The formation of Earth’s continents during the Archean eon is one of the major transformation that our planet has experienced throughout its history. Continent formation had a profound effect on the composition of the Earth’s surface by kick-starting the release of elements necessary for the development of life in the oceans, but also on the Earth’s mantle by generating its compositional heterogeneity. However, despite the crucial role of continent landmasses in Earth’s evolution, the processes and geodynamic context in which they were formed and how these evolved during the Archean still remain hotly debated. In this PhD project, the student will use cutting edge petrology combined with a set of novel, purpose-designed isotopic tools to test different models of continent formation.
Project Aims and Methods
To do this, the student will carry out fieldwork to collect granitoid samples representative of the juvenile crust from the Pilbara and Yilgarn cratons (Western Australia, 3.5–2.6 Ga). This sample set will complement an already collected set of samples from the Kaapvaal craton (3.6-2.6 Ga).
The student will combine cutting-edge petrological studies of Archean granitoids with high-precision radiogenic (Sr-Nd-Pb) and heavy stable isotope (Ti, Mg, Si,…) measurements to investigate a range of questions related to the formation of these magmas. After initial sample characterisation carried out at case partner the Geological Survey of Western Australia (GSWA), all isotope work will be carried out in the newly set up state-of-the-art isotope geochemistry laboratory at Cardiff University.
The combined dataset will allow the student to attain the following research objectives:
1. Trace the mantle sources of Archean granitoids throughout the lifetime of Archean cratons
2. Determine which processes govern the formation and evolution of Archean granitoids
3. Evaluate if and how these evolved during the Archean.
Overall, this project will allow for a much clearer understanding of the processes and geological context of continent formation in the Archean.
The project will suit a candidate interested in Earth Sciences, magmatic processes, isotope geochemistry and fieldwork.
CASE or Collaborative Partner
GSWA (Case partner) hosts a number of researchers experts in Archean geology. They will provide invaluable expertise on the geology of the Pilbara and Yilgarn cratons, selection of sampling targets as well as data interpretation.
The student will receive extensive training in isotope geochemistry, petrology, fieldwork as well as numerical modelling by all supervisors. In addition, the student will be trained in cutting-edge analytical techniques in the newly installed geochemistry analytical facilities at Cardiff University.
In addition to project-specific training, the student will have access to the DTP training courses, as well as a range of Cardiff University Student Development courses, to maximise transferable skills. The student is also expected to present project results to national and international conferences. Finally, the student will have the opportunity to demonstrate both in the classroom and in the field.
Combined, the training package of the project will give the student an excellent basis for the rest of their career.
How to apply:
You should apply to the Doctor of Philosophy in Earth and Ocean Sciences with a start date of October 2020, including:
an upload of your CV
a personal statement/covering letter
two references (applicants are recommended to have a third academic referee, if the two academic referees are within the same department/school)
current academic transcripts.
In the research proposal section of your application, please specify the project title and supervisors of this project and copy the project description in the text box provided. In the funding section, please select ’I will be applying for a scholarship/grant’ and specify that you are applying for advertised funding from NERC GW4+ DTP.
If you wish to apply for more than one project please email [email protected]
The deadline for applications is 16:00 on 6 January 2020.
Shortlisting for interview will be conducted by 31 January 2020.
Shortlisted candidates will then be invited to an institutional interview. Interviews will be held in Cardiff University between 10 February and 21 February 2020
Dhuime, B., Wuestefeld, A., Hawkesworth, C.J., 2015. Emergence of modern continental crust about 3 billion years ago. Nat. Geosci. 8, 552–555. https://doi.org/10.1038/ngeo2466
Johnson, T.E., Brown, M., Gardiner, N.J., Kirkland, C.L., Smithies, R.H., 2017. Earth’s first stable continents did not form by subduction. Nature 543, 239–242. https://doi.org/10.1038/nature21383
Nebel, O., Capitanio, F.A., Moyen, J.-F., Weinberg, R.F., Clos, F., Nebel-Jacobsen, Y.J., Cawood, P.A., 2018. When crust comes of age: on the chemical evolution of Archaean, felsic continental crust by crustal drip tectonics. Phil Trans R Soc A 376, 20180103. https://doi.org/10.1098/rsta.2018.0103
Smithies, R.H., Van Kranendonk, M.J., Champion, D.C., 2005. It started with a plume – early Archaean basaltic proto-continental crust. Earth Planet. Sci. Lett. 238, 284–297. https://doi.org/10.1016/j.epsl.2005.07.023