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

Rosalia Gallotti,Abderrahim Mohib,Jean-Philippe Degeai,Valérie Andrieu-Ponel,Serena Perini,Jean-Paul Raynal,Denis Geraads,David Lefèvre,Séverine Sanz-Laliberté,Mohssine El Graoui,Paul Fernandes,Matteo Maron,Camille Daujeard,Giovanni Muttoni,Mathieu Rué,Lionel Magoga,Andrea Zerboni

doi:10.1038/s41598-021-94695-3

Abstract

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.

Highlights

Over the last two decades, several efforts have been made to refine the chronostratigraphic framework of the Acheulean emergence in Africa
Thomas Quarry I is in the south-western suburbs of Casablanca (Fig. 1) and exposes an Early–Middle Pleistocene stratigraphic sequence
Raised marine platforms that can be assigned to the late Early to the Late Pleistocene. They revealed a rich complex of archaeological sites (Fig. 2A): the Oulad Hamida Formation (OHF, late Early Pleistocene-early Middle Pleistocene), the Anfa (AF) and Kef Haroun Formations (Middle Pleistocene), and the Dar Bou Azza Formation (Late Pleistocene)[9,10]

Summary

Introduction

Over the last two decades, several efforts have been made to refine the chronostratigraphic framework of the Acheulean emergence in Africa. As regards the Early Pleistocene, the only North African Acheulean sites in known stratigraphic context are Tighennif near Mascara in Algeria and Thomas Quarry I (ThI) in Morocco[7,8] (Fig. 1). Thomas Quarry I is in the south-western suburbs of Casablanca (Fig. 1) and exposes an Early–Middle Pleistocene stratigraphic sequence. In this area, four formations including several members are associated with four. Lithostratigraphy, biostratigraphy, and OSL ages placed ThI-L at approximately 1 Ma, an age similar to that of Tighennif, the chronology of these two sites remained poorly d efined[8,12,13] as was the age of emergence of the Acheulean and its subsequent development in this part of the African continent. We present new chronostratigraphic data based on magnetostratigraphy and geochemistry for ThI-L, which constrain its age and provide a robust high-resolution framework for the earliest Acheulean in North Africa, pushing the time of its first appearance in this part of the continent back at least to ~ 1.3 Ma

Methods

Findings

Conclusion