Adaptation to raw materials intra-variability: Examples from three Middle Palaeolithic surface stations of the Hérault Valley, France (Les Geissières, Saint-Saturnin and Camillo)

Up to now, little was known about the Middle Palaeolithic from the Hérault Valley (France). Recently, systematic surveys have led to the discovery of several surface stations on river terraces. Some of these have yielded stone tools made from unusual raw materials, such as, brecciated quartzites and jasper-like rocks, as well as quartz and rare flints. These rocks are found in primary position in the Montagne Noire area, and are also available in the alluvial deposits of the Hérault and its tributaries in the form of more or less rounded cobbles. These raw materials are very heterogeneous even within a single cobble. Their inter and intra-variability has been found to have induced specific knapping strategies as hominins adapted to - or took full advantage of - their special petrographic characteristics. Here we present data from three Middle Palaeolithic open-air stations (Les Geissières, Saint-Saturnin and Camillo) to illustrate adaptive knapping strategies performed by Neanderthals. In addition to the technological analysis, experiments were also conducted to test some of the identified methods, such as bipolar-on-anvil, with the aims of: 1) evaluating flake production efficiency and 2) recognizing specific traces left on the products by this method. This enabled us to better identify archaeological artefacts in this particular alluvial context. The study shows the use of stone reduction methods that allowed the knappers to adapt to the constraints posed by the raw materials: Discoid sensu lato (bifacial, unifacial, partial), Clactonian and bipolar-on-anvil. Methods more diagnostic of the Middle Palaeolithic, such as the Levallois and typo-Levallois or various Kombewa methods were used on finer grained raw materials. There are a few retouched flake tools and some pebble tools (mainly choppers). These assemblages show us that, despite the influence of the raw materials (which is more of a constraint than a limit), Neanderthals achieved their goals through a variety of methods. These surface stations make it possible to better perceive adaptive strategies in the Middle Palaeolithic in Languedoc-Roussillon, in a context where the Levallois techno-complexes prevail.