Binge/purge oscillations during the deglacial decay of the Scandinavian Ice Sheet revealed by εNd and biomarkers
1 : Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement
(CEREGE)
Aix-Marseille Univ, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, CNRS, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, IRD, CEREGE, UMR 161, 13545 Aix en Provence cedex 4, France, Collège de France, CEREGE, 13545 Aix en Provence cedex 4, France
Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence Cedex 04, France -
France
2 : Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement
(CEREGE)
Aix-Marseille Univ, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, CNRS, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, IRD, CEREGE, UMR 161, 13545 Aix en Provence cedex 4, France, Collège de France, CEREGE, 13545 Aix en Provence cedex 4, France
Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence Cedex 04, France -
France
3 : IFREMER
(IFREMER)
IFREMER
Ifremer Centre de Recherche Halieutique Méditerranéen et Tropical, B.P. 171, Av. Jean Monnet, 34203 Sète Cedex , France -
France
4 : Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement
(CEREGE)
Aix-Marseille Univ, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, CNRS, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, IRD, CEREGE, UMR 161, 13545 Aix en Provence cedex 4, France, Collège de France, CEREGE, 13545 Aix en Provence cedex 4, France
Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence Cedex 04, France -
France
5 : IFREMER
(IFREMER)
IFREMER
Ifremer Centre de Recherche Halieutique Méditerranéen et Tropical, B.P. 171, Av. Jean Monnet, 34203 Sète Cedex , France -
France
6 : IFREMER
(IFREMER)
IFREMER
Ifremer Centre de Recherche Halieutique Méditerranéen et Tropical, B.P. 171, Av. Jean Monnet, 34203 Sète Cedex , France -
France
7 : Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement
(CEREGE)
Aix-Marseille Univ, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, CNRS, CEREGE, UMR 6635, 13545 Aix en Provence cedex 4, France, IRD, CEREGE, UMR 161, 13545 Aix en Provence cedex 4, France, Collège de France, CEREGE, 13545 Aix en Provence cedex 4, France
Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence Cedex 04, France -
France
At its maximum extent, the Scandinavian Ice Sheet advanced into the watershed of the Dnepr River, one of the main rivers feeding the former Black Sea “Lake”. As a consequence, the Black Sea basin potentially represents a suitable location to investigate the dynamics of the decaying FIS and its impacts on global/regional climate and European hydrographical reorganizations in the context of the Last Deglaciation. Here, we report high-resolution geochemical data from a core retrieved in the Black Sea. We combine the use of Nd isotopes in clay fraction (εNd) and bulk XRF-Ti/Ca as tracers for sediment provenance, together with biomarkers as tracers for river runoff (BIT-index) and boreal soil leaching (C25-alkanes). During Heinrich Event 1 (HE1), four periods of drastic increase in runoff (Deglacial Water Pulses; DWP) occurred as unequivocally revealed by the biomarkers. Concomitantly, εNd signatures clearly demonstrated that the DWPs were generated by the decaying FIS. Each period of DWPs (~200 yr in duration) occurred repeatedly every 200 yr, displaying a peculiar cyclic-like pattern. We invoke binge-purge oscillations of the FIS to explain the observed cyclicity: the binge period requiring a continuous FIS retreat, the purge period involving an ice sheet re-advance linked to some interactions between the FIS, the proglacial lakes and the atmosphere.
| Subject : | : | talk |
| Topics | : | Sessions générales |
| PDF version | : |  PDF version |
