Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea
Geological constraints on ice-sheet deglaciation are essential for improving the modelling of ice masses and understanding their potential for future change. Here we present a detailed interpretation of depositional environments from a new 30-metre long borehole in the central North Sea, with the ai...
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ftnerc:oai:nora.nerc.ac.uk:10076 2023-05-15T16:13:07+02:00 Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea Graham, Alastair G.C. Lonergan, Lidia Stoker, Martyn S. 2010-07 http://nora.nerc.ac.uk/id/eprint/10076/ http://www3.interscience.wiley.com/journal/118902553/home unknown Wiley-Blackwell Graham, Alastair G.C.; Lonergan, Lidia; Stoker, Martyn S. 2010 Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea. Boreas, 39 (3). 471-491. https://doi.org/10.1111/j.1502-3885.2010.00144.x <https://doi.org/10.1111/j.1502-3885.2010.00144.x> Marine Sciences Earth Sciences Publication - Article PeerReviewed 2010 ftnerc https://doi.org/10.1111/j.1502-3885.2010.00144.x 2023-02-04T19:26:27Z Geological constraints on ice-sheet deglaciation are essential for improving the modelling of ice masses and understanding their potential for future change. Here we present a detailed interpretation of depositional environments from a new 30-metre long borehole in the central North Sea, with the aim of improving constraints on the history of the marine Late Pleistocene British–Fennoscandian Ice Sheet. Seven units characterise a sequence of compacted and distorted glaciomarine diamictons, which are overlain by interbedded glaciomarine diamictons and soft, bedded to homogeneous marine muds. Through correlation of borehole and 2D/3D seismic observations, we identify three palaeo-regimes. These are: a period of advance and ice-sheet overriding; a phase of deglaciation; and a phase of postglacial glaciomarine-to-marine sedimentation. Deformed subglacial sediments correlate with a buried suite of streamlined subglacial bedforms, and indicate overridding by the SE–NW-flowing Witch Ground ice-stream. AMS 14C dating confirms ice-stream activity and extensive glaciation of the North Sea during the Last Glacial Maximum, between c. 30 and 16.2 14C ka BP. Sediments overlying the ice-compacted deposits have been reworked, but can be used to constrain initial deglaciation to no later than 16.2 14C ka BP. A re-advance of British ice during the last deglaciation, dated at 13.9 14C ka BP, delivered ice-proximal deposits to the core site and deposited glaciomarine sediments rapidly during the subsequent retreat. A transition to more temperate marine conditions is clear in lithostratigraphic and seismic records, marked by a regionally-pervasive iceberg-ploughmarked erosion surface. The iceberg discharges that formed this horizon are dated to between 13.9 and 12 14C ka BP, and may correspond to oscillating ice-sheet margins during final, dynamic ice-sheet decay. Article in Journal/Newspaper Fennoscandian Ice Sheet Natural Environment Research Council: NERC Open Research Archive Boreas |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Marine Sciences Earth Sciences |
spellingShingle |
Marine Sciences Earth Sciences Graham, Alastair G.C. Lonergan, Lidia Stoker, Martyn S. Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea |
topic_facet |
Marine Sciences Earth Sciences |
description |
Geological constraints on ice-sheet deglaciation are essential for improving the modelling of ice masses and understanding their potential for future change. Here we present a detailed interpretation of depositional environments from a new 30-metre long borehole in the central North Sea, with the aim of improving constraints on the history of the marine Late Pleistocene British–Fennoscandian Ice Sheet. Seven units characterise a sequence of compacted and distorted glaciomarine diamictons, which are overlain by interbedded glaciomarine diamictons and soft, bedded to homogeneous marine muds. Through correlation of borehole and 2D/3D seismic observations, we identify three palaeo-regimes. These are: a period of advance and ice-sheet overriding; a phase of deglaciation; and a phase of postglacial glaciomarine-to-marine sedimentation. Deformed subglacial sediments correlate with a buried suite of streamlined subglacial bedforms, and indicate overridding by the SE–NW-flowing Witch Ground ice-stream. AMS 14C dating confirms ice-stream activity and extensive glaciation of the North Sea during the Last Glacial Maximum, between c. 30 and 16.2 14C ka BP. Sediments overlying the ice-compacted deposits have been reworked, but can be used to constrain initial deglaciation to no later than 16.2 14C ka BP. A re-advance of British ice during the last deglaciation, dated at 13.9 14C ka BP, delivered ice-proximal deposits to the core site and deposited glaciomarine sediments rapidly during the subsequent retreat. A transition to more temperate marine conditions is clear in lithostratigraphic and seismic records, marked by a regionally-pervasive iceberg-ploughmarked erosion surface. The iceberg discharges that formed this horizon are dated to between 13.9 and 12 14C ka BP, and may correspond to oscillating ice-sheet margins during final, dynamic ice-sheet decay. |
format |
Article in Journal/Newspaper |
author |
Graham, Alastair G.C. Lonergan, Lidia Stoker, Martyn S. |
author_facet |
Graham, Alastair G.C. Lonergan, Lidia Stoker, Martyn S. |
author_sort |
Graham, Alastair G.C. |
title |
Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea |
title_short |
Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea |
title_full |
Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea |
title_fullStr |
Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea |
title_full_unstemmed |
Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea |
title_sort |
depositional environments and chronology of late weichselian glaciation and deglaciation in the central north sea |
publisher |
Wiley-Blackwell |
publishDate |
2010 |
url |
http://nora.nerc.ac.uk/id/eprint/10076/ http://www3.interscience.wiley.com/journal/118902553/home |
genre |
Fennoscandian Ice Sheet |
genre_facet |
Fennoscandian Ice Sheet |
op_relation |
Graham, Alastair G.C.; Lonergan, Lidia; Stoker, Martyn S. 2010 Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea. Boreas, 39 (3). 471-491. https://doi.org/10.1111/j.1502-3885.2010.00144.x <https://doi.org/10.1111/j.1502-3885.2010.00144.x> |
op_doi |
https://doi.org/10.1111/j.1502-3885.2010.00144.x |
container_title |
Boreas |
_version_ |
1765998722029715456 |