UCD School of Scoil na nEolaíochtaí
Geological Sciences Geolaíochta UCD
UCD Science Education and Ionad Léann agus Thaighde
Research Centre (West), Eolaíochta UCD (Iarthar),
University College Dublin, An Coláiste Ollscoile, Baile Átha Cliath,
Belfield, Dublin 4, Ireland Belfield, Baile Átha Cliath 4, Éire
T +353 1 716 2331 geology@ucd.ie
F +353 1 283 7733 www.ucd.ie/geology
PhD Research Opportunities 2009
The UCD School of Geological Sciences invites immediate applications for the PhD projects listed below. The School has an international reputation for excellence in research. This is reflected in the number and quality of publications and in the levels of research funding received from a wide range of sources. Research on a variety of themes within geological sciences is carried out by the academic staff, postdoctoral fellows and postgraduate research students. Our researchers comprise a large and cosmopolitan group and we pride ourselves on our friendly atmosphere of support and cooperation. If you would like to further your studies in a dynamic research environment, the UCD School of Geological Sciences may be the place for you.
We regret that due to funding restrictions, these projects are only available to EU citizens.
It is intended that the PhD Research projects listed will commence in October 2009. If you are interested in any of these projects, you should e-mail the contact supervisor for further information - deadline for application is Wednesday 8th July.
Numerical modelling of fault segment interaction and linkage using the Discrete Element Method.
Supervisors: Prof. John J. Walsh, Dr Conrad Childs, Dr Martin Schöpfer
Contact: john@fag.ucd.ie
Project Description:
Geological faults localise as arrays of fault segments, which with progressive growth become more linked and through-going. The fundamental controls on the deformation and linkage at fault segment boundaries are, however, relatively poorly understood. This project will investigate the growth, internal structure and linkage of segment boundaries using the Discrete Element Method (DEM). The research results will provide a mechanical basis for established conceptual models of fault segment growth and linkage, and will have implications for both the earthquake behaviour and the associated fluid flow characteristics of geological fault systems.
The nature and origin of fault surface corrugations.
Supervisors: Prof. John J. Walsh, Dr Conrad Childs, Dr Andy Nicol (GNS Science, New Zealand)
Contact: john@fag.ucd.ie
Project Description:
Fault surface corrugations parallel to the fault slip direction are observed on a wide range of scales from laboratory (mm-scale) experiments, outcrop exposures of fault surfaces through to seismically imaged faults (km-scale). Corrugations can form by a number of processes. Studies of large scale, sometimes seismically imaged, corrugations have tended to conclude that they arise from the linkage of initially unconnected fault segments, while smaller, outcrop-scale, corrugations have been attributed to wear mechanisms. To date, there has been little attempt to rationalise the scaling relationships of these, and other, corrugation-forming processes. This project will use fault surface geometrical data derived from laboratory, outcrop and 3D seismic reflection surveys to quantitatively characterise fault surface geometry over the complete scale range. These data, combined with detailed analysis of the internal geometry of outcropping fault zones and kinematic analysis of seismically imaged faults, will be used to define the processes controlling fault surface corrugation over the complete scale range.
Geometrical upscaling for faults in clastic flow simulation models.
Supervisors: Prof. John J. Walsh, Dr Tom Manzocchi, Dr Conrad Childs
Contact: john@fag.ucd.ie
Project Description:
It is often problematic to represent the geometry of geological features within the models of reservoirs generally used to assess hydrocarbon recovery. The aims of this research are therefore to develop methods and procedures for representing effects of complex but systematic, three-dimensional fault permeability structure at the lower resolutions and dimensionalities used in full-field numerical flow simulation. The wide range of issues associated with this topic will be considered, ranging from field-based geological characterisation/mapping, through geometrical parameterisations and upscaling, to numerical flow simulation. Existing in-house and industry-standard software will be used in conjunction with the newly-developed methods to formalise procedural advances.
Modelling sandstone connectivity in deep-marine depositional environments.
Supervisors: Prof. John J. Walsh, Dr Peter D.W. Haughton, Dr Tom Manzocchi
Contact: john@fag.ucd.ie
Project Description:
Improvements in our understanding of the controls on bed-scale compartmentalisation in faulted and unfaulted turbidite sequences could be of great importance in many emergent hydrocarbon provinces. Simplified sheet-like systems have strong parallels with continuum percolation models and therefore have well-established controls on sandstone connectivity. This project will focus on assessing the influence on connectivity of systems with more diverse and geologically reasonable associations of sedimentation and erosion. The role that faults of different sizes have on modifying sandstone connectivity is recognised to be complex, and there are still many unresolved questions, particularly concerning the effects of syn-sedimentary faults. Connectivity issues will be explored in 1D, 2D and 3D using purpose-built code, and learnings from the research may be used to guide innovative and industry-standard modelling practices.
