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dc.contributor.authorBallantyne, Colin
dc.contributor.authorStone, John O.
dc.date.accessioned2015-01-19T14:31:04Z
dc.date.available2015-01-19T14:31:04Z
dc.date.issued2015-04
dc.identifier.citationBallantyne , C & Stone , J O 2015 , ' Trimlines, blockfields and the vertical extent of the last ice sheet in southern Ireland ' , BOREAS , vol. 44 , no. 2 , pp. 277-287 . https://doi.org/10.1111/bor.12109en
dc.identifier.issn0300-9483
dc.identifier.otherPURE: 162210320
dc.identifier.otherPURE UUID: 51b1a5f9-a888-42b2-84db-a2a036e9d1df
dc.identifier.otherScopus: 84925643193
dc.identifier.otherWOS: 000351852200002
dc.identifier.urihttp://hdl.handle.net/10023/6021
dc.descriptionThe research reported here was supported by UK NERC grant NER/B/S/2001/0919en
dc.description.abstractTrimlines separating glacially abraded lower slopes from blockfield-covered summits on Irish mountains have traditionally been interpreted as representing the upper limit of the last ice sheet during the Last Glacial Maximum (LGM). Cosmogenic 10Be exposure ages obtained for samples from glacially deposited perched boulders resting on blockfield debris on the summit area of Slievenamon (721 m a.s.l.) in southern Ireland demonstrate emplacement by the last Irish Ice Sheet (IIS), implying preservation of the blockfield under cold-based ice during the LGM, and supporting the view that trimlines throughout the British Isles represent former englacial thermal regime boundaries between a lower zone of warm-based sliding ice and an upper zone of cold-based ice. The youngest exposure age (22.6±1.1 or 21.0±0.9 ka, depending on the 10Be production rate employed) is statistically indistinguishable from the mean age (23.4±1.2 or 21.8±0.9 ka) obtained for two samples from ice-abraded bedrock at high ground on Blackstairs Mountain, 51 km to the east, and with published cosmogenic 36Cl ages. Collectively, these ages imply (i) early (24–21 ka) thinning of the last IIS and emergence of high ground in SE Ireland; (ii) relatively brief (1–3 ka) glacial occupation of southernmost Ireland during the LGM; (iii) decoupling of the Irish Sea Ice Stream and ice from the Irish midlands within a similar time frame; and (iv) that the southern fringe of Ireland was deglaciated before western and northern Ireland.
dc.format.extent11
dc.language.isoeng
dc.relation.ispartofBOREASen
dc.rights© 2015. The Authors. Boreas published by John Wiley & Sons Ltd on behalf of The Boreas Collegium. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.en
dc.subjectG Geography (General)en
dc.subjectQE Geologyen
dc.subjectNDASen
dc.subject.lccG1en
dc.subject.lccQEen
dc.titleTrimlines, blockfields and the vertical extent of the last ice sheet in southern Irelanden
dc.typeJournal articleen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews.Geography & Sustainable Developmenten
dc.identifier.doihttps://doi.org/10.1111/bor.12109
dc.description.statusPeer revieweden


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