Constraining large igneous province volcanism and global weathering rates during super-greenhouse climates
Lead supervisor: Dr Weimu Xu (University College Dublin)
Earth history is marked by major climatic and environmental change events, often associated with major global carbon cycle perturbations, widespread marine anoxia and ecological/biological disturbance. These events have been linked to Large Igneous Province (LIP) volcanism, through which millions of cubic kilometres of volcanic (basaltic) rock were emplaced onto the Earth surface within 104-106 years, potentially leading to the rapid and massive release of greenhouse gasses (e.g. CO2 CH4) into the ocean-atmosphere system. Increases in atmospheric carbon dioxide concentrations resulted in global warming and intensified hydrological cycling, thereby enhancing physical/chemical weathering and nutrient supply to marine and continental basins.
Silicate weathering is an important carbon sink in the global carbon cycle at geological timescales. A novel geochemical proxy used to trace changes in the contribution of continental silicate-weathering and/or the weathering of subaerial/marine LIPs through time is the change in the Osmium (Os) isotopic composition of global seawater, as recorded in sedimentary archives.
The project will utilise this proxy to study sedimentary rocks from the Early Jurassic and Paleogene, spanning some of the largest global change events in Earth history, including the end-Triassic mass extinction, the Toarcian Oceanic Anoxic Event and the Paleocene/Eocene Hyperthermals, to disentangle the complex history of changes in the global weathering rates and Large Igneous Province volcanism at these times.
The project will focus on samples from a recently drilled ICDP (International Continental Drilling Program) and IODP (International Ocean Discovery Program) cores. This will enable the student to engage/collaborate with the wider international paleoclimate science community.
The student will receive training in sedimentology, stratigraphy, geochemistry, carbon cycling, palaeoceanography and palaeoclimatology. They will also receive specific training in the use of metal-free laboratories and analytical methods (ICP-MS, MCICP-MS, TIMS), at the National Centre for Isotope Geochemistry, School of Earth Sciences, University College Dublin.
Applications are invited from students who can demonstrate a solid background in inorganic geochemistry, stratigraphy and/or palaeoclimatology. Passion for laboratory work, as well as core sampling and/or fieldwork, and a keen interest and self-motivation for solving problems is essential. Candidates must have an excellent, relevant geoscience honours degree or a geoscience MSc degree.
The successful applicant for this project will be based at the School of Earth Sciences, University College Dublin. The project is funded by a 4 year, fully-funded scholarship (both EEA/EU and non-EEA/EU applicants are eligible to apply). It covers university tuition fees, an annual tax-free stipend of €18,000, and a project-specific research grant covering research expenses and conferences.
The project has an envisioned start date of 1st September 2021.
How to apply
To apply, please send by e-mail (1) a full CV (including publications, conference abstracts, if any), (2) a cover letter stating why you are interested in this project, and why you and your academic background make you the ideal candidate for this project, and (3) the names and contact details of two academic referees to Dr Weimu Xu (email@example.com).
Enquiries for further details can be directed to Dr Weimu Xu.
Closing date: 16th of May 2021 (Evaluations and interviews are planned soon thereafter).
Equality, diversity, and inclusion
UCD is committed to creating an inclusive environment where diversity is celebrated, and everyone is afforded equality of opportunity. To that end the university adheres to a range of equality, diversity and inclusion policies. We encourage applicants to consult those policies here https://www.ucd.ie/equality/. We welcome applications from everyone, including those who identify with any of the protected characteristics that are set out in our Equality, Diversity and Inclusion policy.