The western quest, first and second regional Acheuleans at Thomas-Oulad Hamida Quarries (Casablanca, Morocco)

In the Mio-Plio-Pleistocene sequence of Casablanca which covers the last six millions years, the oldest lithic assemblages are found in late Lower Pleistocene deposits, circa 1 Ma, in unit L of Thomas Quarry I, and consist of artefacts made from quartzite and flint. They document the First Regional Acheulean (FRA). More recent units from Thomas - Oulad Hamida and Sidi Abderrahmane Quarries yielded numerous remains of Homo heidelbergensis/ rhodesiensis and lithic techno-complexes which characterize the Second Regional Acheulean (SRA) variability. This bi-partition of the Regional Acheuleans offers useful data for comparison with other areas of Africa and Middle East where hominids appeared and developed and should be considered in the debate about the earliest occupations of Europe.

The Maghreb is rich in testimonies of ancient populations. Numerous works carried out in Morocco since the beginning of the last century have yielded highly significant results about Quaternary stratigraphy and Prehistory, Palaeontology and Paleoanthropology as well (see Biberson, 1961a and b). However, many questions concerning the very first peopling of the extreme Northwest of Africa still remain unanswered. If an old human presence is indisputable and if we can assume that it could be even older, we still ignore how and when hominins came and which route they followed. Most of the propositions on this topic remains widely speculative.

The Casablanca coast has been slowly uplifting since the end of the Miocene and a huge piling of marine and continental formations has preserved an exceptional record (Fig. 1). The Casablanca long sequence begins nearly 6 Ma ago in the Upper Miocene and spreads over the Plio-Quaternary times with an extremely detailed registration of the global climatic cycles (Biberson 1961a; Stearns 1978; Raynal et al. 1995, 1999; Lefèvre 2000; Lefèvre and Raynal 2002).

In the upper Early and Middle Pleistocene portion of this late sequence, controlled excavations were performed in the archaeological sites of Sidi Abderrahmane and mainly Thomas-Oulad Hamida Quarries within the France-Morocco cooperative program Casablanca associating the French archaeological “Mission littoral” (Ministère des Affaires Etrangères et du Développement International) and the Moroccan National Institute of Archaeology and Heritage Sciences (Ministry of Culture). They have yielded rich lithic assemblages that represent the only North Africa First Acheulean recorded in an undisputable stratigraphic context (Raynal and Texier, 1989; Raynal et al. 2001). In previous papers, we used, without a great conviction, a classical subdivision of the regional Acheulean in three stages, i.e. lower, middle and upper Acheulean. We prefer here to consider two groups on stratigraphic and chronologic basis : First Regional Acheulean (FRA) and Second Regional Acheulean (SRA) (Raynal et al. in press). When necessary, we will refer to the different units of the New Casablanca Lithostratigraphic Scale (NCLS) which synthetize all observations and interpretations (Texier et al., 1994, 2002; Lefèvre, 2000; Lefèvre and Raynal op cit) (Fig. 5).

In the introduction, we will briefly question the supposedly pre-Acheulean artefacts in Western Morocco and then present the key-sites for FRA and SRA at Casablanca.