The Formation and Evolution of Continental Rift Flank Topography and Adjacent Basins: Analysis of the Rukwa-Malawi Sector of the East African Rift

School of Geographical and Earth Sciences
3rd Supervisor - Professor Fin Stuart ([Email Address Removed])

The process of continental rifting is integral to the theory of plate tectonics and the long-term evolution and erosion of rift flank topography, in particular, is crucial to understanding the evolution of all offshore passive margin sedimentary basin environments. A robust chronology of key stages of continental rifting is central to understanding the geodynamic process of rifting itself and how it relates to regional dynamic uplift, and its consequences for sedimentary flux to the basin, because it is the chronology that defines the key temporal framework for resolving between cause and effect. The East African Rift system (EARS) is widely regarded as the type example of an active continental rift zone, and has been extensively studied and much of our understanding of the role that rifting plays in plate tectonic theory has come from observations made in the EARS. Exciting progress has been made in developing numerical models of extensional processes, magma intrusion, and particularly the pattern of rift flank uplift (e.g. Koptev et al., 2015), but a paucity of high quality, quantitative data on timing of key events able to constrain and verify these models remains.

Resolving outstanding questions about the relative timing between regional uplift, magmatism and the onset of rifting itself are key to making further progress (e.g. Toomey, 2012). In this project we will use low temperature thermochronometry (apatite fission track and (U-Th)/He analysis) to derive robust thermal histories for basement rocks and these in turn will provide robust, quantitative constraints on likely uplift and exhumation histories for the evolving rift margin topography. The Rukwa-Malawi rift sector is located centrally within the western branch of the EARS and within the broad zone of predicted dynamically supported topography and so is ideally cited for this study in a regional context. The local scale tectonic architecture, structure of faults and the geology of the basins are also all extremely well documented by a wealth of geophysical and field based geological observations, and in particular the exceptional characterisation and dating of the basin fill stratigraphy (e.g. Roberts et al., 2012). These new data will be used to constrain and test sophisticated thermo-mechanical numerical models of rift evolution to gain a fuller understanding of how these features evolve and what mechanisms control their evolution.

Importantly, field access, logistics and specific field knowledge of the key type sections and the region are all available from our own and our partners expertise, including industry partners who are actively drilling in the Kyela basin. Training will include direct interaction with industry sponsors and tailored post graduate level courses designed to maximize employment opportunities within industry or academic research.

Koptev, A., Calais, E., Burov, E., Leroy, S., & Gerya, T. (2015). Dual continental rift systems generated by plume-lithosphere interaction. Nature Geoscience, v. 8, p. 388–392, doi:10.1038/ngeo2401
Roberts, E. M. et al. 2012. Initiation of the western branch of the East African Rift coeval with the eastern branch. Nature Geoscience, 5(4), 289-294.
Toomey, D. R. 2012. Plate tectonics: Piecing together rifts. Nature Geoscience, 5(4), 235-236.

How to Apply: Please refer to the following website for details on how to apply:
http://www.gla.ac.uk/research/opportunities/howtoapplyforaresearchdegree/