Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees
International audience Cirques are emblematic landforms of alpine landscapes. The statistical distribution of cirque-floor elevations is used to infer glacial equilibrium-line altitude, and the age of their frontal moraines for reconstructing glacial chronologies. Very few studies, however, have sou...
Published in: | Geomorphology |
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2017
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Online Access: | https://hal-amu.archives-ouvertes.fr/hal-01420871 https://hal-amu.archives-ouvertes.fr/hal-01420871/document https://hal-amu.archives-ouvertes.fr/hal-01420871/file/Crest%26al-Geomorphology.pdf https://doi.org/10.1016/j.geomorph.2016.10.035 |
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ftunivlyon3:oai:HAL:hal-01420871v1 2023-06-18T03:41:07+02:00 Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees Crest, Y. Delmas, M Braucher, Regis Gunnell, Y. Calvet, M Team, A.S.T.E.R. Histoire naturelle de l'Homme préhistorique (HNHP) Muséum national d'Histoire naturelle (MNHN)-Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS) Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université Lumière - Lyon 2 (UL2) 2017 https://hal-amu.archives-ouvertes.fr/hal-01420871 https://hal-amu.archives-ouvertes.fr/hal-01420871/document https://hal-amu.archives-ouvertes.fr/hal-01420871/file/Crest%26al-Geomorphology.pdf https://doi.org/10.1016/j.geomorph.2016.10.035 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.geomorph.2016.10.035 hal-01420871 https://hal-amu.archives-ouvertes.fr/hal-01420871 https://hal-amu.archives-ouvertes.fr/hal-01420871/document https://hal-amu.archives-ouvertes.fr/hal-01420871/file/Crest%26al-Geomorphology.pdf doi:10.1016/j.geomorph.2016.10.035 info:eu-repo/semantics/OpenAccess ISSN: 0169-555X Geomorphology https://hal-amu.archives-ouvertes.fr/hal-01420871 Geomorphology, 2017, 278, pp.60 - 77. ⟨10.1016/j.geomorph.2016.10.035⟩ Buzzsaw Pyrenees Cosmogenic nuclide dating Denudation rate Cirque [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2017 ftunivlyon3 https://doi.org/10.1016/j.geomorph.2016.10.035 2023-06-06T22:54:28Z International audience Cirques are emblematic landforms of alpine landscapes. The statistical distribution of cirque-floor elevations is used to infer glacial equilibrium-line altitude, and the age of their frontal moraines for reconstructing glacial chronologies. Very few studies, however, have sought to measure cirque-floor and supraglacial ridgetop bedrock downwearing rates in order to confront these denudation estimates with theoretical models of Quaternary mountain landscape evolution. Here we use 10 Be nuclide samples (n = 36) from moraines, bedrock steps, and supraglacial ridgetops among a population of cirques in the east-central Pyrenees in order to quantify denudation in the landscape and detect whether the mountain topography bears any relevance to the glacial buzzsaw hypothesis. Minimum exposure ages (MEAs) obtained for a succession of moraines spanning the Oldest Dryas to the Holocene produced a deglaciation chronology for three different Pyrenean ranges: Maladeta, Bassiès, and Carlit. Based on a series of corrections, calibrations, and chronostratigraphic tuning procedures, MEAs on ice-polished bedrock exposures were further used to model denudation depths at nested timescales during the Würm, the Younger Dryas, and the Holocene. Results show that subglacial cirque-floor denudation was lower during glacial periods (Würm: ~10 mm/ka) than during deglacial and interglacial periods (tens to hundreds of mm/ka). The relative inefficiency of glacial denudation in the cirque zone during the Würm would have resulted from (i) cold-based and/or (ii) low-gradient glaciers situated in the upper reaches of the icefield; and/or from (iii) glacier-load starvation because of arrested clast supply from supraglacial rockslopes situated in the permafrost zone. Denudation peaked during the Younger Dryas and Holocene glacial advances, a time when cirque glaciers became steeper, warmer-based, and when frost cracking weakened supraglacial ridgetops, thus enhancing sub-glacial erosion by providing debris to the sliding ... Article in Journal/Newspaper Ice permafrost Université Jean Moulin - Lyon 3: Publications scientifiques (HAL) Geomorphology 278 60 77 |
institution |
Open Polar |
collection |
Université Jean Moulin - Lyon 3: Publications scientifiques (HAL) |
op_collection_id |
ftunivlyon3 |
language |
English |
topic |
