In 2017, we extended our cooperations to partners working in Ireland, namely Prof. Dr. Andrew Wheeler (University College Cork) and the iCRAG (Irish Centre for Research in Applied Geosciences), and jointly carried out a research cruise with Celtic Voyager (CV17013).
Onboard the R/V Celtic Voyager, the aim of the survey was to collect geophysical acoustic and seismic data in the Irish sector of the Irish Sea and the Northern Celtic Sea. The survey carried out during this cruise contributes to three iCRAG projects; 1) QuSiSS, AggrePOP and fLIPeR, which are focusing on designated windfarm areas and other areas, which were relevant for marine resources as well as the glacial history.
Glacial History, Paleovalleys and Marine Aggregates
The inland terrain of the south coast of Ireland was beyond, or near the edge of, icesheets during the last (and earlier) glaciation(s). As such, deeply incised Tertiary river valleys have been repeatedly reactivated by glacier meltwater flows draining from ice sheet and glacier fronts carrying water and sediment down system.
During glacial periods, global sea levels are lowered as the expanded icesheets stored water. During the last glaciation, sea level were around 150 m lower than present and river systems beyond the icesheets extended across the present shelf to the shelf break. As such, extensive palaeovalleys plugged with unextracted aggregate exist off the south coast of Ireland extending from existing (and abandoned) river systems onshore.
Sand and gravel aggregate deposits are a vital natural resource, providing essential raw materials. Marine aggregates have advantages over terrestrial supplies in that they are often cleaner and less prone to pyrite with improved calcium carbonate contents. Grains are often more rounded and hence more workable with reduce cement requirements.
- Delimit the seabed outcrop of drowned palaeovalleys off the south coast of Ireland and map their 3-dimensional fill
- Use this information to determine the quality and quantity of preserved marine aggregates
- Consider the geological development of the palaeovalley fills
Tóth, Zsuzsanna, McCarron S., Wheeler AJ., Wenau S., Davis S., Lim A., Spiess V. (2020) Geomorphological and seismostratigraphic evidence for multidirectional polyphase glaciation of the northern Celtic Sea. Journal of Quaternary Science 35, 465-478, https://doi.org/10.1002/jqs.3189.
Mark Coughlan, Zsuzsanna Tóth, Andrew J. Wheeler, Stefan Wenau, Stephen G. McCarron, and Volkhard Spiess - The Formation, Evolution and Characterisation of a Tunnel Valley System in the Southern Irish Sea: an Investigation of Wicklow Trough
Zsuzsanna Tóth, Andrew J. Wheeler, Stefan Wenau, Stephen G. McCarron, Mark Coughlan, Volkhard Spiess - Morphology and development of the deeps and tunnel valleys in the western Irish Sea
Zsuzsanna Tóth - Esker ridges and seismostratigraphic evidence for a southerly ice flow extending onto the present nearshore continental shelf of the Celtic Sea, SE Ireland