Fate of low density clay clasts and particulate organic carbon entrained in turbidity currents.
Supervisors: Dr Peter D.W. Haughton and Prof. William McCaffrey (TRG, University of Leeds, UK)
Contact: peter.haughton@ucd.ie
Project Description:
Many turbidity currents transport significant clay clasts and particulate organic carbon in addition to silicate or carbonate mineral grains. The clay clasts are entrained by erosion up-dip and are important because they can participate in transformations in flow behaviour down dip, particularly where they disaggregate to generate a clay suspension that can suppress turbulence. The particulate organic carbon ultimately has a terrestrial origin and its transfer off the shelf in gravity currents in an understudied aspect of the global carbon cycle. This project will (1) investigate the transport and disaggregation of clay clasts in turbulent currents, focussing on hydraulic segregation over different bedforms, clast disintegration mechanisms and the implications for flow behaviour. Efficient segregation of clay chips and organic flakes is important to the resulting reservoir quality. (2) examine the inventory and budget of particulate organic carbon that is often partitioned with the clay component at the distal end of the flow pathway. The project will utilise a combination of laboratory experiments (to be undertaken at the Sorby Laboratory, Leeds), deep sea cores and outcrops.
Sediment dispersal in ancient depositional systems: an integrated multi-proxy provenance approach.
Supervisors: Prof. J. Stephen Daly, Dr Shane Tyrrell and Dr Peter D.W. Haughton
Contact: stephen.daly@ucd.ie
Project Description:
Provenance studies offer important insight into palaeogeography, ancient sediment pathways and drainage scales. The application of increasingly sophisticated microanalytical techniques has allowed for the rapid acquisition of provenance signals from individual mineral grains. However, the ability to reconstruct palaeodrainage models is hampered in a number of ways, e.g., in distinguishing between first cycle and reworked detritus. Furthermore, conventional techniques are unable to discriminate natural (lithology, weathering, erosion and transport) from user (sample selection) bias. These issues will be addressed with reference to large, well characterized depositional systems such as the Namurian of northern Britain using an integrated approach, including detailed petrography and in situ microanalysis of both labile (e.g., K-feldspar) and stable (e.g., zircon) detrital minerals.
The Neoproterozoic record on the Baltic Craton.
Supervisors: Prof. J. Stephen Daly and Dr Shane Tyrrell
Contact: stephen.daly@ucd.ie
Project Description:
The ancient continent of Baltica plays a pivotal role in past continental reconstructions. However for much of Earth history, the geological record is held in allochthonous rocks that have suffered significant (and often unquantifiable) tectonic displacement. This project will focus on the Mesoproterozoic and Neoproterozoic rock record on the autochthonous Baltic Shield especially on unmetamorphosed Mesoproterozoic sedimentary sequences and intrusive rocks. The project will entail fieldwork in the Kola Peninsula, Russia and adjacent parts of Finland and Norway. Isotopic analyses will be carried out on magmatic rocks to determine the timing of extension and on detrital minerals to constrain the maximum age of deposition and the sedimentary provenance. Palaeomagnetic analysis will be undertaken on dated magmatic and sedimentary rocks.
Petrogenesis and geodynamic significance of lamprophyres.
Supervisor: Prof. J. Stephen Daly
Contact: stephen.daly@ucd.ie
Project Description:
Lamprophyres are a minor but remarkably widespread component of the Caledonian orogenic belt in Ireland and Britain. This project will investigate the petrogenesis of this enigmatic group of rocks using intra-grain mineral geochemistry, isotope geochemistry and geochronology. Particular attention will be paid to discriminating between mantle and crustal contributions to the magma and possible links between the lamprophyres and calc-alkaline granites. Comparative studies will be carried out on lamprophyres and related rocks in younger orogenic belts with clear tectonic and geodynamic controls.
The metamorphic aureole of the Corvock Granite, Co Mayo.
Supervisor: Prof. J. Stephen Daly
Contact: stephen.daly@ucd.ie
Project Description:
This project will investigate the metamorphic response to advective heating and the compositional controls on contact metamorphism and associated fluid-rock interaction in the well-exposed metasedimentary aureole of the late Caledonian Corvock Granite in western Ireland. This aureole combines diverse bulk compositions and appropriate country rock geometry to allow the thermal and compositional controls on the metamorphic mineralogy to be separately assessed. In addition to geochemistry and petrology, isotopic dating of accessory minerals will be carried out to assess the duration of heating and to distinguish between different intrusive events as the main heat source.
Geological significance and mining-related problems of Navan framboidal ore.
