Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka
Understanding how marine-based ice streams operated during episodes of deglaciation requires geochronological data that constrain both timing of deglaciation and changes in their flow behaviour, such as that from unconstrained ice streaming to topographically restricted flow. We present seventeen ne...
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ftuglasgow:oai:eprints.gla.ac.uk:140270 2023-05-15T16:38:12+02:00 Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka Small, David Benetti, Sara Dove, Dayton Ballantyne, Colin K. Fabel, Derek Clark, Chris D. Gheorghiu, Delia M. Newall, Jennifer Xu, Sheng 2017-07-01 text http://eprints.gla.ac.uk/140270/ http://eprints.gla.ac.uk/140270/1/140270.pdf en eng Elsevier http://eprints.gla.ac.uk/140270/1/140270.pdf Small, D. <http://eprints.gla.ac.uk/view/author/19797.html>, Benetti, S., Dove, D., Ballantyne, C. K., Fabel, D. <http://eprints.gla.ac.uk/view/author/5585.html> , Clark, C. D., Gheorghiu, D. M. <http://eprints.gla.ac.uk/view/author/4244.html> , Newall, J. and Xu, S. <http://eprints.gla.ac.uk/view/author/12708.html> (2017) Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka. Quaternary Science Reviews <http://eprints.gla.ac.uk/view/journal_volume/Quaternary_Science_Reviews.html>, 167, pp. 30-46. (doi:10.1016/j.quascirev.2017.04.021 <http://dx.doi.org/10.1016/j.quascirev.2017.04.021>) cc_by_4 CC-BY Articles PeerReviewed 2017 ftuglasgow https://doi.org/10.1016/j.quascirev.2017.04.021 2020-05-28T22:17:15Z Understanding how marine-based ice streams operated during episodes of deglaciation requires geochronological data that constrain both timing of deglaciation and changes in their flow behaviour, such as that from unconstrained ice streaming to topographically restricted flow. We present seventeen new 10Be exposure ages from glacial boulders and bedrock at sites in western Scotland within the area drained by the Hebrides Ice Stream, a marine-based ice stream that drained a large proportion of the former British-Irish Ice Sheet. Exposure ages from Tiree constrain deglaciation of a topographic high within the central zone of the ice stream, from which convergent flowsets were produced during ice streaming. These ages thus constrain thinning of the Hebrides Ice Stream, which, on the basis of supporting information, we infer to represent cessation of ice streaming at 20.6 ± 1.2 ka, 3–4 ka earlier than previously inferred. A period of more topographically restricted flow produced flow indicators superimposed on those relating to full ice stream conditions, and exposure ages from up-stream of these constrain deglaciation to 17.5 ± 1.0 ka. Complete deglaciation of the marine sector of the Hebrides Ice Stream occurred by 17–16 ka at which time the ice margin was located near the present coastline. Exposure ages from the southernmost Outer Hebrides (Mingulay and Barra) indicate deglaciation at 18.9 ± 1.0 and 17.1 ± 1.0 ka respectively, demonstrating that an independent ice cap persisted on the southern Outer Hebrides for 3–4 ka after initial ice stream deglaciation. This suggests that deglaciation of the Hebrides Ice Stream was focused along major submarine troughs. Collectively, our data constrain initial deglaciation and changes in flow regime of the Hebrides Ice Stream, final deglaciation of its marine sector, and deglaciation of the southern portion of the independent Outer Hebrides Ice Cap, providing chronological constraints on future numerical reconstructions of this key sector of the former British-Irish Ice Sheet. Article in Journal/Newspaper Ice cap Ice Sheet Ice Stream A University of Glasgow: Enlighten - Publications Barra ENVELOPE(-61.417,-61.417,-64.367,-64.367) Quaternary Science Reviews 167 30 46 |
institution |
Open Polar |
collection |
University of Glasgow: Enlighten - Publications |
op_collection_id |
ftuglasgow |
language |
English |
description |
