Exploring the use of tephrostratigraphy to constrain the rates of Last Interglacial sea-level change

Supervisor: Dr Natasha Barlow

Department: School of Earth and Environment, University of Leeds

Description:

This placement will embedded you within the European Research Council funded RISeR project https://riser.leeds.ac.uk/ which seeks to understand the rates of Last Interglacial sea-level change, and the nature of landscape responses.  We have collected 5 exciting new cores which record the flooding of the North Sea basin during the Last Interglacial (c.120,000 years ago).  Dating sediments of this age is a challenge, and we are working on techniques which utilise biostratigraphy and OSL dating.  Tephrochronology uses the identification of volcanic ash deposits within sedimentary sequences to establish chronostratigraphic markers and has widely been applied in Holocene and postglacial palaeoenvironmental reconstructions.  Until now, no tephra deposits have been recorded in the southern North Sea, however, having observed a few glass shards in our pollen slides, we are keen to pursue more detailed study. Therefore, the student will have the opportunity to take part in a large research project and work on developing the first tephrostratigraphy from the southern North Sea.

Working together with the project team (Dr Natasha Barlow, Dr Amy McGuire, and Dr Graham Rush) the student will select the cores which are most suited to their interest (the Last Interglacial highstand, or the falling sea-level towards the Last Glacial in the Brown Bank member).  The student will work within the School of Earth and Environment micropalaeo laboratory and will use established cryptotephra extraction techniques, alongside high-powered microscopy, to identify volcanic glass shards within the North Sea cores, with a view to linking them to past volcanic eruptions. Should COVID-19 mean that in-person lab work is not feasible, we have an extensive core-scanned XRF dataset which could be explored to identify tephra using geochemical techniques through a desk-based study.

The student will join our biweekly project meeting with the wider team, as well as attend our monthly extended laboratory meeting which focuses on the core analysis undertaken within the project in detail.  The candidate will be supported on a day-to-day basis by Dr Amy McGuire who has experience of working in the Cambridge Tephra Laboratory.  There will be scope to contribute to a publication on the RISeR core chronologies following the placement.  This project would suit anyone with laboratory experience, who wishes to explore new techniques and timescales. You do not need experience of working with tephra or a microscope – all training and equipment will be provided.