Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms
The Central Pyrenees hosted a large ice cap during the Late Pleistocene. The cirques under relatively low-altitude peaks (2200-2800 m) include the greatest variety of glacial landforms (moraines, fossil debris-covered glaciers and rock glaciers), but their age and formation process are poorly known....
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Language: | English |
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Elsevier B.V.
2021
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Online Access: | http://hdl.handle.net/2445/184866 |
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ftubarcepubl:oai:diposit.ub.edu:2445/184866 2024-02-11T10:04:45+01:00 Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms Oliva Franganillo, Marc Fernandes, M. Palacios, D. Fernández-Fernández, J-M. Schimmelpfennig, I. Antoniades, D. ASTER Team 2021 18 p. application/pdf http://hdl.handle.net/2445/184866 eng eng Elsevier B.V. Reproducció del document publicat a: https://doi.org/10.1016/j.geomorph.2021.107735 Geomorphology, 2021, num. 385, p. 1-18 Articles publicats en revistes (Geografia) https://doi.org/10.1016/j.geomorph.2021.107735 0169-555X http://hdl.handle.net/2445/184866 713689 cc-by (c) Oliva Franganillo, Marc et al., 2021 http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Glaceres Geomorfologia glacial Pirineus Glaciers Glacial landforms Pyrenees info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftubarcepubl https://doi.org/10.1016/j.geomorph.2021.107735 2024-01-24T01:17:27Z The Central Pyrenees hosted a large ice cap during the Late Pleistocene. The cirques under relatively low-altitude peaks (2200-2800 m) include the greatest variety of glacial landforms (moraines, fossil debris-covered glaciers and rock glaciers), but their age and formation process are poorly known. Here, we focus on the headwaters of the Garonne River, namely on the low-altitude Bacivèr Cirque (highest peaks at ~2600 m), with widespread erosive and depositional glacial and periglacial landforms. We reconstruct the pattern of deglaciation from geomorphological observations and a 17-sample dataset of 10Be Cosmic-Ray Exposure (CRE) ages. Ice thickness in the Bacivèr Cirque must have reached ~200 m during the maximum ice extent of the last glacial cycle, when it flowed down towards the Garonne paleoglacier. However, by ~15 ka, during the Bølling-Allerød (B-A) Interstadial, the mouth of the cirque was deglaciated as the tributary glacier shrank and disconnected from the Garonne paleoglacier. Glacial retreat was rapid, and the whole cirque was likely to have been deglaciated in only a few centuries, while paraglacial processes accelerated, leading to the transformation of debris-free glaciers into debriscovered and rock glaciers in their final stages. Climate conditions prevailing at the transition between the B-A and the Younger Dryas (YD) favored glacial growth and the likely development of small moraines within the slopes of the cirque walls by ~12.9 ka, but the dating uncertainties make it impossible to state whether these moraines formed during the B-A or the YD. The melting of these glaciers favored paraglacial dynamics, which promoted the development of rock glaciers as well as debris-covered glaciers. These remained active throughout the Early Holocene until at least ~7 ka. Since then, the landscape of the Bacivèr Cirque has seen a period of relative stability. A similar chronological sequence of deglaciation has been also detected in other cirques of the Pyrenees below 3000 m. As in other mid-latitude ... Article in Journal/Newspaper Ice cap Dipòsit Digital de la Universitat de Barcelona Geomorphology 385 107735 |
institution |
Open Polar |
collection |
Dipòsit Digital de la Universitat de Barcelona |
op_collection_id |
ftubarcepubl |
language |
English |
topic |
Glaceres Geomorfologia glacial Pirineus Glaciers Glacial landforms Pyrenees |
spellingShingle |
Glaceres Geomorfologia glacial Pirineus Glaciers Glacial landforms Pyrenees Oliva Franganillo, Marc Fernandes, M. Palacios, D. Fernández-Fernández, J-M. Schimmelpfennig, I. Antoniades, D. ASTER Team Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms |
topic_facet |
Glaceres Geomorfologia glacial Pirineus Glaciers Glacial landforms Pyrenees |
description |
The Central Pyrenees hosted a large ice cap during the Late Pleistocene. The cirques under relatively low-altitude peaks (2200-2800 m) include the greatest variety of glacial landforms (moraines, fossil debris-covered glaciers and rock glaciers), but their age and formation process are poorly known. Here, we focus on the headwaters of the Garonne River, namely on the low-altitude Bacivèr Cirque (highest peaks at ~2600 m), with widespread erosive and depositional glacial and periglacial landforms. We reconstruct the pattern of deglaciation from geomorphological observations and a 17-sample dataset of 10Be Cosmic-Ray Exposure (CRE) ages. Ice thickness in the Bacivèr Cirque must have reached ~200 m during the maximum ice extent of the last glacial cycle, when it flowed down towards the Garonne paleoglacier. However, by ~15 ka, during the Bølling-Allerød (B-A) Interstadial, the mouth of the cirque was deglaciated as the tributary glacier shrank and disconnected from the Garonne paleoglacier. Glacial retreat was rapid, and the whole cirque was likely to have been deglaciated in only a few centuries, while paraglacial processes accelerated, leading to the transformation of debris-free glaciers into debriscovered and rock glaciers in their final stages. Climate conditions prevailing at the transition between the B-A and the Younger Dryas (YD) favored glacial growth and the likely development of small moraines within the slopes of the cirque walls by ~12.9 ka, but the dating uncertainties make it impossible to state whether these moraines formed during the B-A or the YD. The melting of these glaciers favored paraglacial dynamics, which promoted the development of rock glaciers as well as debris-covered glaciers. These remained active throughout the Early Holocene until at least ~7 ka. Since then, the landscape of the Bacivèr Cirque has seen a period of relative stability. A similar chronological sequence of deglaciation has been also detected in other cirques of the Pyrenees below 3000 m. As in other mid-latitude ... |
format |
Article in Journal/Newspaper |
author |
Oliva Franganillo, Marc Fernandes, M. Palacios, D. Fernández-Fernández, J-M. Schimmelpfennig, I. Antoniades, D. ASTER Team |
author_facet |
Oliva Franganillo, Marc Fernandes, M. Palacios, D. Fernández-Fernández, J-M. Schimmelpfennig, I. Antoniades, D. ASTER Team |
author_sort |
Oliva Franganillo, Marc |
title |
Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms |
title_short |
Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms |
title_full |
Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms |
title_fullStr |
Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms |
title_full_unstemmed |
Rapid deglaciation during the Bølling-Allerød Interstadial in the Central Pyrenees and associated glacial and periglacial landforms |
title_sort |
rapid deglaciation during the bølling-allerød interstadial in the central pyrenees and associated glacial and periglacial landforms |
publisher |
Elsevier B.V. |
publishDate |
2021 |
url |
http://hdl.handle.net/2445/184866 |
genre |
Ice cap |
genre_facet |
Ice cap |
op_relation |
Reproducció del document publicat a: https://doi.org/10.1016/j.geomorph.2021.107735 Geomorphology, 2021, num. 385, p. 1-18 Articles publicats en revistes (Geografia) https://doi.org/10.1016/j.geomorph.2021.107735 0169-555X http://hdl.handle.net/2445/184866 713689 |
op_rights |
cc-by (c) Oliva Franganillo, Marc et al., 2021 http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.geomorph.2021.107735 |
container_title |
Geomorphology |
container_volume |
385 |
container_start_page |
107735 |
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1790601477174067200 |