À la charnière des espaces médio-et ibéro-atlantiques et continentaux : l’ensemble métallique du Bronze final atlantique 3 ancien d’Hourtin (Gironde, France)

International audienceThe Médoc region is located in the south-west of France on the Atlantic coast. Many archaeological remains have been discovered under the sand dunes over the course of the last few decades due to the erosion of the Aquitaine shoreline. These include hoards, isolated metal objects, pottery, preserved wooden posts and flints. In 1993, a detectorist discovered 154 copper alloy objects on the beach north of the town of Hourtin. The objects were given to the Aquitaine Museum of Bordeaux, where they are still preserved today. The artefacts were scattered over a perimeter of approximately 70 meters and some were found to be clearly earlier or more recent than the Bronze Age. However, 132 objects (weighing 4,628 kilograms) do date from the end of the Bronze Age and more specifically from the Early Atlantic Late Bronze Age 3 (first half of the 10th century BC). We cannot guarantee that this discovery is a hoard, but the homogeneity and the composition of the set testify that these objects were probably deposited in the same place. Initially, the hoard was deposited inland, and not on the coast which was further out to sea at the time of the Bronze age as indicated by the clay banks that lie beneath the dune. The landscape of the Médoc has evolved a lot since Late Bronze Age, as during this period, the coastal area was wetter, overtaken by marshes with streams connecting to the ocean or the Gironde estuary.More than fifty hoards dating to Middle Bronze Age have been found in the Médoc mainly during the 19th and the beginning of the 20th centuries. They contain mainly flanged axes and palstaves. The Hourtin discovery is the first located on the coast where metal hoarding does not seem to have been common practice during the Late Bronze Age where hoards and single finds are very uncommon. Late Bronze Age 2 and Late Bronze Age 3 (1150 ??? 800 BC) hoards in Gironde have been discovered, along the Garonne and Dordogne rivers on the other side of the Gironde estuary, but not on the coast. Furthermore, the composition of the Hourtin hoard is original with Ibero-Atlantic objects such as axes and swords, which are often fragmented. The fragmentation is typical of the medio-Atlantic area at this time. Most of the bracelets are however complete in the Hourtin hoard, which is not always common in the medio-Atlantic area. The hoard contains objects from continental productions, such as Corent type bracelets and a Klentnice type sword pom­mel, uncommon in France, which has two volutes inserted in a wooden handle. Only one confirmed and three possible Klentnice pommels have been found in France, notably in Brasles (Picardy). They are also rare in the rest of Europe and are generally found in Denmark and Eastern Europe. According to H. Müller Karpe, this type of sword dates from Hallstatt B2.The presence of these objects indicates dynamic long-distance trade during the Late Bronze Age. The Médoc is located between two Ibero- and medio Atlantic cultural networks and the Hourtin discovery highlights cultural interaction around the Gironde estuary. The Pyrenees and the Atlantic coast are not obstacles for cultural contacts and trade between the north and the south of the Atlantic area and the circulation of metallic objects was important between these two entities.The elemental composition analyses of the metal objects are very insightful. When making the objects the artisan choses the main elements of alloy, which are copper, tin and lead . The lead content of Late Bronze Age copper alloy makes interpretation of the analyses complex as it is not possible to determine if the lead was naturally present in the copper ore or if it was specifically added. Trace elements such as zinc, bismuth, antimony and arsenic can discriminate Continental, Atlantic and Iberic-Atlantic productions, however the objects of Hourtin hoard show varying results and it has not been possible to determine the origin of the metals used. The analyses do underline the important trade in metal resources during Late Bronze Age all over Europe. We cannot clearly understand the role of the south-west of France in the trade dynamics of the south of the Atlantic area no other metal hoards have been found in this area. We hope that new discoveries will give us a better understanding of the trade role of the Médoc and of the south-west of France between the various Late Bronze Age cultural and economic networks.L'érosion du littoral aquitain depuis plusieurs décennies révèle régulièrement des vestiges archéologiques enfouis sous les dunes côtières. En 1993, 132 objets en alliage cuivreux, pour une masse de 4,628 kg, ont été découverts sur la plage au nord d'Hourtin (Gironde). Ces objets sont aujourd'hui conservés au Musée d'Aquitaine de Bordeaux. Même s'il est impossible de l'affirmer avec certitude, l'homogénéité typologique des objets et leur concentration sur une petite surface sur la plage laissent suggérer qu'il s'agissait bien à l'origine d'un seul et même dépôt du Bronze final disloqué par l'océan.Cet ensemble est remarquable par plusieurs aspects. Il s'agit d'un des rares connus du Bronze final atlantique 3 ancien (seconde moitié ou courant du Xe s. av. J.-C.) sur la façade atlantique française. Il concentre des objets aux affinités culturelles très variées : armements de type médio-atlantique, parures et pommeau à volutes de type continental, ainsi qu'une hache et possiblement des épées et des parures de type ibéro-atlantique. Cette diversité typologique, la faible fragmentation des parures, ainsi que sa localisation géographique, font du dépôt d'Hourtin un unicum pour le Sud-Ouest de la France. Les analyses chimiques élémentaires et isotopiques, ainsi que l'étude typologique des objets, permettent d'illustrer cette importance des échanges culturels et économiques durant le Xe s. avant J.-C., période encore méconnue en comparaison de celle du Bronze final atlantique 3 récent (IXe s. av. J.-C.), largement mieux documentée dans le nord-ouest de la France