Scotland - Ian Cawood
Ian is a final year BSc Geology student at the University of St Andrews. During his time at St Andrews, Ian has been involved in extensive field work and a diverse range of research projects. Most recently, Ian was funded by the MIS and IOM3 to complete field work as part of his final year dissertation in the French Pyrenees for 6 weeks, mapping a complex shear zone over the Saint Barthelemy Massif. His interest in both field and lab work has led to his most recent work on the Greendale Appinite Complex in Nova Scotia.
In 2019, Ian plans to undertake a PhD to unravel the processes responsible for the formation of continental crust through its generation and stabilisation in modern and ancient mountain belts. In particular, he is interested in the tectonothermal evolution of the crust associated with orogenesis; the process of thickening and stabilising the crust through structural, metamorphic and magmatic processes. His aim is to do this through integrated field and geochemical studies.
Ian is currently completing his dissertation work and studying for final year exams. Away from work, he enjoys swimming, tennis, hill walking and playing music.
Water and the earth's crust: The role and source of water in a crystallising magma
Appinites are amphibole rich plutonic rocks that typically form in convergent to collisional tectonic settings. Amphibole is a mineral that uniquely records magma chamber through its isotopic ratios of D/H and 18O/16O thus informing on magma transport, storage and evolution in the crust.
Two generations of amphiboles in the Greendale Complex appinites are identified: one derived from the mantle (δ18O 4.8 - 6.8‰) and the other from the crust (δ18O 0.9 - 4.7‰). δD isotopic signatures are favoured to be the result of mixing between a region of mantle upwelling and a subducting slab, allowing for hydration of the magma during ascent.
Appinites are widely believed to be the result of asthenospheric upwelling. The collected δD and δ18O isotopic data provides firm evidence in support of this interpretation and suggests that appinitic complexes may be tracer of such processes.