Organisation de la chaîne opératoire en métallurgie du fer aux iie-iersiècle av. J.-C.,sur l’oppidum d’Entremont (Aix-en-Provence, Bouches-du-Rhône): la circulation du métal

La circulation du fer, conditionné sous forme de loupes ou de demi-produits est particulièrement mal connue, pour les périodes anciennes en Europe tempérée. Le cas d’Entremont (Aix-en-Provence, Bouches-du-Rhône), oppidum de la fin du second âge du Fer, parfois considéré comme l’agglomération principale des Salyens, permet d’aborder ces problématiques. En effet la mise en évidence, et l’étude archéométrique, d’une chaîne opératoire complète de post-réduction (épuration de loupes, fabrication de demi-produits, manufacture d’objets), permet d’étudier l’organisation de ces activités à plusieurs échelles. Celle du site, par l’identification d’une sectorisation des activités de post-réduction, conduisant à supposer la circulation de demi-produits de forme normalisée au sein de l’oppidum. À un niveau régional également, par la mise en évidence de l’intégration du site à un réseau de diffusion de loupes brutes, à partir d’ateliers de réduction environnants. La spécialisation des artisans et le caractère intensif de l’activité sidérurgique, au sein de ce centre politique et économique majeur sur le territoire des Salyens, amène également à s’interroger sur les débouchés de ses productions et notamment de ses demi-produits.Little is known about the circulation of iron, in the form of half-products or bloom, for the protohistorical period in temperate Europe. The example of Entremont (Aix-en-Provence, Bouches-du-Rhône), an oppidum dated to the end of the Iron Age, and sometimes considered as the principal town of the Salyens, allow us to address these problematics. The archaeological and archaeometrical study, of objects and waste-products produced at each step of the post-reduction process (bloomsmithing, fabrication of iron semi-products and objects) permit us to study the organisation of these activities at different scales. At the level of the site, by the identification of zoning of the post-reduction activities, leading us to suppose the circulation of standardised iron semi-products inside the oppidum. Equally, at a regional scale, from evidence suggesting the integration of the site into a diffusion network of raw bloom material, from surrounding reduction centres. The specialisation of blacksmithing and the intensity of the metallurgical activity inside this major political and economic centre for the Salyen’s territory, also lead us to reflect upon the subsequent diffusion of its products, and especially its half-products

The multidisciplinary approach (archaeology and archaeometry) to bloomsmithing activities in France: examples of results from the last twenty years

Over the last twenty years, archaeological and archaeometrical research implemented in France has made it possible to define the various stages of the chaîne opératoire in iron and steelmaking as well as the indicators that are linked to them (archaeological structures, wastes). These studies reveal that the chaîne opératoire may (or may not) split in space and time, but may also contain varying degrees of intensity (mini-maxi production). This implies that the production sites can be from different natures: they may include partial or complete chaîne opératoire, and are part of a social context (e.g., rural, urban, specialized, or domestic craft). The relationships within the chaîne opératoire create links between the sites and form a technological, economic, and social network through trade in semi-finished and manufactured products. The evolution of these networks must be studied by taking into account the cultural and political contexts of each period to draw up a coherent understanding of this organization. The determination of site activities (smelting, refining, elaboration, consumption, recycling), as well as intensity, allow a dynamic cartography of these activities, both synchronic and diachronic, to be realized. The physicochemical linkages between the ore, the smelting slag, the post-smelting slag, and the metal produced make possible an eventual understanding of the connection between sites that are part of the same exchange network. This in turn reflects the regional development of metallurgical organization and the trade in iron semi-products and manufactured goods. The typological attribution (morphology, level of impurities, iron/carbon composition, phosphorus contents, etc) of semi-products worked on the forging sites also makes it possible to refine the vision of what circulate and of what the sites acquire. Thus, an archaeological and historical study of these data can structure the relative image we have of these relations in the various periods

An archaeological and archaeometrical approach of ferrous semi-product : a diachronic qualitative typology (VIIth c. BC. - IInd c. A.D.)

