St Andrews Research Repository

St Andrews University Home
View Item 
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  • Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

Late Quaternary glaciation in the Hebrides sector of the continental shelf : cosmogenic nuclide dating of glacial events on the St Kilda archipelago

Thumbnail
View/Open
Ballantyne_2017_Boreas_LateQuaternaryGlaciation_AAM.pdf (2.200Mb)
Date
10/2017
Author
Ballantyne, Colin K.
Fabel, Derek
Gheorghiu, Delia
Rodés, Ángel
Shanks, Richard
Xu, Sheng
Keywords
GE Environmental Sciences
NDAS
Metadata
Show full item record
Abstract
The St Kilda archipelago lies ~65 km west of the Outer Hebrides and ~60 km east of the Atlantic shelf break, and represents a key site for testing the assertion that during the Last Local Glacial Maximum (LLGM; c. 27 ka) the British–Irish Ice Sheet (BIIS) extended to near the shelf edge in all sectors. Two consistent cosmogenic 36Cl exposure ages averaging (≥) 81.6±7.8 ka for perched boulders at 290 m altitude demonstrate that the last ice sheet failed to over-run high ground on the largest island, Hirta. 36Cl and 10Be exposure ages for glacially emplaced boulders on low ground indicate deposition by small, locally nourished glaciers that last occupied a north-facing valley (Gleann Mòr) at c. 30.9±3.2 ka, prior to extension of the last ice sheet to the outer shelf, and a south-facing valley (Village Bay) at c. 19.2±2.3 ka, several millennia after the LLGM. Our dating evidence is consistent with previous interpretations of lithostratigraphical, seismostratigraphical and geomorphological evidence and confirms that the last ice sheet failed to encroach on St Kilda. A simple ice-flow model demonstrates that even if thin, low-gradient ice lobes encircled the archipelago during the LLGM, the ice margin can only have reached the outermost moraine banks, ~40 km west of St Kilda, under extremely low (<2 kPa) driving stresses, implying either surge-like transient streaming behaviour at the ice-sheet margin or that the moraine banks relate to an earlier, more extensive ice sheet. The final glaciation of the Village Bay area at c. 19.2±2.3 ka was out of phase with the behaviour of the BIIS, which was undergoing net retreat during this period.
Citation
Ballantyne , C K , Fabel , D , Gheorghiu , D , Rodés , Á , Shanks , R & Xu , S 2017 , ' Late Quaternary glaciation in the Hebrides sector of the continental shelf : cosmogenic nuclide dating of glacial events on the St Kilda archipelago ' , BOREAS , vol. 46 , no. 4 , pp. 605-621 . https://doi.org/10.1111/bor.12242
Publication
BOREAS
Status
Peer reviewed
DOI
https://doi.org/10.1111/bor.12242
ISSN
1502-3885
Type
Journal article
Rights
© 2017 Collegium Boreas. Published by John Wiley & Sons Ltd. This work has been made available online in accordance with the publisher’s policies. This is the author created accepted version manuscript following peer review and as such may differ slightly from the final published version. The final published version of this work is available at: https://doi.org/10.1111/bor.12242xxxx
Description
The authors thank NERC-CIAF for funding analysis of the 10Be and 36Cl exposure ages (Allocation 9116/0412), the Carnegie Trust for the Universities of Scotland for a grant towards travel expenses.
Collections
  • University of St Andrews Research
URI
http://hdl.handle.net/10023/13226

Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

Advanced Search

Browse

All of RepositoryCommunities & CollectionsBy Issue DateNamesTitlesSubjectsClassificationTypeFunderThis CollectionBy Issue DateNamesTitlesSubjectsClassificationTypeFunder

My Account

Login

Open Access

To find out how you can benefit from open access to research, see our library web pages and Open Access blog. For open access help contact: openaccess@st-andrews.ac.uk.

Accessibility

Read our Accessibility statement.

How to submit research papers

The full text of research papers can be submitted to the repository via Pure, the University's research information system. For help see our guide: How to deposit in Pure.

Electronic thesis deposit

Help with deposit.

Repository help

For repository help contact: Digital-Repository@st-andrews.ac.uk.

Give Feedback

Cookie policy

This site may use cookies. Please see Terms and Conditions.

Usage statistics

COUNTER-compliant statistics on downloads from the repository are available from the IRUS-UK Service. Contact us for information.

© University of St Andrews Library

University of St Andrews is a charity registered in Scotland, No SC013532.

  • Facebook
  • Twitter