Cosmogenic exposure age constraints on deglaciation and flow behaviour of a marine-based ice stream in western Scotland, 21–16 ka
This work was supported by the Natural Environment Research Council consortium grant; BRITICE-CHRONO (NE/J009768/1). Analysis was supported by the NERC Cosmogenic Isotope Analysis Facility allocations 9139.1013 and 9155.1014. Understanding how marine-based ice streams operated during episodes of deg...
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ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/10720 2024-04-28T08:24:01+00:00 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 University of St Andrews. School of Geography and Geosciences University of St Andrews. Geography & Sustainable Development 2017-05-08T09:30:15Z 17 9218562 application/pdf https://hdl.handle.net/10023/10720 https://doi.org/10.1016/j.quascirev.2017.04.021 eng eng Quaternary Science Reviews 249950496 68429e76-7248-4ce1-aba7-474ad3a79033 85018730249 000403997900003 Small , D , Benetti , S , Dove , D , Ballantyne , C K , Fabel , D , Clark , C D , Gheorghiu , D M , Newall , J & Xu , S 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 , vol. 167 , pp. 30-46 . https://doi.org/10.1016/j.quascirev.2017.04.021 0277-3791 RIS: urn:D757CDC230D7FA9C90015B65F430DF15 https://hdl.handle.net/10023/10720 doi:10.1016/j.quascirev.2017.04.021 Exposure dating Marine ice stream British-Irish ice sheet Deglaciation GE Environmental Sciences QE Geology NDAS SDG 14 - Life Below Water GE QE Journal article 2017 ftstandrewserep https://doi.org/10.1016/j.quascirev.2017.04.021 2024-04-03T14:07:22Z This work was supported by the Natural Environment Research Council consortium grant; BRITICE-CHRONO (NE/J009768/1). Analysis was supported by the NERC Cosmogenic Isotope Analysis Facility allocations 9139.1013 and 9155.1014. 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 ... Article in Journal/Newspaper Ice cap Ice Sheet Ice Stream A University of St Andrews: Digital Research Repository Quaternary Science Reviews 167 30 46 |
institution |
Open Polar |
collection |
University of St Andrews: Digital Research Repository |
op_collection_id |
ftstandrewserep |
language |
English |
topic |
Exposure dating Marine ice stream British-Irish ice sheet Deglaciation GE Environmental Sciences QE Geology NDAS SDG 14 - Life Below Water GE QE |
spellingShingle |
Exposure dating Marine ice stream British-Irish ice sheet Deglaciation GE Environmental Sciences QE Geology NDAS SDG 14 - Life Below Water GE QE 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 |
topic_facet |
Exposure dating Marine ice stream British-Irish ice sheet Deglaciation GE Environmental Sciences QE Geology NDAS SDG 14 - Life Below Water GE QE |
description |
This work was supported by the Natural Environment Research Council consortium grant; BRITICE-CHRONO (NE/J009768/1). Analysis was supported by the NERC Cosmogenic Isotope Analysis Facility allocations 9139.1013 and 9155.1014. 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 ... |
author2 |
University of St Andrews. School of Geography and Geosciences University of St Andrews. Geography & Sustainable Development |
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 |
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 |
publishDate |
2017 |
url |
https://hdl.handle.net/10023/10720 https://doi.org/10.1016/j.quascirev.2017.04.021 |
genre |
Ice cap Ice Sheet Ice Stream A |
genre_facet |
Ice cap Ice Sheet Ice Stream A |
op_relation |
Quaternary Science Reviews 249950496 68429e76-7248-4ce1-aba7-474ad3a79033 85018730249 000403997900003 Small , D , Benetti , S , Dove , D , Ballantyne , C K , Fabel , D , Clark , C D , Gheorghiu , D M , Newall , J & Xu , S 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 , vol. 167 , pp. 30-46 . https://doi.org/10.1016/j.quascirev.2017.04.021 0277-3791 RIS: urn:D757CDC230D7FA9C90015B65F430DF15 https://hdl.handle.net/10023/10720 doi:10.1016/j.quascirev.2017.04.021 |
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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