Buzzsaw Pyrenees Cosmogenic nuclide dating Denudation rate Cirque [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
Buzzsaw Pyrenees Cosmogenic nuclide dating Denudation rate Cirque [SDE.MCG]Environmental Sciences/Global Changes Crest, Y. Delmas, M Braucher, Regis Gunnell, Y. Calvet, M Team, A.S.T.E.R. Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees |
topic_facet |
Buzzsaw Pyrenees Cosmogenic nuclide dating Denudation rate Cirque [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience Cirques are emblematic landforms of alpine landscapes. The statistical distribution of cirque-floor elevations is used to infer glacial equilibrium-line altitude, and the age of their frontal moraines for reconstructing glacial chronologies. Very few studies, however, have sought to measure cirque-floor and supraglacial ridgetop bedrock downwearing rates in order to confront these denudation estimates with theoretical models of Quaternary mountain landscape evolution. Here we use 10 Be nuclide samples (n = 36) from moraines, bedrock steps, and supraglacial ridgetops among a population of cirques in the east-central Pyrenees in order to quantify denudation in the landscape and detect whether the mountain topography bears any relevance to the glacial buzzsaw hypothesis. Minimum exposure ages (MEAs) obtained for a succession of moraines spanning the Oldest Dryas to the Holocene produced a deglaciation chronology for three different Pyrenean ranges: Maladeta, Bassiès, and Carlit. Based on a series of corrections, calibrations, and chronostratigraphic tuning procedures, MEAs on ice-polished bedrock exposures were further used to model denudation depths at nested timescales during the Würm, the Younger Dryas, and the Holocene. Results show that subglacial cirque-floor denudation was lower during glacial periods (Würm: ~10 mm/ka) than during deglacial and interglacial periods (tens to hundreds of mm/ka). The relative inefficiency of glacial denudation in the cirque zone during the Würm would have resulted from (i) cold-based and/or (ii) low-gradient glaciers situated in the upper reaches of the icefield; and/or from (iii) glacier-load starvation because of arrested clast supply from supraglacial rockslopes situated in the permafrost zone. Denudation peaked during the Younger Dryas and Holocene glacial advances, a time when cirque glaciers became steeper, warmer-based, and when frost cracking weakened supraglacial ridgetops, thus enhancing sub-glacial erosion by providing debris to the sliding ... |
author2 |
Histoire naturelle de l'Homme préhistorique (HNHP) Muséum national d'Histoire naturelle (MNHN)-Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS) Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Université Lumière - Lyon 2 (UL2) |
format |
Article in Journal/Newspaper |
author |
Crest, Y. Delmas, M Braucher, Regis Gunnell, Y. Calvet, M Team, A.S.T.E.R. |
author_facet |
Crest, Y. Delmas, M Braucher, Regis Gunnell, Y. Calvet, M Team, A.S.T.E.R. |
author_sort |
Crest, Y. |
title |
Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees |
title_short |
Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees |
title_full |
Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees |
title_fullStr |
Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees |
title_full_unstemmed |
Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees |
title_sort |
cirques have growth spurts during deglacial and interglacial periods: evidence from 10be and 26al nuclide inventories in the central and eastern pyrenees |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://hal-amu.archives-ouvertes.fr/hal-01420871 https://hal-amu.archives-ouvertes.fr/hal-01420871/document https://hal-amu.archives-ouvertes.fr/hal-01420871/file/Crest%26al-Geomorphology.pdf https://doi.org/10.1016/j.geomorph.2016.10.035 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
ISSN: 0169-555X Geomorphology https://hal-amu.archives-ouvertes.fr/hal-01420871 Geomorphology, 2017, 278, pp.60 - 77. ⟨10.1016/j.geomorph.2016.10.035⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.geomorph.2016.10.035 hal-01420871 https://hal-amu.archives-ouvertes.fr/hal-01420871 https://hal-amu.archives-ouvertes.fr/hal-01420871/document https://hal-amu.archives-ouvertes.fr/hal-01420871/file/Crest%26al-Geomorphology.pdf doi:10.1016/j.geomorph.2016.10.035 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1016/j.geomorph.2016.10.035 |
container_title |
Geomorphology |
container_volume |
278 |
container_start_page |
60 |
op_container_end_page |
77 |
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1769006558139645952 |