Late Quaternary evolution and sea-level history of a glaciated marine embayment, Bantry Bay, SW Ireland
Plets, R.M.K.; Callard, S.L.; Cooper, J.A.G.; Long, A.J.; Quinn, R.J.; Belknap, D.F.; Edwards, R.J.; Jackson, D.W.T.; Kelley, J.T.; Long, D.; Milne, G.A.; Monteys, X. (2015). Late Quaternary evolution and sea-level history of a glaciated marine embayment, Bantry Bay, SW Ireland. Mar. Geol. 369: 251-272. https://dx.doi.org/10.1016/j.margeo.2015.08.021 In: Marine Geology. Elsevier: Amsterdam. ISSN 0025-3227; e-ISSN 1872-6151, more |  |
| Keyword | | | Author keywords | Relative sea-level change; Post-glacial transgression; Multibeam echosounder; Seismo-stratigraphy; Litho-stratigraphy; Bantry Bay |
| Authors | | Top | - Plets, R.M.K., more
- Callard, S.L.
- Cooper, J.A.G.
- Long, A.J.
| - Quinn, R.J.
- Belknap, D.F.
- Edwards, R.J.
- Jackson, D.W.T.
| - Kelley, J.T.
- Long, D.
- Milne, G.A.
- Monteys, X.
|
| Abstract | Ireland experienced a spatially complex pattern of relative sea-level (RSL) changes and shoreline development caused by the interplay of isostatic and eustatic (ice equivalent sea level) processes since the Last Glacial Maximum (LGM). Using a combination of high-resolution marine geophysical data, vibrocores, foraminiferal analysis and 10 AMS radiocarbon dates, we reconstruct the Late Quaternary evolution and RSL history of Bantry Bay, a large (40 km long, 5–10 km wide) embayment in SW Ireland.The data indicate two infill phases: one before and one after the LGM, separated by glacial and lowstand sediments. The pre-LGM history is not dated and the depositional history is inferred. A large sediment lobe formed at the outer edge of Bantry Bay as a lowstand ice-proximal glacimarine outwash system as the ice retreated after the LGM, at a sea level ca. 80 m lower than present. Iceberg scour immediately west of this location likely relate to the break-up of the local Kerry–Cork Ice Cap. Long curvilinear ridges, seen both offshore and on top of the sediment lobe, probably formed as shoreface ridges under stronger-than-present tidal currents during a period of RSL stability (pre-14.6 ka cal BP). A subsequent infill phase is characterised by a basin-wide erosional (ravinement) surface and the deposition of inter- and sub-tidal estuarine sediments. Although our data support the general trends, our stratigraphic and radiocarbon data suggest a higher sea level between 11 and 13.5 ka cal BP than predicted by existing glacial isostatic adjustment models. |
|
