First fluvial archive of the 8.2 and 7.6–7.3 ka events in North Africa (Charef River, High Plateaus, NE Morocco)

Bruno Depreux (1, 2) , Jean-François Berger (3) , David Lefèvre (1, 2) , Quentin Wackenheim (4, 5) , Valérie Andrieu-Ponel (6, 7) , Sylvia Vinai (2) , Jean‑philippe Degeai (1, 2) , Abderrahmane El Harradji (8) , Larbi Boudad (9) , Séverine Sanz Laliberté (1, 2) , Kristell Michel (3) , Nicole Limondin-Lozouet (4)

1 ASM - Archéologie des Sociétés Méditerranéennes
2 LabEx ARCHIMEDE
3 EVS - Environnement, Ville, Société
4 LGP - Laboratoire de géographie physique : Environnements Quaternaires et Actuels
5 Trajectoires - UMR 8215
6 IMBE - Institut méditerranéen de biodiversité et d'écologie marine et continentale
7 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
8 University of Mohammed I - Université Mohammed Premier
9 UM5 - Université Mohammed V de Rabat [Agdal]

The Early–Mid Holocene transition is a period of profound changes in climatic mechanisms and hydrological features in Europe and North Africa. The melting of the Laurentide ice sheet led to an oceanic and atmospheric reorganisation in the North Atlantic, while the Mediterranean underwent a major hydrological shift. The impacts on Mediterranean rivers remain unclear, as there are few records documenting responses to the 8.2 ka event (the main Holocene climatic degradation). We present a fluvial record from Eastern Morocco documenting detailed hydrological variations from 8200 to 7500 cal. BP and their climatic forcing. A major hydrogeomorphic evolution of the Charef River occurred at that time, marked by two major incision stages close in time, under hyper-arid conditions at 8200 and ca. 7500 cal. BP. The impacts of these phenomena on the alluvial plains and associated archaeological records during Neolithisation, a major process in human history, currently remain unidentified. This new record sheds light on the fluvial response to the 8.2 ka event in North Africa and why other records are missing. We also bring new insights into the hydrological disruption at the Early–Mid Holocene transition, which was driven by the end of deglaciation combined with insolation and solar forcing. Furthermore, centennial solar variability may have paced river activity in the Moulouya basin and arid regions of North Africa

Domaines: Sciences de l'environnement

Bruno Depreux, Jean-François Berger, David Lefèvre, Quentin Wackenheim, Valérie Andrieu-Ponel, et al.. First fluvial archive of the 8.2 and 7.6–7.3 ka events in North Africa (Charef River, High Plateaus, NE Morocco). Scientific Reports, 2022, 12, pp.7710. ⟨10.1038/s41598-022-11353-y⟩. ⟨hal-03670310⟩