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| Titel |
Ice streaming in western Scotland and the deglaciation of the Hebrides Shelf and Firth of Lorn |
| VerfasserIn |
Riccardo Arosio, John Howe, Colm O'Cofaigh, Kirsty Crocket |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250089566
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| Publikation (Nr.) |
 EGU/EGU2014-3772.pdf |
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| Zusammenfassung |
| Previously, numerous studies have been undertaken both onshore and offshore to
decipher the morphological and sedimentological record in order to better constrain the
limits and duration of the British-Irish Ice Sheet (BIIS) (Ballantyne et al. 2009,
Bradwell et al. 2008b, Clark et al. 2011, Dunlop et al. 2010, Howe et al. 2012,
O’Cofaigh et al., 2012). Late glacial ice sheet dynamics have been revealed to be
far more rapid and responsive to climatic amelioration than had previously been
considered.
Notable in this debate has been the evidence that has been obtained in the inshore and, to
a lesser extent, offshore on the UK continental shelf. Here new geomorphological data,
principally multibeam echo sounder (MBES) data has provided imagery of previously unseen
features interpreted as being glacial in origin.
In the wake of these new discoveries this projects aims to investigate the extent, timing,
growth and final disintegration of the BIIS across Western Scotland. This area of
particular interest for the development of the glaciated North Atlantic margin has been
generally neglected in past studies, especially across the mid-outer shelf, which
constitutes a missing part in the jigsaw of the reconstructed BIIS during the last
~20.000yrs.
We aim to mainly focus on geomorphological analyses of MBES data collected in the
Firth of Lorn and Sea of Hebrides; a study of features as moraines, glacial lineations and
drumlins will provide important clues on the dynamics and maximum extension of the
sheet.
Subsequently we will examine the geometry and composition of the shelf sediment
infill, aiming to constrain the influence of ice retreat on depositional environments
using multi-element geochemical (Pb-isotopes ratios, 14C and OSL dating) and
sedimentological techniques. Such an investigation will also give retrospective information
on the sources for these sediments, hence more indications on ice configuration.
Ultimately we aim to provide a model of deglaciation for the western sector of the
BIIS.
Keywords: British-Irish Ice Sheet, NW Scotland, glacial bedforms, geochronology
References
Ballantyne, C.K., Schnabel, C. & Xu, S. 2009. Readvance of the last British Ice Sheet
during Greenland Interstade (GI-1): the Wester Ross Readvance, NW Scotland. Quaternary
Science Reviews, 28, 783-789
Bradwell, T., Fabel, D., Stoker, M., Mathers, H., McHargue, L., Howe, J., 2008b. Ice caps
existed throughout the Late glacial interstadial in northern Scotland. Journal of Quaternary
Science 23, 401-407.
Clark, C.D., Hughes, A.L.C., Greenwood, S.L., Jordan, C., Sejrup, H.P. 2012.
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Dunlop, P., Shannon, R., McCabe, M., Quinn, R., Doyle, E. 2010. Marine geophysical
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O’ Cofaigh, C., Dunlop, P. Benetti, S., 2012. Marine geophysical evidence for Late
Pleistocene ice sheet extent and recession off northwest Ireland, Quaternary Science Reviews.
In press. |
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