cambrian supercontinent Gondwana. Bound to the west by Madagascar and the East African continental fragments and to the east by Sri Lanka and Antarctica, this terrane offers a breadth of information regarding across terrane correlations and palaeotectonic settings. Arguably, within the Southern Granulite Terrane of South India, the most debated issue of all is the existence of a late Neoproterozoic (ca. 550 – 500 Ma) suture zone between the Salem and Madurai Blocks, termed the Palghat Cauvery Shear Zone (or alternatively, the Cauvery Shear Zone). Biographical Details
Diana recently joined Curtin University as a Postdoctoral Research Associate on the Distal Footprints Science and Industry Endowment Fund (SIEF) research project looking at the tectonic evolution of the Capricorn Orogen. Prior to her arrival at Curtin, she completed a BSc (Hons) at the University of Adelaide in 2005. At the completion of her studies, she went on to work in the mining industry (including coal mining and gold exploration in Queensland and Northern Territory respectively) for 3 years. She then returned to the University of Adelaide to complete her PhD in 2014. |
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Friday 23rd May 10 – 11 am Rm 312.207 |
Chris Marone Curtin University, Dept. Applied Geology Slow Earthquakes and Weakness of Major Tectonic Faults: Connections Between Fault Strength, Fabric, and the Mode of Frictional Sliding Abstract Earthquakes have long been understood as frictional stick-slip instabilities in which stored elastic energy is released suddenly, driving catastrophic failure. In normal earthquakes the rupture zone expands at a rate of a few km/s, as dictated by elastic wave speed, and fault slip rates reach 1-10 m/s. However, tectonic faults also fail in slow earthquakes with rupture durations of months or more and fault slip speeds of ~100 µm/s or less. Slow earthquakes and other forms of transient fault slip can rupture large fault regions, reaching the equivalent of M 8 or larger. They can transfer stress to the seismogenic zone and thereby trigger damaging, normal earthquakes. In this talk, I discuss slow earthquakes and the spectrum of fault slip behaviors in the context of new results on the role of shear fabric and hydrous clays in determining fault strength and slip behavior. The results on fault strength provide an explanation for the heat flow paradox in central CA and slip on low angle normal faults. Our work shows that fault zone fabric and the presence of clay nanocoatings can cause extreme fault weakness. The extent to which this mechanism operates at greater depths remains an open question. I also summarize recent results showing the first laboratory observations of repetitive, slow stick-slip in fault zone materials, and mechanical evidence for their origin. The experiments were conducted on serpentine fault gouge under stresses appropriate for slow earthquakes in nature. The laboratory slow slip events are accompanied by precursory elastic wave speed reduction that begins up to 60 seconds before failure. We documented a transition from unstable to stable frictional behavior above a threshold velocity of ~10 µm/s. These data provide direct evidence for the hypothesis that slow earthquakes represent prematurely-arrested normal earthquakes. Biographical Details
Chris Marone is associate head at the Department of Geosciences at Pennsylvania State University. His research encompasses the physics of friction, earthquake mechanics, physico-chemical aspects of rock deformation, granular mechanics, rock-fluid interactions, permeability of geomaterials, fault mechanics, rheology, constitutive laws, and postseismic deformation. |
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