Depositional Environments and Chronology of Late Weichselian Glaciation and Deglaciation in the Central North Sea
Graham, A.G.C., Lonergan, L. & Stoker, M.S. 2010: Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea. Boreas, Vol. 39, pp. 471–491. 10.1111/j.1502-3885.2010.00144.x. ISSN 0300-9483. Geological constraints on ice-sheet deglaciation ar...
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ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2571 2023-05-15T16:13:09+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. 2010-01-01T08:00:00Z https://digitalcommons.usf.edu/msc_facpub/1540 https://doi.org/10.1111/j.1502-3885.2010.00144.x unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1540 https://doi.org/10.1111/j.1502-3885.2010.00144.x Marine Science Faculty Publications Life Sciences article 2010 ftunisfloridatam https://doi.org/10.1111/j.1502-3885.2010.00144.x 2022-01-20T18:39:31Z Graham, A.G.C., Lonergan, L. & Stoker, M.S. 2010: Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea. Boreas, Vol. 39, pp. 471–491. 10.1111/j.1502-3885.2010.00144.x. ISSN 0300-9483. 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-m-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 characterize 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 palaeoregimes. 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 overriding 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 Digital Commons University of South Florida (USF) Boreas ENVELOPE(-3.933,-3.933,-71.300,-71.300) Boreas |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
Life Sciences |
spellingShingle |
Life 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 |
Life Sciences |
description |
Graham, A.G.C., Lonergan, L. & Stoker, M.S. 2010: Depositional environments and chronology of Late Weichselian glaciation and deglaciation in the central North Sea. Boreas, Vol. 39, pp. 471–491. 10.1111/j.1502-3885.2010.00144.x. ISSN 0300-9483. 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-m-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 characterize 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 palaeoregimes. 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 overriding 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 |
Digital Commons @ University of South Florida |
publishDate |
2010 |
url |
https://digitalcommons.usf.edu/msc_facpub/1540 https://doi.org/10.1111/j.1502-3885.2010.00144.x |
long_lat |
ENVELOPE(-3.933,-3.933,-71.300,-71.300) |
geographic |
Boreas |
geographic_facet |
Boreas |
genre |
Fennoscandian Ice Sheet |
genre_facet |
Fennoscandian Ice Sheet |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1540 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_ |
1765998763015405568 |