My research interests cover both my PhD research and work undergone during my fourth year at Cambridge, where I studied Earth Sciences as part of Natural Sciences. I primarily focus on the geochemical analysis of erupted material at volcanic settings to gain a better understanding of the physical and chemical properties of the underlying mantle, with emphasis on Ethiopia for my PhD.
I am funded by the Leeds-York NERC DTP (2018), and am supervised by David Ferguson and Dan Morgan here in Leeds, Gezahegn Yirgu of the University of Addis Ababa, and Marie Edmonds of the Department of Earth Sciences, University of Cambridge.
Explosive basaltic volcanism in the Ethiopian Rift
The East African Rift is formed through the continental rifting of the Nubian and Somalian subplates of Africa. The Ethiopian sector of the Rift is one of the most volcanically active regions on Earth, and provides a natural laboratory to study the interplay between magmatism and rift zone tectonics. Magmas, generated at depth beneath the rift, erupt at the surface harbouring geochemical clues as to the properties of the underlying melting mantle, and the flux of volatile components into the Earth's exogenic system (e.g. water, carbon dioxide, and halogens). Likewise, transport between different magma chambers near the surface generates chemical disequilibrium between crystals and their carrier magma, resulting in geochemical diffusion across crystals as they grow and equilibrate with the surrounding melt. In addition, questions still remain as to whether a hot mantle plume continues to drive volcanism in Ethiopia. For my PhD I will analyse olivine crystals collected from Ethiopian Rift cinder cones to build a picture of magmatic generation and transport resulting from continental rifting. This will permit new insight into magmatic processes occurring within actively rifting environments, and provide constraints on carbon degassing resulting from Ethiopian volcanism.
Volcanic carbon fluxes through geological time
Volcanic eruptions release a vast amount of carbon to the surface in the form of CO2; volcanoes at tectonic settings (e.g. continental rifts, volcanic arcs) therefore are a primary control on carbon outgassing from the deep Earth. This carbon is then returned to the deep Earth through subduction of carbon-bearing phases in the crust and lithospheric mantle. Attempts at constraining carbon fluxes at tectonically-driven volcanic settings (rifts and subduction zones) have primarily focused on present day values (e.g. Kelemen and Manning, 2015, PNAS). The variation in plate boundary lengths through time is likely to cause variations in carbon entering the deep Earth at subduction zones and leaving it through volcanism. Through models of tectonic parameters generated through GPlates software and present-day observations made at volcanic settings and subduction zones, I intend to quantify fluxes of carbon ingassing and outgassing out of the mantle, and estimate uncertainty in those estimates. This work is in collaboration with the Deep Carbon Observatory.
Collaborators: Emily Mason, Sascha Brune, Marie Edmonds, Sabin Zahirovic
Relating olivine crystallisation temperature to mantle temperature
The temperature of the mantle is a primary control on the extent of melting it undergoes during upwelling, and is therefore a necessary property to quantify when modelling large-scale mantle convection. Mantle temperature can also provide clues into the properties of the melting mantle lithology. The geochemistry of olivine crystals erupted at anhydrous basaltic settings can be related to the temperature at which they crystallised, which in turn can be correlated to the temperature of the mantle. By taking a Bayesian approach to relate observed geochemistry and geophysics to processes at depth, I intend to assess whether crystallisation temperatures of olivine crystals can be used to infer mantle temperatures at different settings. This work is a continuation of my Masters project completed in 2018; title: New constraints on the temperature of the Hawaiian mantle.
Collaborators: Simon Matthews, Oliver Shorttle, Marie Edmonds, John Maclennan
- MSci, (Earth Sciences; Natural Sciences), Corpus Christi College, University of Cambridge
- BA (Hons), Natural Sciences, Corpus Christi College, University of Cambridge
Research groups and institutes
- Rocks, Melts and Fluids
- Institute of Geophysics and Tectonics