Menez-Dregan I, layer 4: A transitional layer between the Lower and Middle Palaeolithic in Brittany

摘要

Menez-Dregan I is a Lower Palaeolithic site situated at Plouhinec, Finistere, 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 the boundary between the Lower and Middle Palaeolithic. Geological correlations tend to place layer 4 in MIS 9 or 7, although the only TL dating obtained for this level gave an age of 223 +/- 23 ka. 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 illustrate the transition between the Lower and Middle Palaeolithic. We present the lithic industry of this layer, which simultaneously combines Lower Palaeolithic characteristics, such as large quantities of pebble tools (due to the environment of the site), and the emergence of characteristics that are common 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, bipolar flaking on an anvil for small flint pebbles). The lithic industry from layer 4 and its three levels (4a, 4b and 4c) has been analysed. Layer 4 of Menez-Dregan I has been attributed to the "Colombanian" on the basis of the composition of its lithic industry: a predominance of cobble tools amongst heavy-duty tools, retouched light-duty tools on flake-supports comprising mostly notches and denticulates, and a knapping method akin to the "SSDA - Clactonian". The Levallois method is absent, bifaces are absent or extremely rare, and there are few scrapers. The Colombanian proves to be a Lower Palaeolithic industry contemporary with the classic Acheulean, but typologically distinct. However, standardisation of flake production leads us to foresee a change in the lithic industry of layer 4, and highlights a transitional period from the Lower Palaeolithic to the Middle Palaeolithic in the latest 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 large amount of cobble tools in layer 4 is an unchanged component due to environmental constraints. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.