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

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.

First high resolution chronostratigraphy for the early North African Acheulean at Casablanca (Morocco).

The onset of the Acheulean, marked by the emergence of large cutting tools (LCTs), is considered a major technological advance in the Early Stone Age and a key turning point in human evolution. The Acheulean originated in East Africa at ~ 1.8-1.6 Ma and is reported in South Africa between ~ 1.6 and > 1.0 Ma. The timing of its appearance and development in North Africa have been poorly known due to the near-absence of well-dated sites in reliable contexts. The ~ 1 Ma stone artefacts of Tighennif (Algeria) and Thomas Quarry I-Unit L (ThI-L) at Casablanca (Morocco) are thus far regarded as documenting the oldest Acheulean in North Africa but whatever the precision of their stratigraphical position, both deserve a better chronology. Here we provide a chronology for ThI-L, based on new magnetostratigraphic and geochemical data. Added to the existing lithostratigraphy of the Casablanca sequence, these results provide the first robust chronostratigraphic framework for the early North African Acheulean and firmly establish its emergence in this part of the continent back at least to ~ 1.3 Ma.