Économie préhistorique des îles bretonnes (France) : apports des industries lithiques du Néolithique récent et final

The economy of an island territory, and particularly its supply dynamic, is an area that has been little explored in terms of the installation of the first agro-pastoral societies on the English Channel/ Atlantic seaboard. Many inventories and field campaigns have been carried out over the past five years on islands off the Brittany coast (Daire, 2009 ; Daire and Hamon, 2013 ; Pailler and Gandois, 2011 ; Le Bihan et al., 2010 ; Large, 2014, etc.). The quality and the quantity of the data are variable according to the islands concerned (recent or old inventories, presence/ absence of surveys or excavations), highlighting our ignorance of the archaeology of certain islands (such as Belle-Île-en-Mer). Nevertheless, these archaeological studies have led to a preliminary synthesis of the dynamics of occupation of these island spaces, from the Neolithic period to the Bronze Age (Audouard, 2014). The most important part of an ‘ archaeology of islands’ is to consider that islanders are not necessarily isolated people. In the book The archaeology of Islands, P. Rainbird points out that so far, archaeological studies on islands have mostly been based on the idea that the island area as a geographical unit ensured the unit of analysis which emerged. The author emphasizes in his argument the fact that the islands are part of a community of ‘ people of the sea’ that cannot be limited to the island, and that must be understood in a wider geographical area that contains oceanic expanses and other nearby islands and continental coasts. The sea is not the border, but the continuity of the territory : “ We need to accept that people were at home with the sea [...]” (Rainbird, 2007). In the particular framework of our studies on the islands of Brittany, this approach has made it possible to address questions about the degree of insularity of these territories, the existence or absence of particularities, as well as the links maintained between the islanders and their continental neighbours. The main problematics of our research can be explained as follows : Firstly, did the resources of these islands, both varied (terrestrial and marine) and limited (small cultivable land area, complex hunting management), result in an adaptation of lifestyles ? Did the populations merely endure their environment or did they overcome the constraints through the dynamics of contacts and exchanges ? The lithic industry is a relevant medium to address the terms of supply of raw materials, and examine the importance of imported rocks. In this article, the results presented cover the Late/ Final Neolithic period, a phase in which the exploitation of coastal resources seems rationalized, and where trade with the continent attests to unequal situations between the islands of the Iroise Sea and the Atlantic islands : examination of the lithic industry from different sites of the Breton peninsula (from the Molène archipelago to the island of Belle-Île-en-Mer) points to overexploitation of coastal flint pebbles, explaining their decrease in size from the beginning of the Neolithic. This overexploitation of local resources was coupled with a very low call on imports, exogenous rocks being only poorly represented in the assemblages. The presence of exogenous materials (such as the Turonian flint from Grand-Pressigny) on some islands reveals the existence of contacts between the mainland and island communities, the latter appearing open to outside influences. Nevertheless, these imports are always in limited proportions, around 1% of the lithic assemblage. The abundance of flint coastal pebbles seems to have covered the needs of the insular community. Some differences between the islands are highlighted. Indeed, the islanders of southern Brittany appear to have been more integrated within the exchange networks than the islanders of the Iroise Sea. If we look at the distribution of Grand-Pressigny flint, which was a major lithic material used in exchanges during the Late Neolithic (Ihuel, 2009), the imbalance between islands is striking. The geographical distance separating the islands of the Iroise Sea from the sedimentary basins bordering the Armorican Massif may possibly provide an initial explanation for this situation. In addition to the presentation of the supply of raw material, we will also discuss the importance of bipolar percussion on an anvil within the islands’ lithic industry. With the support of several lithic studies, including systematic measurements, we will discuss the relative roles of determinism and choice in the exploitation of coastal pebbles. Finally, we will discuss the importance of the overexploitation of local resources within the insular economy at the end of the Neolithic. First, in the south Morbihan area, the multiplication of knapping spots where bipolar percussion on an anvil was exclusively used attests to an almost ‘ industrial’ exploitation of the costal pebbles. This overexploitation of the local resource on islands can also be observed with the specific case of the sites with abundant borers. Six occupations, from the island of Molène to the island of Oléron, are distinguished by an abundant presence of borers, linked to the manufacturing activity of shell ornaments on the island of Oléron (Laporte, 2009). In fact, those specialized sites (knapping spots, sites with abundant borers) could have played a key role in the islanders’ economy at the end of the Neolithic. In that case, the overexploitation of local resources could be seen as testifying to dynamic communities, in strong interaction with the mainland (despite the lack of exogenous rocks). Furthermore, the localization of those specialized sites on ‘ small islands’ and ‘ islets’ could also demonstrate an economic and cultural organization of the landscape, between the biggest islands (such as Ouessant, Belle-Île-en-Mer) and the smaller ones, dedicated to specific activities. The role of islands in the economic operation of the first agro-pastoral societies on the French Atlantic coast is a vast area of research where many developments are appearing.L’économie d’un territoire insulaire est un thème encore peu exploré sur la façade Manche-Atlantique, et ce plus spécialement dans le cadre de l’installation des sociétés agropastorales et de leurs dynamiques d’approvisionnement. Aborder une recherche de cet ordre implique une série de questionnements (Audouard, 2014) : – les ressources des îles, à la fois limitées (surface exploitable réduite, gestion cynégétique complexe) et diversifiées (ressources terrestres et maritimes) ont-elles entraîné des adaptations économiques et sociales ? ; – les populations ont-elles dépassé les contraintes de leur environnement grâce à un dynamisme de contacts et d’échanges ? L’industrie lithique se présente comme un média pertinent pour aborder les modalités d’approvisionnement en matières premières et examiner l’importance des roches importées. Cette recherche portera sur la période du Néolithique récent-final, cette dernière s’affirmant comme une phase où l’exploitation des ressources littorales semble rationnalisée et où les échanges avec le continent attestent de situations inégales entre les îles de la mer d’Iroise et les îles atlantiques. En effet, l’examen de l’industrie lithique de différents sites de la péninsule bretonne (de l’archipel de Molène à Belle-Île-en-Mer) indique une surexploitation des galets de silex côtiers, dont la diminution de la taille depuis le début du Néolithique en serait la conséquence. Cette surexploitation des ressources locales se double d’un faible appel à l’importation, les roches exogènes n’étant que peu représentées dans les assemblages. Sur ce point, nous verrons que toutes les îles ne sont pas forcément isolées des échanges avec le continent, et que la proximité avec les marges sédimentaires du Massif armoricain joue un rôle déterminant. Nous évoquerons la multiplication sur les îles et îlots des sites spécialisés tels que les amas de débitage et les sites à perçoirs abondants. Les caractéristiques observées feront l’objet de comparaisons avec les données disponibles sur les proches sites continentaux, et d’interroger l’impact de l’insularité sur leur émergence.Audouard Lorena. Économie préhistorique des îles bretonnes (France) : apports des industries lithiques du Néolithique récent et final. In: Bulletin de la Société préhistorique française, tome 113, n°3, 2016. pp. 571-586