PhD: Wildfires as an agent of geochemical and mineralogical differentiation at the Earth’s surface

Fires have affected large parts of the Earth's surface since the Devonian; they potentially exert a significant influence on the mineralogical and geochemical characteristics of an environment that is otherwise considered to be dominated by low temperature processes. A lack of suitable sampling media means that the impact of high intensity fires has proven difficult to test, but recent work identifies magnetic iron pisoliths as a promising archive. Magnetic Fe pisoliths contain a high temperature mineral assemblage including maghemite & chi alumina, requiring >> 500 0C to form. Their presence in soils and weathering profiles around the world demonstrates that intense fires have an important role to play in landscape evolution. In addition, our recent work suggests that the geochemical fractionation associated with the formation and subsequent weathering of these wildfire products results in highly unusual sediment trace element patterns across the Australian continent.

Here we look for a highly motivated PhD candidate to undertake a detailed mineralogical and geochemical study of samples of Fe pisoliths sampled before and after major bush fire events in Australia, Southern Africa and California. This will provide important constraints on the formation of magnetic Fe pisoliths that can then be applied to ancient examples, providing an entirely new perspective of the role of fire in the Earth system. The candidate will be expected to use a variety of mineralogical and geochemical techniques to investigate the Fe pisoliths including XRD, SEM, Raman spectroscopy, EPMA, EBSD, LA-ICPMS and potentially synchrotron source techniques. The candidate is expected to have a manual drivers licence, ideally some 4wd experience and have experience of field work in remote locations.

For further information and to apply please contact

posted: 07 February 2017     Please mention EARTHWORKS when responding to this advertisement.