The lower-middle palaeolithic transition in Western France: The example of layer 4 of the Menez-Dregan I site (Plouhinec, Finistere)

摘要

Menez-Dregan I is a Lower Palaeolithic site, situated at Plouhinec, Finistère, in Brittany. It is an ancient marine cave whose roof has gradually collapsed. Layer 4 from the site of Menez-Dregan I is the last occupation of this deposit, at a turning point between the Lower and Middle Palaeolithic. Geological correlations (Laforge & Monnier, 2011; Monnier & Hallegou?t, 2003) tend to place layer 4 in OIS 9 or 11, although no direct dating is yet available for this layer. This study focuses on the lithic industry from the 1991-2004 excavations and was undertaken in order to capture the various types of technical behaviour that could translate this transition. We present the lithic industry of this layer, which simultaneously combines 'archaic' characteristics, such as large quantities of pebbles, or the appearance of opportunistic knapping, and the emergence of characteristics that refer to the Middle Palaeolithic, such as standardisation of flake production, or adapting knapping methods to the dimensions of the raw materials (discoid knapping for quartzite, knapping on an anvil for small flint pebbles). The whole industry from layer 4 and its three levels (4a, 4b and 4c)-13,212 artefacts-has been studied. The lithic industry includes flakes (33.1 %), flake fragments (28.4%), debris (21%), retouched flake tools (7%), cores (4.3%), pebble tools (3.2%), pebble fragments (1.7%); 1.3% are miscellaneous pieces. The raw materials used in layer 4 are flint (71 %), quartz (13 %), sandstone (10%), microgranite (5%), quartzite (0.8%) and glossy sandstone (0.5%) and were selected on the ancient beaches in or near the deposit. Retouched flake tools are mostly denticulates (68.2%), scrapers (19.7%) and notches (12.1 %). A paving structure has been revealed in layer 4 (level 4b) as highlighted by S. Hinguant during the 2000 excavation campaign and is presented in this article. This is an important element, as we have little information about Lower Palaeolithic settlements. Evidence of the use of fire has been provided by the presence of 28 artefacts with thermal altérations, although no hearth was noted during the excavation. Layer 4 of the Menez-Dregan I site has been attributed to the 'Colombanian' by J.-L. Monnier (Monnier, 1996) due to the composition of the lithic industry: prédominance of pebble tools within a heavy tool assemblage associated with retouched tools on flake-supports (notches, denticulates), and by the 'Clactonian' aspect of the knapping (wide slightly faceted butts, strong bulbs, wide open flaking angles). The Levallois method is absent, bifaces are absent or extremely rare, there are few scrapers. The Colombanian proves to be a facies of the Lower Palaeolithic, contemporary with the Acheulean but typologically distinct. However, standardisation of flake production leads us to foresee a change in the lithic industry of layer 4, and allows us to highlight a transition period from the Lower Palaeolithic to the Middle Palaeolithic in the later occupation of this deposit. This study is a contribution to the documentation of the diversity and variability of Lower and Middle Palaeolithic lithic industries, demonstrating that the usual criteria of allocation to a facies do not apply equally to every site. We agree with G. F.