Smedley, RK and Scourse, JD and Small, D and Hiemstra, JF and Duller, GAT and Bateman, MD and Burke, MJ and Chiverrell, RC and Clark, CD and Davies, SM and Fabel, D and Gheorghiu, DM and McCarroll, D and Medialdea, A and Xu, S (2017) New age constraints for the limit of the British–Irish Ice Sheet on the Isles of Scilly. Journal of Quaternary Science, 32 (1). 48 -62. ISSN 0267-8179

[img]
Preview
Text
Smedley et al 2017 (JQS) - Isles of Scilly, UK.pdf - Published Version
Available under License Creative Commons Attribution.

Download (11MB) | Preview

Abstract

The southernmost terrestrial extent of the Irish Sea Ice Stream (ISIS), which drained a large proportion of the last British–Irish Ice Sheet, impinged on to the Isles of Scilly during Marine Isotope Stage 2. However, the age of this ice limit has been contested and the interpretation that this occurred during the Last Glacial Maximum (LGM) remains controversial. This study reports new ages using optically stimulated luminescence (OSL) dating of outwash sediments at Battery, Tresco (25.5 +/- 1.5 ka), and terrestrial cosmogenic nuclide exposure dating of boulders overlying till on Scilly Rock (25.9 1.6 ka), which confirm that the ISIS reached the Isles of Scilly during the LGM. The ages demonstrate this ice advance on to the northern Isles of Scilly occurred at ~26 ka around the time of increased ice-rafted debris in the adjacent marine record from the continental margin, which coincided with Heinrich Event 2 at ~24 ka. OSL dating (19.6 +/- 1.5 ka) of the post-glacial Hell Bay Gravel at Battery suggests there was then an ~5-ka delay between primary deposition and aeolian reworking of the glacigenic sediment, during a time when the ISIS ice front was oscillating on and around the Llyn Peninsula, ~390km to the north.

Item Type: Article
Uncontrolled Keywords: British–Irish Ice Sheet, ice stream, Last Glacial Maximum, OSL,TCN
Subjects: G Geography. Anthropology. Recreation > GB Physical geography
Divisions: Faculty of Natural Sciences > School of Geography, Geology and the Environment
Depositing User: Symplectic
Date Deposited: 16 Feb 2017 16:34
Last Modified: 16 Feb 2017 16:34
URI: http://eprints.keele.ac.uk/id/eprint/2904

Actions (login required)

View Item View Item