- Start date: 1 September 2018
- End date: 31 December 2019
- Funder: Leverhulme Trust
- Primary investigator: Professor Simon Poulton
This fellowship will focus will be on a geochemical study of Earth’s first rise in atmospheric oxygen around 2.3 billion years ago (termed the Great Oxidation Event; GOE). The GOE is perhaps the most significant event in Earth history in terms of the development of the Earth to its current habitable state, and witnessed the most dramatic swings in climate (from Snowball Earth conditions to runaway greenhouse conditions) the Earth has ever experienced. Indeed, the Great Oxidation Event directly sparked a chain of events that ultimately led to the evolution of our earliest animal ancestors. However, the driving forces and environmental consequences of early atmospheric oxygenation are poorly understood.
The project will employ a unique combination of state-of-the-art geochemical tools, including multiple sulfur isotopes as an indicator of atmospheric oxygenation, water column redox indicators such as Fe speciation and trace metals, and novel nutrient proxies such as phosphorus speciation. These techniques will be applied to key oceanic successions deposited in South Africa (the Transvaal Supergroup) and North America (the Huronian Supergroup), which record multiple glaciations across the GOE. Together, this approach will provide fundamental new insight into the controls, timing and impact of atmospheric oxygenation across this critical interval in the progression of the Earth to its current habitable state.