1. Glacial oscillations during the Bølling–Allerød Interstadial–Younger Dryas transition in the Ruda Valley, Central Pyrenees
- Author
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Irene Schimmelpfennig, Maria Rosário Fernandes, David Palacios, Julia García-Oteyza, Marc Oliva, Gonçalo Vieira, Dermot Antoniades, Aster Team, José M. Fernández-Fernández, Repositório da Universidade de Lisboa, Universidade de Lisboa = University of Lisbon (ULISBOA), Universitat de Barcelona (UB), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), 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), and Université Laval [Québec] (ULaval)
- Subjects
Younger Dryas ,010504 meteorology & atmospheric sciences ,Bølling–Allerød ,010502 geochemistry & geophysics ,01 natural sciences ,Paleontology ,Bølling-Allerød ,Arts and Humanities (miscellaneous) ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,Cosmic‐ray exposure dating ,Earth and Planetary Sciences (miscellaneous) ,Deglaciation ,[SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology ,[SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology ,Glacial period ,Stadial ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Cosmic-Ray Exposure dating ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,Central Pyrenees ,Geology - Abstract
International audience; The Upper Garonne Basin included the largest glacial system in the Pyrenees during the last glacial cycle. Within the long-term glacial retreat during Termination-1 (T-1), glacier fluctuations left geomorphic evidence in the area. However, the chronology of T-1 glacial oscillations on the northern slope of the Central Pyrenees is still poorly constrained. Here, we introduce new geomorphological observations and a 12-sample dataset of 10Be Cosmic-Ray Exposure (CRE) ages from the Ruda Valley. This U-shaped valley, surrounded by peaks exceeding 2800 m a.s.l., includes a sequence of moraines and polished surfaces that enabled to reconstruct the chronology of the last deglaciation. Following the maximum ice extent, warmer conditions prevailing at ~15-14 ka, during the Bølling-Allerød (B-A) Interstadial, favoured glacial retreat in the Ruda Valley. Within the B-A, glaciers experienced two phases of advance/stillstand with moraine formation at 13.5 and 13.0 ka. During the early YD, glacial retreat exposed the highest surfaces of the Saboredo Cirque (~2300-2350 m) at 12.7 ka. Small glaciers persisted only inside the highest cirques (~2470 m), such as in Sendrosa Cirque, with moraines stabilizing at 12.6 ka. The results of this work present the most complete chronology for Pyrenean glacial oscillations from the B-A to the YD.
- Published
- 2021