Using novel techniques to investigate foraminifera biomineralisation and geochemistry

Applications are invited for a 3.5 years PhD studentship. The studentship will start on 01 October 2025

Apply 

To apply for the ARIES Doctoral Training Partnership studentship please simply click on the ‘online application’ link below for PhD Marine Sciences  
Online application
Within the Research section of the application form, in the following fields, please add: 
  • Proposed project title/studentship title: add Using novel techniques to investigate foraminifera biomineralisation and geochemistry 
  • Proposed supervisor: add Dr Tracy Aze 
  • Studentship Code: add ARIES 25-10 Aze
When the application asks for a research proposal, please just upload a blank document. A research proposal is not needed for this programme as you are applying directly to a studentship project. 

Application guidance 

It is important that you follow the instructions above or your application for this studentship may be missed and therefore will not be considered. 
Before applying, please ensure you have read the Doctoral College’s general information on applying for a postgraduate research degree.  
For more information on the admissions process please contact research.degree.admissions@plymouth.ac.uk. 
Director of Studies: Dr Tracy Aze  
2nd Supervisor: Dr Christopher Smart  
Applications are invited for a 3.5 years PhD studentship. The studentship will start on 1 October 2025 

Project description 

Planktonic foraminifera are single-celled marine protists that build calcium carbonate (calcite) shells, which are well-preserved in deep sea sediments. They have existed for ~150 million years, are found in all global oceans, and have one of the best species-level fossil records. Consequently, they are widely employed for palaeoenvironmental and biostratigraphic research and are increasingly becoming a model for macroevolutionary analysis.
Despite decades of research, the mechanisms by which planktonic foraminifera build their calcite shells remain elusive. This project will utilise Electron Back Scatter Diffraction (EBSD) and in-situ chemical analyses to investigate the shell wall at the microstructural level. The aim is to better understand how foraminifera biomineralisation occurs and how these structures vary between species. This research will not only enhance understanding of biomineralisation but also provide insights into how these processes have evolved. By linking microstructural features to environmental conditions and evolutionary history, it could improve palaeoenvironmental reconstructions and our understanding of macroevolutionary trends.

Research methodology  

  1. Investigate microstructural differences in the biomineralisation processes of planktonic foraminifera with differing wall textures.  
  2. Quantify changes in the microstructure of planktonic foraminifera with differing preservation histories and investigate the implications for alteration of trace metal geochemistry.  
  3. Investigate the prevalence of calcite twinning throughout the evolutionary history of planktonic foraminifera and the implications for shell strength.  

Training  

The student will become an expert in foraminifera taxonomy and ecology and gain experience in various analytical techniques, such as Light Microscopy Z-stack image capture, Electron Back Scatter Diffraction, Time-of-flight Mass Spectrometry, Scanning Electron Microscopy, Fore Scatter Microscopy, and Electron Microprobe Analysis of trace element geochemistry.
Fig. 1 a) A scanning electron microscope (SEM) image of the planktonic foraminifera Globigernoides ruber  
b) An SEM image of the cross-section of the shell of G. ruber  
c) An EBSD map of the cross-section of the calcite shell of G. ruber showing the orientation of calcite mesocrystals (individually coloured units)  
d) An Electron Microprobe Analysis (EMPA) of trace element geochemistry map of the cross-section of the calcite shell of G. ruber showing alternate colours representing banding of high and low magnesium calcite typically associated with primary biomineralisation.    
Examples of A scanning electron microscope (SEM) and Electron Microprobe Analysis (EMPA)
Fig.1 

References 

Procter, F. A., Piazolo, S., John, E. H., Walshaw, R., Pearson, P. N., Lear, C. H., and Aze, T. (2024) Electron backscatter diffraction analysis unveils foraminiferal calcite microstructure and processes of diagenetic alteration, Biogeosciences, 21, 1213–1233, https://doi.org/10.5194/bg-21-1213-2024. 
Arns, A. I., Evans, D., Schiebel, R., Fink, L., Mezger, M., Alig, E., et al. (2022). Mesocrystalline architecture in hyaline foraminifer shells indicates a non-classical crystallisation pathway. Geochemistry, Geophysics, Geosystems, 23, e2022GC010445. https://doi.org/10.1029/2022GC010445
John, E. H., Staudigel, P. T., Buse, B., Lear, C. H., Pearson, P. N., & Slater, S. M. (2023). Revealing their true stripes: Mg/Ca banding in the Paleogene planktonic foraminifera genus Morozovella and implications for paleothermometry. Paleoceanography and Paleoclimatology, 38, e2023PA004652. https://doi.org/10.1029/2023PA004652  
de Nooijer, L. J., Spero, H. J., Erez, J., Bijma, J., and Reichart, G. J.: Biomineralization in perforate foraminifera, Earth-Sci. Rev., 135, 48–58, https://doi.org/10.1016/j.earscirev.2014.03.013, 2014. 
Yin, X., Griesshaber, E., Checa, A., Nindiyasari-Behal, F., Sánchez-Almazo, I., Ziegler, A., and Schmahl, W. W.: Calcite crystal orientation patterns in the bilayers of laminated shells of benthic rotaliid foraminifera, J. Struct. Biol., 213, 107707, https://doi.org/10.1016/j.jsb.2021.107707, 2021. 

Eligibility 

Applicants should have a first or upper second class honours degree in Earth, Environmental, or Biological Science or a relevant Masters qualification.
If your first language is not English, you will need to meet the minimum English requirements for the programme, IELTS Academic score of 6.5 (with no less than 5.5 in each component test area) or equivalent.
ARIES is currently awaiting confirmation of funding under the BBSRC-NERC DLA award scheme, which is expected shortly. Funding for this studentship is subject to this confirmation. 
Successful candidates who meet UKRI’s eligibility criteria will be awarded a fully-funded ARIES studentship of fees, maintenance stipend (£19,237 p.a. for 2024/25) and research costs. 
A limited number of ARIES studentships are available to International applicants. Please note however that ARIES funding does not cover additional costs associated with relocation to, and living in, the UK. 
NB: The studentship is supported for 3.5 years of the four-year registration period. The subsequent 6 months of registration is a self-funded ‘writing-up’ period. 
ARIES is committed to equality, diversity, widening participation and inclusion in all areas of its operation. We encourage applications from all sections of the community regardless of gender, ethnicity, disability, age, sexual orientation, and transgender status. Projects have been developed with consideration of a safe, inclusive, and appropriate research and fieldwork environment. Academic qualifications are considered alongside non-academic experience, with equal weighting given to experience and potential. 
For further information, please visit www.aries-dtp.ac.uk.
If you wish to discuss this project further informally, please contact Dr Tracy Aze .
Please see our apply for a postgraduate research programme page for a list of supporting documents to upload with your application. 
For more information on the admissions process generally, please visit our Apply for a postgraduate research programme page or contact the Doctoral College .
The closing date for applications on 8 January 2025. 
Shortlisted candidates will be invited for interview after the deadline. We regret that we may not be able to respond to all applications. Applicants who have not received a response within six weeks of the closing date should consider their application has been unsuccessful on this occasion.