An innovative isotopic approach to investigating the pre-Cambrian carbon cycle

(DICKSON_RH24ARIES)

An innovative isotopic approach to investigating the pre-Cambrian carbon cycle

(DICKSON_RH24ARIES)

Project Description

Supervisors

Professor Alex Dickson, Royal Holloway University of London – Contact me

Dr Hannah  Elms, Royal Holloway University of London

Professor Simon Poulton, University of Leeds

Scientific background

The burial of organic matter in the ocean is a major component of the global carbon cycle, which impacts on global climate. The isotopic composition of the trace element cadmium may be capable of recording variations in marine organic matter burial in the past. However, it is unclear how accurately this new geochemical proxy may record carbon cycle variations in the pre-Cambrian world, when ocean chemistry was rather different to the present day. In this PhD project you will assess the ability of cadmium isotopes to trace organic carbon burial in the late Paleoproterozoic to early Neoproterozoic using a suite of samples ranging from 1.8–0.8 billion years old. You will use your observations to understand the operation of the cadmium cycle in the Proterozoic, and to test important hypotheses on the history and evolution of Earth’s environmental and biotic systems.

Research methodology

You will trace the ancient cadmium cycle using the isotopic composition of cadmium in marine sediments and minerals. Much of the sample material available for the project is already held by the supervisory team but there may be opportunities to participate in fieldwork to collect fresh samples. You will generate Cd isotope data using ultra-clean laboratory facilities and multi-collector mass spectrometry and complement these data with trace element and mineralogical data to interpret ancient depositional conditions, and hence, infer ancient ocean chemistry. The project has the potential for a significant modelling component, which would involve the use of Python and/or Matlab.

Training

You will receive training in sediment sampling, the preparation of isotopic samples in ultra-clean laboratory conditions, the measurement of isotope samples using Multi-Collector Inductively Coupled Mass Spectrometry (MC-ICP-MS), as well as data processing and modelling techniques. You will also benefit from the advanced research skills training courses offered by Royal Holloway. You will be embedded in the new Royal Holloway Centre of Climate, Ocean and Atmosphere with the chance to interact and learn from researchers studying in related fields.

Person specification

You should have a background in Earth Sciences, Geology, Physical Geography or Chemistry and be interested in isotope geochemistry and environmental change.

References

  • 1 Bryan, A.L., Dickson, A.J., Dowdall, F., Homoky, W., Porcelli, D. and Henderson, G.M. (2021), Controls on the cadmium isotope composition of modern marine sediments. Earth and Planetary Science Letters 565, 116946.
  • 2 Dickson, A.J., Idiz, E., Porcelli, D., Murphy, M., Celestino, R., Jenkyns, H.C., Poulton, S.W., Hesselbo, S.P., Hooker, J., Ruhl, M. and van den Boorn, S.H.J.M. (2022), No effect of thermal maturity on the Mo-, U-, Cd- and Zn-isotope compositions of lower Jurassic organic-rich sediments. Geology 50, 598–602.
  • 3 Dickson, A.J., Idiz, E., Porcelli, D., Murphy, M., Celestino, R., Jenkyns, H.C., Poulton, S.W., Hesselbo, S.P., Hooker, J., Ruhl, M. and van den Boorn, S.H.J.M. (2022), No effect of thermal maturity on the Mo-, U-, Cd- and Zn-isotope compositions of lower Jurassic organic-rich sediments. Geology 50, 598–602.
  • 4 Poulton, S.W., Fralick, P.W. and Canfield, D.E. (2004), The transition to a sulfidic ocean ~1.84 billion years ago. Nature 431, 173¬–177.
  • 5 Poulton, S.W., Fralick, P.W. and Canfield, D.E. (2010), Spatial variability in oceanic redox structure 1.8 billion years ago. Nature Geoscience 3, 486–490.

Key Information

  • This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1st October 2024. The closing date for applications is 23:59 on 10th January 2024.
  • Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship, which covers fees, stipend (£18,622 p.a. for 2023/24) 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. We expect to award between 4 and 6 studentships to international candidates in 2024.
  • 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.
  • ARIES funding is subject to UKRI terms and conditions. Postgraduate Researchers are expected to live within reasonable distance of their host organisation for the duration of their studentship. See https://www.ukri.org/publications/terms-and-conditions-for-training-funding/ for more information

Applications open

Click this link to apply to Royal Holloway, University of London