Carbon emissions from volcanism: the Karoo-Ferrar large igneous province and the Toarcian Oceanic Anoxic Event

Many of the most severe climate ‘events’ and carbon cycle perturbations of the Meso-Cenozoic coincide with major episodes of volcanism linked to Large Igneous Provinces (LIPs). One of the most extreme examples is the end-Toarcian oceanic anoxic event, a global climate change event which roughly coincides with the emplacement of the Karoo and Ferrar large igneous provinces (located today in South Africa and Antarctica, respectively). LIPs like Karoo and Ferrar supply carbon-based greenhouse gases to the atmosphere by two main mechanisms: 1) Carbon dioxide, released from both intruded and erupted magma and 2) Thermogenic methane, formed when shallow igneous sills intrude organic matter-rich sedimentary rock, and emitted via hydrothermal vents. But the quantity, relative timing, and rates of carbon emissions from the Karoo-Ferrar province are poorly known because we lack information both about the intrusive volcanism itself and the chemical composition of the host rock into which it intruded. Was this volcanism truly sufficient to drive the dramatic climate perturbation of the Toarcian OAE? Or was the volcanic carbon release relatively minor or simply too slow to explain Toarcian climate observations?
This PhD project will combine fieldwork, lab geochemistry, and literature/database assimilation to constrain the carbon emissions from the Karoo-Ferrar province. This will include traditional field geology and collection of structural information on the ground in Karoo, as well as seismic and/or satellite interpretation of sill dimensions for Karoo and/or Ferrar provinces.
The project will include one or more field trips to the Karoo province in South Africa as part of a large team of international collaborators. In addition to supervisors Greene and Jones, the team will include leading international experts on Mesozoic sedimentology, stratigraphy, and geochronology Prof. Aisha Al-Suwaidi (Khalifa University, United Arab Emirates) and Prof. Micha Ruhl (Trinity College Dublin). Further collaborations with the British Antarctic Survey will explore the nature of the Ferrar LIP from seismic data.
Please contact Dr Sarah Greene ([Email Address Removed]) or Steve Jones ([Email Address Removed]) for further information or to discuss the project in greater detail.