Project proposal Bright Minds Assistantships February 2022
Refining the stratigraphy of North Sea sediments using volcanic ash
Tephrochronology of the Southern North Sea during MIS 5 and 4.
Department: Physical geography
Research group: Quaternary Climate and Landscape
Supervisors: Irene Waajen, Amy McGuire (University of Leeds, UK), Wim Hoek Email address: irene.waajen@tno.nl
Project description
This assistantship is part of a collaborative project between the University of Utrecht, University of Leeds and TNO-Geological Survey of the Netherlands, focusing on sea level variations and landscape reconstruction of the Southern North Sea during the Early Weichselian (late MIS 5 and 4, ca. 100 to 60 ka BP). Dating of these sediments has proven difficult, but the location potentially contains ash traces from Icelandic and Eifel volcanic provinces. Whilst no visible tephra (volcanic glass shards) deposits have been identified within the sequence, several widespread MIS 5 and 4 tephra markers, primarily of Icelandic origin, have been found throughout the North Atlantic. Given the known dispersal potential of Icelandic eruptions, we aim to identify these tephra horizons, and potentially others, through detailed analysis of sediments from the Southern North Sea. The identification of non-visible volcanic ash horizons
(‘cryptotephras’) will allow us to correlate a new record of past environmental changes more precisely and accurately to oceanic palaeoclimate records which contain tephra from the same eruption. This study will develop the first tephrostratigraphic record for the Southern North Sea spanning MIS 5 and 4.
We seek a motivated student with eye for detail to carry out cryptotephra extraction and identification. You will apply established protocols and will be trained in cryptotephra identification using microscopy. The project will be challenging but if found, tephra identification will be a major step forward for regional sediment chronology of the Early Weichselian. Tephra samples will be tied to volcanic sources using geochemical techniques (WDS-EPMA, LA-ICPMS).
In case of COVID restrictions, we might adapt part of the lab-work for sample preparation. Both ESL and GML laboratories have clear COVID protocols which will be followed. Most lab work can be done while social distancing 1.5 meters, and will be continued as much as possible.
Suggested reading:
- Abbott, P. M., Griggs, A. J., Bourne, A. J., Chapman, M. R., & Davies, S. M. (2018). Tracing marine cryptotephras in the North Atlantic during the last glacial period: Improving the North Atlantic marine tephrostratigraphic framework. Quaternary Science Reviews, 189, 169-186.
- Abbott, P. M., Griggs, A. J., Bourne, A. J., & Davies, S. M. (2018). Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls. Marine Geology, 401, 81-97.
- Davies, S.M. (2015), Cryptotephras: the revolution in correlation and precision dating. J. Quaternary Sci., 30: 114-130.
- Turney, C. S., Lowe, J. J., Davies, S. M., Hall, V., Lowe, D. J., Wastegård, S., Hoek, W.Z. & Alloway, B. (2004). Tephrochronology of Last Termination sequences in Europe: a protocol for improved analytical precision and robust correlation procedures (a joint SCOTAV–INTIMATE proposal). Journal of Quaternary Science, 19(2), 111-120.
Job requirements
Preferably have some microscope experience, eye for detail and good communication skills.
Knowledge of late Pleistocene stratigraphy, interest in lab work, tephrostratigraphy, paleoclimatology and/or mineralogy is required.