From the raw bloom to the final product, depending on the nature of the latter, several semiproducts can be obtained along the chaîne opératoire. Some of them are directly transformed on the ironmaking site. Some other, on the contrary are marketed between several workshops, production centres or markets. On relation with the quantity of work to obtain them, or with the quality of the constituting material, they could have different values. For these reasons, understanding the way these semi-products were obtained and in which technico-economical context, but also the way they were comprehended by the ancient craftsmen and blacksmith is a fundamental aspect of ironmaking technical and economical history, whatever the period under interest is. The aim of the general overview presented here is to review, from the archaeological site to the laboratory, the different clues that allow to enlighten several aspects linked to the semi-product production and exchanges. Indeed, even if the archaeometric observations are scientific facts, they can never be considerate out of any archaeological and historical context. Thus, a constant come and go must be undertaken between the physico-chemical data and this context. For example, as far as the metal quality is concerned, added to the fact that numerous parameters will influence the mechanical behaviour of the material, it is important to know that it is not the only aspect that will determine the use of a given material. It is merely a more complex conjunction of its quality, the skill of the blacksmith, the availability of the metals in the technico-economical context under study, etc. Depending on the place in the chaîne opératoire, semi products can be more or less elaborated and of different natures: bloom slightly hammered after a first compaction treatment, ingot obtained after a more important hammering and cleansing, currency and socket bars, with a thinner shape closer to the form of the final artefact, etc. Semi-products can question several aspects of archaeological and historical studies. At the archaeological site level, it is of great interest to understand the spatial and technical organisation of the site, and sometimes of different production sites in the same area and period. It is also important to evaluate the nature of the forging sequences, the type of activities and production and the quantities. Another crucial question is the nature of the metal that is produced and marketed, linked to his mechanical behaviour, and the value it has in the different technicoeconomical contexts. To study this point it is necessary to try to evaluate it by identifying the parameters that mainly influence this quality and trying to define reproducible study methodologies in order to compare the different artefacts. Then, another important point is to study the semi-product diffusion and exchange on more or less long distances. To this purpose, crucial chemical data can be found in the slag inclusions (SI) embedded in the metallic artefact, that offers the possibility to identify homogeneous or heterogeneous corpuses but also, in specific cases, to enlighten the production region of the artefacts. Our research for 10 years concerns an important number of sites and artefacts covering periods from the 1st iron age to medieval times. Following the methodology of former works made in east of France and in the Swiss Jura, in the frame of several PhD works, we significantly completed our pluridisciplinary and diachronic investigations on the French territory for the following areas: Grande Limagne d'Auvergne, Nord du Bassin parisien, Narbonnaise (Languedoc-Roussillon, Provence-Alpes-Côte-d'Azur), Normandy, Pays de Bray, Pyrénées ariégeoises and an important part of central Burgundy. More than 600 ironmaking, sites, tens of historical buildings and several hundred artefacts were studied. These works allowed us to precisely define the internal characteristics of the materials in order to evaluate on the one hand the real nature of the forging activities on given sites, on the other hand the qualitative criteria that could help to identify some specificities and follow exchanges and technical breaks

Les fortifications du Frankenbourg à Neubois (67): Rapport intermédiaire

La campagne de fouille de 2019 au Frankenbourg a tout d’abord offert la possibilité de compléter les études engagées sur la fortification gauloise : la structure du rempart a été à nouveau étudiée et la couche sur laquelle est édifiée la fortification a été dégagée et prélevée en vue d’analyses micromorphologiques. Les sondages ouverts au niveau du rempart inférieur ont également permis la mise au jour des premières structures liées à l’occupation du Bas-Empire ; ces deux aménagements restent toutefois à interpréter. Deux terrasses, situées peu en amont du rempart ont également été sondées : les résultats sont relativement maigres et montrent essentiellement l’importance de l’érosion dans ces secteurs.Un petit sondage a aussi été ouvert à l’angle nord-ouest du « mur païen » afin d’en étudier la structure. Celle-ci est relativement mal conservée, une seule assise subsiste, et semble plutôt correspondre à une réfection de la fortification originelle. Une seconde phase de construction inédite, un mur maçonné dont les moellons sont liés au mortier de chaux, a été mise au jour, elle pourrait dater du XIIe siècle.Enfin, la totalité du mobilier métallique découvert depuis 2014 ainsi que les matériaux liés à la métallurgie du fer découverts sur le site ont été étudiés ; tout comme l’important lot de monnaies romaines exhumé entre 2018 et 2019

Carsix (Eure). Carrefour de Malbrouck

Un diagnostic a porté sur une surface de 72 713 m², en terrain agricole, sur un projet de zone d’aménagement communautaire. Deux occupations du bas Moyen âge semblent s’être succédé. La période la plus ancienne couvre les xiiie-xve s. et se concentre à l’extrémité NO du secteur avec une enceinte fossoyée délimitée par un fossé bordé d’un talus. Quelques trous de poteau et un four implanté dans le fossé sont les vestiges d’une occupation domestique. Dans cette enceinte, cernée de zones enclose..

Les demi-produits de fer au I^er millénaire a.C. en Europe continentale : potentialités d’études

International audienceStudies of semi-worked products of iron, varieties of ingots, focus on two themes: coinage and metallographic analyses. This article is a presentation of other means of researching this topic, associated with metallurgy, which can be approached from this raw material.Les études sur les demi-produits de fer, sortes de lingots, se sont concentrées autour de deux thèmes : la monnaie et les analyses métallographiques. Cet article se veut une présentation d’autres pistes de recherches, liées à la métallurgie, abordables à partir de l’étude de cette matière première

Le fer, entre matière première et moyen d’échange, en France, du VII^e au I^er s. av. J.-C. : approches interdisciplinaires

National audienc

Technotypologie des "currency bars" issus de la Saône : prolongements interdisciplinaires

International audienc

Les demi-produits de fer au I^er millénaire a.C. en Europe continentale : potentialités d’études

International audienceStudies of semi-worked products of iron, varieties of ingots, focus on two themes: coinage and metallographic analyses. This article is a presentation of other means of researching this topic, associated with metallurgy, which can be approached from this raw material.Les études sur les demi-produits de fer, sortes de lingots, se sont concentrées autour de deux thèmes : la monnaie et les analyses métallographiques. Cet article se veut une présentation d’autres pistes de recherches, liées à la métallurgie, abordables à partir de l’étude de cette matière première