Building the oceans: the anatomy of magma flow in sheeted dykes at fast-spreading ridges

(MORRIS_P23ARIES)

Building the oceans: the anatomy of magma flow in sheeted dykes at fast-spreading ridges

(MORRIS_P23ARIES)

Project Description

Supervisors

Professor Antony Morris (University of Plymouth, School of Geography, Earth and Earth Sciences) – Contact me

Dr Michelle Harris, University of Plymouth, School of Geography, Earth and Earth Sciences

Dr Andrew Parsons, University of Plymouth, School of Geography, Earth and Earth Sciences

Prof Chris MacLeod, School of Earth and Environmental Sciences, Cardiff University

 

Project background

Fast-spreading rate ocean ridges are responsible for forming 50% of the world’s oceans, yet the magmatic processes involved in building the crust remain poorly understood. Transportation of melt at these ridges is typically considered as a 2D process, yet lateral variations in seafloor morphology and erupted lava compositions along ridge axes show that there must also be significant along-axis (3D) transport and evolution of melt during formation of the crust. This project aims to discover how this 3D magma transport system operates in upper crustal sheeted dyke complexes along fast-spreading ridges, using field and laboratory analyses of rocks exposed in the Oman ophiolite, a major slice of oceanic crust and mantle exposed on land, representing the only place in the world where this problem may be addressed.

Research methodology

The student will collect samples from sheeted dykes exposed along a >100 km fossil spreading ridge segment in Oman. In Plymouth, they will perform magnetic fabric analyses on these samples to detect imbrication of crystals along dyke margins, use these microfabrics to determine the 3D orientation of magma flow during dyke intrusion, and map out domains of different dyke emplacement directions along the ridge. They will also determine dyke geochemical compositions and relate these to flow regimes. Paleomagnetic analyses will allow the student to correct dyke orientations and flow directions for the effects of later tectonic rotations, thereby reconstructing the Oman spreading ridge system.

Training

The student will be trained in: (i) advanced geological fieldwork techniques (including field description and structural analysis of mafic rocks) during two field seasons in Oman; and (ii) a range of magnetic and geochemical techniques that also have wide applications outside of the specific topic of this project. The project links to a wider NERC-funded investigation of the 3D anatomy of magma transport along fast-spreading ridges, allowing the student to become skilled in collaborative research practices via membership of an interdisciplinary research team addressing a major topic in marine geoscience.

Person Specification

We seek an enthusiastic individual with an Earth Science-related degree, and a passion for fieldwork, geophysics, igneous petrology and structural geology.

References

  • Morris, A., Meyer, M., Anderson, M. W. and MacLeod, C. J., 2019. What do variable magnetic fabrics in gabbros of the Oman ophiolite reveal about lower crustal magmatism at fast spreading ridges? Geology, 47, 275-278, doi: 10.1130/G45442.1.
  • Morris, A., Meyer, M., Anderson, M. W. and MacLeod, C. J., 2016. Clockwise rotation of the entire Oman ophiolite occurred in a suprasubduction zone setting. Geology, 44, 1055-1058, doi: 10.1130/G38380.
  • Morris, A. and Maffione, M., 2016. Is the Troodos ophiolite (Cyprus) a complete, transform fault-bounded Neotethyan ridge segment? Geology, 44, 199-202, doi: 10.1130/G37529.1.
  • Kelemen, P. B., Matter, J. M., Teagle, D. A. H. Coggon, J. A., and the Oman Drilling Project Science Team (inc. Morris, A., Harris, M., and MacLeod, C. J.), 2020. Proceedings of the Oman Drilling Project: College Station, TX (International Ocean Discovery Program), doi: 10.14379/OmanDP.proc.2020.
  • Maffione, M., van Hinsbergen, D. J. J., de Gelder, G. I. N. O., van der Goes, C. and Morris, A., 2017. Kinematics of Late Cretaceous subduction initiation in the Neo-Tethys Ocean reconstructed from ophiolites of Turkey, Cyprus and Syria. Journal of Geophysical Research, 122, 3953-3976, doi: 10.1002/2016JB013821.

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.

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