Understanding how marine-based ice streams operated during episodes of deglaciation requires geochronological data that constrain both timing of deglaciation and changes in their flow behaviour, such as that from unconstrained ice streaming to topographically restricted flow. We present seventeen new 10Be exposure ages from glacial boulders and bedrock at sites in western Scotland within the area drained by the Hebrides Ice Stream, a marine-based ice stream that drained a large proportion of the former British-Irish Ice Sheet. Exposure ages from Tiree constrain deglaciation of a topographic high within the central zone of the ice stream, from which convergent flowsets were produced during ice streaming. These ages thus constrain thinning of the Hebrides Ice Stream, which, on the basis of supporting information, we infer to represent cessation of ice streaming at 20.6 ± 1.2 ka, 3–4 ka earlier than previously inferred. A period of more topographically restricted flow produced flow indicators superimposed on those relating to full ice stream conditions, and exposure ages from up-stream of these constrain deglaciation to 17.5 ± 1.0 ka. Complete deglaciation of the marine sector of the Hebrides Ice Stream occurred by 17–16 ka at which time the ice margin was located near the present coastline. Exposure ages from the southernmost Outer Hebrides (Mingulay and Barra) indicate deglaciation at 18.9 ± 1.0 and 17.1 ± 1.0 ka respectively, demonstrating that an independent ice cap persisted on the southern Outer Hebrides for 3–4 ka after initial ice stream deglaciation. This suggests that deglaciation of the Hebrides Ice Stream was focused along major submarine troughs. Collectively, our data constrain initial deglaciation and changes in flow regime of the Hebrides Ice Stream, final deglaciation of its marine sector, and deglaciation of the southern portion of the independent Outer Hebrides Ice Cap, providing chronological constraints on future numerical reconstructions of this key sector of the former British-Irish Ice Sheet. |
format |
Article in Journal/Newspaper |
author |
Small, David Benetti, Sara Dove, Dayton Ballantyne, Colin K. Fabel, Derek Clark, Chris D. Gheorghiu, Delia M. Newall, Jennifer Xu, Sheng |
spellingShingle |
Small, David Benetti, Sara Dove, Dayton Ballantyne, Colin K. Fabel, Derek Clark, Chris D. Gheorghiu, Delia M. Newall, Jennifer Xu, Sheng Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka |
author_facet |
Small, David Benetti, Sara Dove, Dayton Ballantyne, Colin K. Fabel, Derek Clark, Chris D. Gheorghiu, Delia M. Newall, Jennifer Xu, Sheng |
author_sort |
Small, David |
title |
Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka |
title_short |
Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka |
title_full |
Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka |
title_fullStr |
Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka |
title_full_unstemmed |
Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka |
title_sort |
cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western scotland, 21–16 ka |
publisher |
Elsevier |
publishDate |
2017 |
url |
http://eprints.gla.ac.uk/140270/ http://eprints.gla.ac.uk/140270/1/140270.pdf |
long_lat |
ENVELOPE(-61.417,-61.417,-64.367,-64.367) |
geographic |
Barra |
geographic_facet |
Barra |
genre |
Ice cap Ice Sheet Ice Stream A |
genre_facet |
Ice cap Ice Sheet Ice Stream A |
op_relation |
http://eprints.gla.ac.uk/140270/1/140270.pdf Small, D. <http://eprints.gla.ac.uk/view/author/19797.html>, Benetti, S., Dove, D., Ballantyne, C. K., Fabel, D. <http://eprints.gla.ac.uk/view/author/5585.html> , Clark, C. D., Gheorghiu, D. M. <http://eprints.gla.ac.uk/view/author/4244.html> , Newall, J. and Xu, S. <http://eprints.gla.ac.uk/view/author/12708.html> (2017) Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka. Quaternary Science Reviews <http://eprints.gla.ac.uk/view/journal_volume/Quaternary_Science_Reviews.html>, 167, pp. 30-46. (doi:10.1016/j.quascirev.2017.04.021 <http://dx.doi.org/10.1016/j.quascirev.2017.04.021>) |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.quascirev.2017.04.021 |
container_title |
Quaternary Science Reviews |
container_volume |
167 |
container_start_page |
30 |
op_container_end_page |
46 |
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1766028491284807680 |