Petrology: Igneous, Metamorphic and Volcanic Studies
Research Staff involved in this discipline:
Dr Judith Bunbury, Dr Hazel Chapman, Dr Jason Day, Dr Margaret Hartley, Dr Peter Leggo, Dr Olivier Namur, Dr Llewelln Pilbeam, Dr Stephen Reed, Oliver Shorttle
This grouping combines research into igneous, metamorphic and volcanic processes to enhance understanding of global tectonics as well as their more immediate impacts on our surficial environment. Our strategy is to integrate geological observational studies (field work, petrology, geochemical and isotopic analyses) with interdisciplinary work on multiphase flow in deformable media and the properties of the materials involved.
- The establishment of remote, high-resolution measurements of volcanic gasses in conjunction with analyses of melt inclusions to model the physical processes occurring during volcanic eruptions.
- Observations of rock textures are coupled with theoretical models and the results of laboratory experiments in order to answer a variety of problems associated with flow of reactive fluids in rocks and crystal mushes, and the evolution of solidifying igneous rocks. Current projects include textural studies of the Skaergaard and Rum Layered Intrusions, together with studies of crystal-rich nodules entrained in lava flows.
- We are developing, the fluid dynamical framework needed in the study of 'mushy' layers, which occur whenever a multi-component melt is cooled and solidifies, and of phenomena at basaltic volcanoes, such as lava lakes and fire fountains.
- Microanalytical techniques are used to study compositional variation within crystals and melt inclusions from basalts. These observations are used to study the origin of compositional heterogeneity in mantle melts and to track the mixing and crystallisation of these melts in convecting magma chambers.
- To understand melt generation processes associated with continental break-up, systematic studies are currently being undertaken on a wide variety of silicate and carbonate igneous rocks, from both rift and mantle-plume related settings (East and southern Africa, British Isles, India and South America), in order to constrain the geodynamic processes involved in melt generation.
- We make detailed studies of volcanoes on Iceland and oceanic spreading centres to investigate the relationship between basalt composition and mantle properties. In particular, we aim to understand the nature of thermal and compositional anomalies in the mantle and how these relate to its convective flow.
- Quantitative estimates of changes in pressure and temperature are being made using mineral solid-solution thermodynamics combined with mineral thermodynamic databases. The complexity in mineralogical composition, as revealed by mineral zoning, allows deciphering of the reactions involved in, and the paths undertaken by, rocks evolving in response to tectonic movements in the Earth's crust. Field areas include the Alps and Himalayas.
We have well-equipped geochemical laboratories for the preparation and geochemical analysis of minerals and rocks. The Department has laboratories for high pressure and temperature experiments and also for fluid dynamical investigations.
Last updated on 20-Oct-11 14:40