Keele Petrology Group
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Current PhD Projects
Xenoliths as tracers of magmatic and intra-crustal processes at subduction zone volcanoes
Supervisors : Dr Ralf Halama and Dr Ralf Gertisser
Transitions in eruption styles of arc eruptions
Supervisor : Dr Ralf Gertisser and Dr Ralf Halama
Completed PhD Projects
Luke Hepworth - Linking in situ crystallisation and magma replenishment in the Rum layered Intrusion, NW Scotland
Linking in situ crystallisation and magma replenishment in the Rum layered Intrusion, NW Scotland
Adam Jeffery - Petrogenesis and contrasting eruption styles of peralkaline silicic magmas from Terceira and São Miguel, Azores
Petrogenesis and contrasting eruption styles of peralkaline silicic magmas from Terceira and São Miguel, Azores
Supervisors : Dr Ralf Gertisser, Dr Brian O'Driscoll
Liam Bullock - Structure, emplacement and textural evolution of young obsidian lavas in the Aeolian islands, Italy
Structure, emplacement and textural evolution of young obsidian lavas in the Aeolian islands, Italy
Supervisors : Dr Ralf Gertisser, Dr Brian O'Driscoll
The emplacement kinematics of silicic lava flows are not well understood, due to a paucity of observations on active flows. The measurement of textural and structural features can serve as an important tracer for silicic lava flow emplacement and deformation.
Silicic volcanism defines recent volcanic activity at the Aeolian Archipelago, Italy. The Rocche Rosse obsidian lava flow represents the youngest outpourings of the Monte Pilato pumice cone on the northern coast of Lipari (Aeolian Islands, Italy).
In my study, structural measurements on surface features and quantitative textural data are coupled with detailed mapping and cross sectional interpretations of the Rocche Rosse obsidian to gain insight into its rheological behaviour and emplacement history.
This will be achieved through meeting the following objectives:
- Undertake detailed structural investigations of the emplacement mechanisms and post-emplacement deformation of the Rocche Rosse obsidian lava flow on the island of Lipari and the Pietre Cotte lava flow on Vulcano.
- Full textural and compositional characterisation of spherulite populations in young silicic lava bodies in the Aeolian Islands to identify spherulite heterogeneity and crystallization conditions.
- Examination and a detailed evaluation of the relationship between spherulite occurrence and flow emplacement and deformation.
Meeting these objectives centres on careful and detailed studies of two main study areas – the Rocche Rosse obsidian lava flow (Lipari) and the Pietre Cotte obsidian lava flow (Vulcano), as well as selected young silicic lava bodies across Lipari and Vulcano that exhibit spherulitic textures. The methodologies to address the structural investigations include detailed mapping, and cross section and high resolution satellite imagery interpretations of the Rocche Rosse and Pietre Cotte obsidian lava flows. In order to address the textural characterisation of spherulites, strain analysis, textural observations, crystal-size distribution (CSD), microprobe and Raman spectroscopy methods will be applied in order to create an extensive dataset of individual spherulitic populations.
The detailed textural and structural features documented provide important constraints on the rheological properties of historic obsidian lava flows in the Aeolian Islands, important for understanding the structural kinematics and emplacement mechanisms of young silicic lava flows.
Lizzie Derbyshire - Upper mantle processes, serpentinisation and late-stage alteration preserved in British ophiolites
Upper mantle processes, serpentinisation and late-stage alteration preserved in British ophiolite peridotites and chromitites
Supervisors : Dr Brian O'Driscoll, Dr Ralf Gertisser
In ophiolitic mantle, the robust Cr-spinel crystals in chromitite seams are the only primary mineral which remains relatively unaltered, retaining primary igneous compositions even after extensive serpentinisation alteration. Therefore, the chemical compositions recorded by chromitite are considered to retain primary melt compositions and partial melting extent. Serpentinisation effects are recorded at Cr-spinel crystal edges and along crystal fractures as a Fe-rich (ferritchromit) alteration rims.
Chromitite seam in dunite from Shetland Ophiolite, Unst
The Shetland Ophiolite (Isle of Unst, Shetland) and Ballantrae Ophiolite (Ayrshire) are the focus of this study to understand chromitite formation and the serpentinisation process, in addition to explaining the complex melt-rock and melt-melt interactions in the upper mantle. The spectacular Shetland and Ballantrae Ophiolites preserve podiform chromitite seams which are currently being investigated by petrographic, mineral chemical and crystal structural analysis.
Katie Preece - Transitions between effusive and explosive activity at Merapi volcano, Indonesia
Transitions between effusive and explosive activity at Merapi volcano, Indonesia: a volcanological and petrological study of the 2006 and 2010 eruptions.
(University East Anglia; co-supervised by Ralf Gertisser)
Sylvain Charbonnier - The dynamics and hazards of small-volume pyroclastic flows
The dynamics and hazards of small-volume pyroclastic flows: a case study of the 2006 eruption of Merapi volcano, Java, Indonesia
Supervisor : Dr Ralf Gertisser