Postdoctoral Associate

phone (617) 230 2860
email gizon@mit.edu

Department of Earth, Atmospheric and Planetary Sciences
Massachusetts Institute of Technology
E25-631, 45 Carleton Street
Cambridge, MA 02139
USA

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Bio

2016-present –Postdoctoral Associate, , Light-Stable Isotope Geochemistry, MIT, USA.
2013-2016 – Postdoctoral Research Associate, Light-Stable Isotope Geochemistry, St Andrews University, UK.
2013-2016 – Visiting Research Associate, University of Leeds, UK.
2013-2016– Visiting Research Associate, University of Maryland, USA.
2008-2012 – PhD, Trace Element and Isotope Geochemistry, The Open University, UK.
2007-2008 – MSc, Geochemistry, The University of Leeds, UK.
2004-2007 – BSc, Geological Sciences, The University of Leeds, UK.

Research

I have very broad research interests having worked on a variety of events over varying timescales that encompass the majority of Earth’s history. In the broadest sense I am interested in the exploitation of elemental and isotopic proxies to answer a broad range of pertinent geological, palaeoceanographic and low-temperature geochemical questions. At the heart of my research is the desire to develop an understanding of the causes and consequences of transient aberrations in the Earth system (e.g. marine anoxia, climate change and mass extinctions), their effects on global biogeochemical cycles and the implications for the biosphere, both in the past and as a consequence of anthropogenic negligence.

More recently I have become increasingly fascinated with the quadruple sulphur-isotope record. The “mass-independency” of the S-isotope record has been used extensively since its discovery to chart the rise in atmospheric oxygen; however, if we consider its secular evolution, the route to its demise at the GOE is far from straightforward: displaying variable magnitude and changeable relationships between the minor S-isotopes (∆36S/∆33S). Understanding how to read this rich tapestry of information is central to answering key questions surrounding the evolution of the biosphere, its affect on planetary chemistry, and ultimately how our planet transitioned towards the habitable oxygenated planet we’re all familiar with today. All of which have ramifications for the search for life outside of our solar system.

In this vein, during my time at MIT I will be constructing high-resolution quadruple-S, nitrogen and carbon isotope records from newly cored continuous expressions of the Great Oxidization Event (GOE) obtained from the Transvaal Supergroup, South Africa. These data will provide unprecedented insight into the directionality, and timing of planetary oxygenation, whilst providing a robust framework for future research on the coevolution of Earth’s life and the surface environment.

Select Publications

Google scholar citations

  • Mettam C., Zerkle, A.L., Claire, M.W., Izon, G., Junium, C.J., Twitchett, R.T., (2017) High-frequency fluctuations in redox conditions during the latest Permian mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology, 485; 210–230. doi: 10.1016/j.palaeo.2017.06.014
  • Izon, G., Zerkle, A.L., Williford, K.H., Farquhar, J., Poulton, S.W. and Claire, M.W. (2017), Biological regulation of atmosphere chemistry en route to planetary oxygenation. Proceedings of the National Academy of Sciences, doi: 10.1073/pnas.1618798114.
  • Izon, G., Zerkle, A.L., Zhelezinskaya, Y., Farquhar, J., Newton, R.J., Poulton, S.W., Eigenbrode, J.L & Claire. M.W. (2015), Multiple Oscillations in Neoarchaean Atmospheric Chemistry. Earth and Planetary Science Letters, 431; 264–273.
  • Miller, C.S., Leroy, S.A.G., Izon, G., Lahijani, H.A.K., Marret, F., Cundy, A.B. & Teasdale, P.A. (2013), Palynology: A tool to identify abrupt events? An example from Chabahar Bay, southern Iran. Marine Geology, 337; 195–201.
  • Goldberg, T., Gordon, G., Izon, G., Archer, C., Pearce, C.R., McManus, J., Anbar, A., and Rehkämper, M. (2013). Resolution of inter-laboratory discrepancies in Mo-isotope data: An intercalibration. Journal of Analytical Atomic Spectrometry, 28; 724–735.
  • Bond, D.P., Wignall, P.B., Wang, W., Izon, G., Jiang, H., Lai, X., Sun, Y., Newton, R.J., Shao, L., Vedrine, S., Cope, H., (2010). Mid-Capitanian middle Permian mass extinction and carbon isotope record of South China. Palaeogeography, Palaeoclimatology, Palaeoecology, 292; 282–294.
  • Wignall, P.B., Sun, Y., Bond, D.P., Izon, G., Newton, R.J., Vedrine, S., Widdowson, M., Ali, J.R., Lai, X., Jiang, H., Cope, H., Bottrell, S.H. (2009). Volcanism, mass extinction, and carbon isotope fluctuations in the Middle Permian of China. Science, 324; 1179–1182.