Volume 21 Issue 3 (March 2011)
GSA TODAY
Article, pp. 4-11
The case for a Neoproterozoic Oxygenation Event: Geochemical evidence and biological consequences
Graham Shields-Zhou1*, Lawrence Och2*
1 Dept. of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK, and LPS, Nanjing Institute of Geology and Palaeontology (NIGPAS), Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China
2 Dept. of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
ABSTRACT
The Neoproterozoic era marked a turning point in the development of the modern earth system. The irreversible environmental changes of that time were rooted in tectonic upheavals that drove chain reactions between the oceans, atmosphere, climate, and life. Key biological innovations took place amid carbon cycle instability that pushed climate to unprecedented extremes and resulted in the ventilation of the deep ocean. Despite a dearth of supporting evidence, it is commonly presumed that a rise in oxygen triggered the evolution of animals. Although geochemical evidence for oxygenation is now convincing, our understanding of the Neoproterozoic earth system and of early animal evolution has changed apace, revealing an altogether more complicated picture in which the spread of anoxia played an important role. The challenge to future researchers lies in unraveling the complex entanglement of earth system changes during this pivotal episode in Earth’s history.
*E-mail: g.shields@ucl.ac.uk, l.och@ucl.ac.uk
Manuscript received 5 May 2010; accepted 16 June 2010
DOI: 10.1130/GSATG102A.1
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