Graham Shields
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom;
g.shields@ucl.ac.uk |
Graham is Professor of Chemical Geology at University College London. Over the past three decades he has worked on stratigraphic correlations and paleoenvironmental interpretations of Tonian to Cambrian rock successions in Scotland, China, Mongolia, NW Africa and Australia. Graham’s research applies geochemical and isotopic tracers to better understand the co-evolution of life and the environment, including climate, oxygenation and tectonics.
From 2004 to 2012, Graham was secretary of the Neoproterozoic Subcommission and co-chaired IGCP 512 project “Neoproterozoic Ice Ages’. Subsequently, between 2012 and 2020, as chair of the Cryogenian Subcommission, he led the proposal for a chronostratigraphic definition for the base of the Cryogenian System, and its calibrated age of circa 720 Ma. He is currently chairing the ICS working group tasked with proposing a path to chronostratigraphic subdivision of pre-Cryogenian time, see here for more details: https://eartharxiv.org/repository/view/1712/ |
Cryogenian related publications:
Halverson, G.P., Porter, S.M. Shields, G.A. (2020) The Tonian and Cryogenian periods. In F. M. Gradstein (Ed.) et al., The Geologic Time Scale 2020. Elsevier Science Limited. pp. 495-519.
Shields, G.A., Mills, B.J.W., Zhu, M., Daines, S., Lenton, T.M. (2019) Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial. Nature Geoscience, 12, 823-827.
Shields G.A., Halverson, G.P., Porter, S.M. (2018) Descent into the Cryogenian. Precambrian Research, doi.org/10.1016/j.precamres.2018.08.015. 319, 1-5.
Shields, G.A., Porter, S., Halverson, G.P. (2016) A new rock-based definition for the Cryogenian Period (circa 720-635 Ma). Episodes, 39, 3-8.
Shields, G.A., Hill, A. C., Macgabhann, B. A. (2012) The Cryogenian Period. In F. M. Gradstein et al. (eds.), The Geologic Time Scale 2012. Elsevier Science Limited. doi:10.1016/B978-0-444-59425-9.00017-X.
Shields, G.A., Och, L.M. (2011) The case for a Neoproterozoic Oxygenation Event: geochemical evidence and biological consequences. GSA Today, 21(3), 4-11. doi:10.1130/GSATG102A.1.
Arnaud, E., Halverson, G. P., Shields, G.A. (eds.) (2011) The Geological Record of Neoproterozoic Glaciations. Geological Society of London Memoir 36, 721 pp.
Shields, G.A. (2005) Neoproterozoic cap carbonates: a critical appraisal of existing models and the plumeworld hypothesis. Terra Nova, 17 (4), 299-310. doi:10.1111/j.1365-3121.2005.00638.x.
Shields, G.A., Mills, B.J.W., Zhu, M., Daines, S., Lenton, T.M. (2019) Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial. Nature Geoscience, 12, 823-827.
Shields G.A., Halverson, G.P., Porter, S.M. (2018) Descent into the Cryogenian. Precambrian Research, doi.org/10.1016/j.precamres.2018.08.015. 319, 1-5.
Shields, G.A., Porter, S., Halverson, G.P. (2016) A new rock-based definition for the Cryogenian Period (circa 720-635 Ma). Episodes, 39, 3-8.
Shields, G.A., Hill, A. C., Macgabhann, B. A. (2012) The Cryogenian Period. In F. M. Gradstein et al. (eds.), The Geologic Time Scale 2012. Elsevier Science Limited. doi:10.1016/B978-0-444-59425-9.00017-X.
Shields, G.A., Och, L.M. (2011) The case for a Neoproterozoic Oxygenation Event: geochemical evidence and biological consequences. GSA Today, 21(3), 4-11. doi:10.1130/GSATG102A.1.
Arnaud, E., Halverson, G. P., Shields, G.A. (eds.) (2011) The Geological Record of Neoproterozoic Glaciations. Geological Society of London Memoir 36, 721 pp.
Shields, G.A. (2005) Neoproterozoic cap carbonates: a critical appraisal of existing models and the plumeworld hypothesis. Terra Nova, 17 (4), 299-310. doi:10.1111/j.1365-3121.2005.00638.x.