Hidden depths: deformation and seismic hazard in continental collision zones

(ANDERSON_P23ARIES)

Hidden depths: deformation and seismic hazard in continental collision zones

(ANDERSON_P23ARIES)

Project Description

Supervisors

Professor Mark Anderson (University of Plymouth, SoGEES) – Contact me

Professor Luca Menegon, Department of Geosciences, University of Oslo

Dr Nick Roberts, British Geological Survey

Professor Jamie Wilkinson, Natural History Museum

 

Project Background

How does the base of a mountain belt deform and localize large earthquakes? Does it represent a preferential conduit for fluid flow in the Earth’s crust? This PhD project will address these questions using a continuous 2.4km section of core drilled through the base (décollement) of the Caledonian mountain belt as part of the International Continental Drilling Programme project “Collisional Orogeny in the Scandinavian Caledonides” (COSC-2) [1]. The core represents a unique opportunity to examine the role of fluids in facilitating deformation in the lower plate during continental collision [2], sections of the continental crust that are inaccessible in areas of active continental collision because they are deeply buried. The results will be used to critically re-evaluate mechanical models for lower plate deformation in active mountain belts and implications for better modelling of seismic hazard in these settings [3].

Research methodology

Mineral veins represent proxies for fluid flow during deformation. Microstructural and petrographic analyses of vein samples and associated alteration will determine the spatial distribution, relative timing and mechanism of vein forming processes throughout the core-section. U-Pb geochronology (using laser ablation inductively coupled plasma mass spectrometry) and fluid inclusion studies will constrain the vein chronology and the pressure, temperature and composition (including isotopic composition) of vein-forming fluids [4]. Together the data will be used to evaluate the role of fluids in relation to slip on thrust faults within both ancient and modern décollements.

Training

The successful candidate will be part of a large international collaborative research team working under the wider remit of COSC-2. Training will be given in structural analysis of drill core (using state-of-the art logging tools), electron microscopy/microprobe analysis, electron backscatter diffraction, U-Pb geochronology and fluid inclusion analysis. The student will develop expertise in each method and their application to understanding how geological fluids influence deformation. Training will also be given in communication of research results and how these can be integrated with geophysical models for seismicity in active collisional settings [5].

Person specification

Candidates should have a degree in Earth Sciences/Geology or similar. Desirable experience includes structural geology, geochemistry, plate tectonics and natural hazards.

References

  • [1] Lorenz H., Rosberg J-E., Juhlin C., Klonowska I., Lescoutre R., Westmeijer G., Almqvist B.S.G., Anderson M., Bertilsson S., Dopson M., Kallmeyer J., Kück J., Lehnert O., Menegon L., Pascal C., Rejkjær S.& Roberts N.M.W. 2022. COSC-2 - Drilling the basal decollement and underlying margin of palaeocontinent Baltica in the Paleozoic Caledonide Orogen of Scandinavia. Scientific Drilling, 30, 43-57. https://doi.org/10.5194/sd-30-43-2022
  • [2] Prando F., Menegon L., Anderson M., Marchesini B., Mattila J. & Viola G. 2020. Fluid-mediated, brittle–ductile deformation at seismogenic depth – Part 2: Stress history and fluid pressure variations in a shear zone in a nuclear waste repository (Olkiluoto Island, Finland). Solid Earth, 11, (2) 489-511. https://doi.org/10.5194/sd-30-43-2022
  • [3] Zhao Y., Grujic D., Baruah S., Drukpa D., Elkadi J., Hetényi G., King G.E., Mildon Z.K., Nepal N. & Welte C. 2021. 'Paleoseismological Findings at a New Trench Indicate the 1714 M8.1 Earthquake Ruptured the Main Frontal Thrust Over all the Bhutan Himalaya. Frontiers in Earth Science 9
  • [4] Roberts N.M.W. and Holdsworth R.E. 2022. Timescales of faulting through calcite geochronology: A review. Journal of Structural Geology, 158, p.104578. https://doi.org/10.1016/j.jsg.2022.104578
  • [5] Bilham R. 2019. Himalayan earthquakes: a review of historical seismicity and early 21st century slip potential. In: TRELOAR, P. J. & SEARLE, M. P. (eds) 2019. Himalayan Tectonics: A Modern Synthesis. Geological Society, London, Special Publications, 483, 423–482.

Key Information

  • This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1st October 2023. The closing date for applications is 23:59 on 11th January 2023.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship, which covers fees, stipend (£17,668 p.a. for 2022/23) and research funding. International applicants are eligible for fully-funded ARIES studentships including fees. Please note however that ARIES funding does not cover additional costs associated with relocation to, and living in, the UK.
  • ARIES students benefit from bespoke graduate training and ARIES provides £2,500 to every student for access to external training, travel and conferences, on top of all Research Costs associated with the project. Excellent applicants from quantitative disciplines with limited experience in environmental sciences may be considered for an additional 3-month stipend to take advanced-level courses.
  • ARIES is committed to equality, diversity, widening participation and inclusion in all areas of its operation. We encourage enquiries and applications from all sections of the community regardless of gender, ethnicity, disability, age, sexual orientation and transgender status. Academic qualifications are considered alongside non-academic experience, and our recruitment process considers potential with the same weighting as past experience.
  • All ARIES studentships may be undertaken on a part-time or full-time basis, visa requirements notwithstanding
  • For further information, please contact the supervisor. To apply for this Studentship follow the instructions at the bottom of the page or click the 'apply now' link.
  • ARIES is required by our funders to collect Equality and Diversity Information from all of our applicants. The information you provide will be used solely for monitoring and statistical purposes; it will remain confidential, and will be stored on the UEA sharepoint server. Data will not be shared with those involved in making decisions on the award of Studentships, and will have no influence on the success of your application. It will only be shared outside of this group in an anonymised and aggregated form. You will be ask to complete the form by the University to which you apply.

Applications are open

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