Supervisors: Dr Julian Menuge, Dr John Ashton (Boliden Tara Mines) and Dr Adrian Boyce (Scottish Universities Environmental Research Centre, East Kilbride, Scotland)
Contact: j.f.menuge@ucd.ie
Project Description:
The main ore body of the world class carbonate-hosted Navan Zn-Pb deposit is capped by a debris flow called the Boulder Conglomerate that is partly economically mineralized as Conglomerate Group Ore (CGO). The CGO includes finely-laminated Zn-Pb ore rich is framboidal pyrite, thought to have formed on or near the sea floor through the action of sulphur reducing bacteria. This framboidal material oxidizes dangerously fast when mined and reduces Pb recovery during froth flotation. This project aims to answer two distinct sets of questions:
* Under what environmental conditions did framboidal ore form and how does this ore relate to the main Navan ore body beneath the Boulder Conglomerate?
* Why is framboidal ore subject to rapid oxidative heating during mining and why does its presence reduce Pb recovery during froth flotation?
To answer these questions a detailed textural, chemical and isotopic study of the framboidal ore will be carried out. Techniques will include optical and electron microscopy (including EDS and EBSD), laser ablation MC-ICPMS (Zn, Fe, Pb isotopes) and S isotope analysis.
Radiogenic isotopes in authigenic phases as tracers of past ocean circulation in the North Atlantic.
Supervisors: Prof. P. Frank McDermott, Dr Peter D.W. Haughton
Contact: frank.mcdermott@ucd.ie
Project Description:
This project will investigate the use of neodymium (Nd) isotope ratios in authigenic minerals (Fe-Mn hydroxides) and biological precipitates (nannofossil ooze and foraminifera) from selected North Atlantic sediment gravity cores to reconstruct variations in the Atlantic Meridional Overturning Circulation (MOC) in the late Quaternary. The project builds on the recently established regional chrono-stratigraphic framework for the late Quaternary sedimentary succession of the Rockall and Porcupine Bank areas. The focus will be on comparing authigenic (water-mass) Nd isotope signals with conventional proxies for water-mass changes that are based on nutrient cycling (e.g. foraminifera ?13C) to assess the integrity of authigenic Nd isotope signals. Initial research targets are the authigenic mineral coatings on detrital grains associated with Heinrich events that are well represented in the 70 gravity cores available to us from the outer part of the Porcupine Bank on the eastern flank of the Rockall Trough. Ultimately, the goal is to improve our understanding of the long-term stability and circulation modes of the Atlantic MOC, a fundamental requirement to build reliable models for the response of the MOC to warmer climates.
Reconstruction of Holocene climate variability in the Balkans using Speleothems.
Supervisor: Prof. P. Frank McDermott
Contact: frank.mcdermott@ucd.ie
Project Description:
The proposed research will focus on late Quaternary climate change along a NE-SW transect extending from coastal Croatia into central Bosnia. This region is critically important in the context of ongoing palaeoclimate research around the Mediterranean Basin, and has been identified in modelling studies as a 'climate change hot-spot', with the potential to provide a link between the western and eastern Mediterranean Basins. The region contains extensive cave systems, many of which are well decorated with speleothems (e.g. stalagmites and flowstones). Spelothems are now recognized as valuable high-resolution multi-proxy recorders of continental palaeoclimate and are near-ideal materials for U-series dating, using the 'daughter deficiency' 230Th/U method. In collaboration with colleagues in the Universities of Zadar (Croatia) and Sarajevo (Bosnia), the proposed research will involve fieldwork in both countries, and will utilize the climate record preserved in the selected speleothems to quantify changes in effective precipitation on a range of timescales in the late Quaternary. The new data will provide important new insights into the extent to which climatic conditions in the region varied, to test climate models and to provide a better framework to assess the likely impact of future climate change on rainfall in the region.
Rugose coral biostromes in Upper Viséan rocks, Co Sligo: taxonomic composition and palaeoecological associations.
Supervisor: Dr Ian D. Somerville
Contact: ian.somerville@ucd.ie
Project Description:
The Lower Carboniferous (Mississippian) limestones of NW Ireland are well exposed in coastal sections and provide excellent opportunities to examine Upper Viséan coral faunas on extensive bedding planes. This project will focus primarily on the colonial rugosans, but will examine also their association with solitary forms. Detailed investigations will be made on the diversity and abundance of corals and their relationship to facies. The taxonomic composition and construction of biostromes will be investigated and palaeoecological affinities established. Comparisons will be made with other Upper Viséan biostromes in Ireland and elsewhere in Europe within the Western Palaeotethys realm.
Research in Palaeobiology.
Supervisor: Dr Patrick J. Orr
Contact: patrick.orr@ucd.ie
Project Description:
In addition to the specific PhD projects listed above the Palaeobiology Research Group invites enquiries about possible research projects. The group's main research interests are in the areas of vertebrate and invertebrate taphonomy, including exceptionally preserved fossil faunas, and palaeoecological studies using trace fossils and ichnofabrics. Potential postgraduate students are invited to discuss these or related research topics with us.
UCD is an equal opportunities' employer
School of Geological Sciences Dublin Ireland; PhD Research Opportunities 2009
