Late Cenozoic evolution of the Ariège River valley (Pyrenees) constrained by cosmogenic 26Al/10Be and 10Be/21Ne dating of cave sediments
In: Geomorphology Geomorphology, Elsevier, In press, 371, pp.1-20. ⟨10.1016/j.geomorph.2020.107441⟩; (2020)
Online
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Zugriff:
International audience; Despite increasing knowledge on the orogenic phases of the Pyrenees, the Neogene evolution of the range remains poorly constrained. The central Pyrenees, particularly the Ariège River valley and its terrace systems and glacial extensions, are key to reconstructing Pyrenean evolution during the Neogene. However, few terrace relics remain on the piedmont edges. To overcome this limitation and temporally extend the dataset obtained from terraces, we focus on alluvium-filled horizontal epiphreatic passages developed in limestone karstic networks. These landforms record the transient position of former local base levels during the process of valley deepening, similar to fluvial terraces. The alluvium fills of the studied caves in the Tarascon-sur-Ariège area, in the transition zone between the upper range and the piedmont, therefore enable the reconstruction of the geodynamic evolution of the Ariège River valley. All studied caves are developed on at least eight levels. Based on burial durations determined by 26Al/10Be and 10Be/21Ne terrestrial cosmogenic nuclide dating of samples from epiphreatic levels, our results indicate Langhian to Messinian (~13–5 Ma) incision rates averaging 48 m Myr−1. However, the obtained record does not allow us to accurately retrace the Pliocene evolution of the area due to the lack of known caves at corresponding levels. Moreover, raised local base levels during glacial phases both make the record more complex and call into question the methodological approach in terms of potential internal sediment remobilization and mixing related to implied re-flooding periods.
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Late Cenozoic evolution of the Ariège River valley (Pyrenees) constrained by cosmogenic 26Al/10Be and 10Be/21Ne dating of cave sediments
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Autor/in / Beteiligte Person: | Sartégou, Amandine ; Blard, Pierre‐Henri ; BRAUCHER, Regis ; Bourlès, Didier ; Sorriaux, Patrick ; Zimmermann, Laurent ; Laffitte, Alexis ; Tibari, Bouchaïb ; Leanni, Laëtitia ; Guillou, Valéry ; Bourdet, Audry ; Aumaitre, Georges ; KEDDADOUCHE, Karim ; 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)-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)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) ; Centre de Recherches Pétrographiques et Géochimiques (CRPG) ; Université de Lorraine (UL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) ; Laboratoire de Glaciologie [Bruxelles] ; Université libre de Bruxelles (ULB) ; Géosciences Environnement Toulouse (GET) ; Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP) ; Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD) ; PyrénéesINSU, RGF |
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Quelle: | Geomorphology Geomorphology, Elsevier, In press, 371, pp.1-20. ⟨10.1016/j.geomorph.2020.107441⟩; (2020) |
Veröffentlichung: | HAL CCSD, 2020 |
Medientyp: | unknown |
ISSN: | 0169-555X (print) |
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