El marfil en la edad del cobre de la península ibérica. Una aproximación tecnológica, experimental y contextual a las colecciones ebúrneas del mega-sitio de Valencina de la Concepción - Castilleja de Guzmán (Sevilla)

Laburpena

The main objective of this doctoral thesis is to determine the economic and social role of ivory in the southwest of the Iberian peninsula within Copper Age societies, through the particular case of the Valencina de la Concepción-Castilleja de Guzmán (Seville) mega-site, and its comparison with other contexts. Although the approach to this assemblage of ivories has been oriented from a technological point of view, very specifically directed, although not only, to the recognition of techniques and tools, procedures and ways of doing, this thesis has a multidisciplinary approach, combining conservation, restoration, technology, experimentation and contextual analysis. Ivory is part of the broader framework of exploitation of biotic resources, specifically animals. During the Late Prehistory, hard animal tissues were used to produce tools oriented to activities of production/acquisition, but also to manufacture artefacts with marked symbolic character. The selection of a certain raw material reflects precise cultural choices. Therefore, osseous resources, because of their varied and versatile use, constitute a key piece for the knowledge of the societies of the past. Context in which ivory can help to reveal aspects of economic, social, cultural and ideological nature. At a theoretical level, the technological approach has been based on the concept chaîne opératoire, as a tool that has the ability to guide the study through each step of the analysis and interpretation (Soressi and Geneste, 2011: 341). This approach has materialized in a practical way in a specific methodology and vocabulary. Thus, the empirical study and analysis of the material are based on: 1) the recognition of the raw material (proboscidean ivory) through the deep knowledge of its specific characteristics, 2) the restoration of the artifacts in bad preservation conditions for its correct identification, 3) the classification of each artefact in a category of analysis (blocks, blanks, pre-forms, production wastes, finished objects and un-determined artifacts), 4) the recognition of techniques, procedures and modes, and 5) the practical implementation of some experiments as a method of testing the hypothesis about the manufacture of some pieces, and the general exploitation of the elephant tusk. The contextual analysis is based on the type of structure in which the material appears, the quantity (estimation of the number of objects and weight), the origin of the raw material and its representativeness within the ensemble of bone industry of the structure, the NMI in the structure and the chronology. We have studied 383 artifacts of different assemblages of materials from Valencina that according to the bibliography contained ivory items. The material comes from 12 calcolithic structures belonging to eight sectors of the site. Of the structures studied, four relate to activities other than burial, possibly linked to artisanal and productive activities (UC402 of Sector IES, UC5 and UC63 of Sector DÍA and ¿Structure 50? of PPMatarrubilla), and eight are structures with ritual/funerary character (Montelirio tholos, Structure 10.042-10.049 and Structure 10.076 of the Sector PP4-Montelirio, Matarrubilla tholos, Depósito de Agua tholos (Castilleja de Guzmán), and Tomb 2, Tomb 3 and Tomb 5 of the Divina Pastora- Urbanización Señorío de Guzmán sector, in addition to a piece without UE / Structure (and therefore decontextualized) of PP4-Montelirio sector. Although the sample of study may in principle seem reduced, the amount of material present in Valencina has provided the perfect laboratory for the first complete technological study of Iberian prehistoric ivory, obtaining results that shed light on technological, experimental and contextual issues, on the management and economic and social value of this raw material. Thus, Valencina stands out with almost 8.8 kg of ivory, a figure that far exceeds for the moment the weight of any other Iberian chalcolithic site. The varied origin of this raw material has already been reported (Schuhmacher, 2012a and 2012b; Schuhmacher et al., 2013a, García Sanjuán et al. 2013), with two extra-peninsular sources (Loxodonta africana africana and Elephas maximus) and a third one, Elephas (Palaeloxodon) antiquus, that could be collected locally. On a technological level, the study reveals that the exploitation of the tusk was carried out in a systematic way, based on two different forms of exploitation (transversal and longitudinal), being the longitudinal way (through an action perpendicular to the longitudinal axis of the block) the preferential form of exploitation, with 72% of the studied ensemble manufactured from plaques obtained in this way (combs, perforated discs, lids, handles, plates, etc.). Among the identified techniques, the use of sawing by abrasion with rope (Sciage au fil sablé) for the transversal segmentation of the tusk has been observed for the first time in Iberia. This find calls into question the tendency to assume that sawing with a metal saw is the preferred technique, or the only one. It has been equally very interesting to prove experimentally that the lithic drillers identified so far in the specific literature of Valencina could not be responsible for the perforations observed in the ivories, and that very possibly these had to be done by mechanical-manual systems, such as arc-drills, with very thin borers. The recognition of a repair case, the possibility of having detected a case of fragmentation and redistribution of pieces of ivory, the context (funerary, mainly tholos type structures) and the typology of the objects, reflect the special character of this material. Not a single ivory object has been studied that can be ascribed to productive or maintenance activities (as tools), so the whole set reveals its use as sociotechnical and deotechnical artifacts. The variability of types of ivory objects is very wide in Valencina (beads, cylindrical containers, boxes, perforated discs, handles, plaques, combs, lids, containers, pendants, etc.), and the assemblage has a distinctive feature: each tomb has unique objects, which are not repeated in other tombs. This suggests that the production of ivory objects was not "serial", but perhaps "persnalised", directed towards specific consumers (individuals of special importance or with the ambition to stand out within a certain society or group?). It seems therefore that ivory played a predominant role in the construction of the funerary ritual and social order of the calcolithic Valencina, and although a large part of the material comes from collective burials, some individuals had privileged access to large quantities of exotic raw materials, like amber, cinnabar, gold, ostrich egg, rock crystal, etc., among which the ostentation of large quantities of ivory, and unique objects made with it, were used as status markers.