High-resolution record of the deglaciation of the British-Irish Ice Sheet from North Atlantic deep-sea sediments.

Serena Tarlati, S. Benetti, Louise Callard, Colm O'Cofaigh, P Dunlop, Richard Chiverrell, Derek Fabel, Steven Moreton, Chris D Clark

Research output: Contribution to conferencePoster

Abstract

During the last glacial maximum the British-Irish Ice Sheet (BIIS) covered the majority of Ireland and Britain. Recent studies have described the BIIS as largely marine-based and highly dynamic with several advances and retreats recorded on the continental shelf.
The focus of this study is the more recent sediment record from the Donegal Barra Fan (DBF), the largest sediment depocentre formed by the ice streaming of the western BIIS onto the North Atlantic continental margin.

In this project, well-preserved, glacially-derived, deep-water sediments from 3 cores, up to 6.7 m long and retrieved from the DBF, are used to investigate and chronologically constrain the pattern of deglaciation of the BIIS. Deep-water sediments can record continuous sedimentation through time, avoiding hiatuses and erosional surfaces characteristic of a glacial environment and allow a detailed reconstruction of deglacial processes.

Five lithofacies have been identified using sedimentology, x-rays, physical properties and grain size analysis. They include bioturbated foraminifera-bearing muds, interpreted as hemipelagic and contouritic deposits from interglacial periods. Chaotic and laminated muds, ice-rafted debris (IRD)-rich layers and laminated mud to sand couplets are characteristic of the glacial period including ice-sheet maximum extent and the beginning of retreat. These represent downslope mass movements, plumites from meltwater alongside melting icebergs and turbidites. Radiocarbon dates from foraminifera suggest that the deglacial sedimentary sequence is up to 5m thick. The IRD concentration and abundance of the foraminifera Neogloboquadrina pachyderma sinistral indicate a minimum of 3 different calving events during deglaciation and a marked Younger Dryas cooling and ice calving period. Additionally the δ 18O record will be used to investigate the record of climatic changes in the region and x-ray fluorescence will be used to assess sediment provenance during deglaciation.
Original languageEnglish
Number of pages1
Publication statusPublished - 16 Dec 2016
EventAmerican Geophysical Union: Fall Meeting - Moscone Center, San Francisco, United States
Duration: 12 Dec 201616 Dec 2016

Conference

ConferenceAmerican Geophysical Union
Abbreviated titleAGU Fall Meeting
CountryUnited States
CitySan Francisco
Period12/12/1616/12/16

Keywords

  • British Irish Ice Sheet
  • Deglaciation
  • Donegal-Barra Fan

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  • Research Output

    Final deglaciation of the Malin Sea through meltwater release and calving events

    Tarlati, S., Benetti, S., Callard, L., Ó Cofaigh, C., Dunlop, P., Georgiopoulou, A., Edwards, R., Van Landeghem, K. J. J., Saher, M., Chiverrell, R., Fabel, D., Moreton, S., Morgan, S. & Clark, C. D., 6 Apr 2020, In : Scottish Journal of Geology.

    Research output: Contribution to journalArticle

  • Cite this

    Tarlati, S., Benetti, S., Callard, L., O'Cofaigh, C., Dunlop, P., Chiverrell, R., Fabel, D., Moreton, S., & Clark, C. D. (2016). High-resolution record of the deglaciation of the British-Irish Ice Sheet from North Atlantic deep-sea sediments.. Poster session presented at American Geophysical Union, San Francisco, United States.