Archaeometric characterization of Roman dolia from the northeast of Hispania Citerior-Tarraconensis
The ‘dolia’ and wine production
From the end of the 2nd and beginning of the 1st century BC, the province of Hispania Citerior (called Tarraconensis after the territorial organisation of the Emperor Augustus) was characterised by the development of a production system based mainly on wine-growing and wine trade. Archaeological research shows the presence of numerous wine and pottery settlements that manufactured the ceramic containers used for the transport and marketing of wine (the amphoras), in the coastal and pre-coastal sector of Catalonia. The settlements are concentrated preferably on the alluvial plains, around urban centres – some pre-existing such as Emporion and Tarraco, and others newly founded, such as Iluro (Mataró), Baetulo (Badalona), Barcino (Barcelona) or Blandae (Blanes) – mainly in ports or near rivers and streams that ensured the commercial diffusion of amphorae.
However, the winemaking phenomenon did not develop in a parallel or unitary manner throughout the territory. The first agricultural operations specializing in vine cultivation and wine production date back to the end of the 2nd century BC and these activities are represented by the areas used to store wine in dolia, large, static ceramic containers in which the must was processed and stored. These areas are more extensive in the wine-producing settlements dating from the mid-1st century BC, when the wine pressing structures and other large infrastructures were introduced, and especially in the high-imperial period, corresponding to the time of the greatest productive and commercial boom in wine. Wine was initially destined for South Gaul through the maritime trade in locally produced amphorae.
The amphoras used in the maritime trade of Hispania Citerior-Tarraconensis wine have been widely studied from various methodological perspectives: i.e., Archaeology, Archaeometry, Epigraphy, etc. On the other hand, other ceramic materials related to the wine production process, such as dolia, have not been so interesting for the scientific community. The research has been limited to documenting them in the stratigraphic sequence, quantifying the fragments and providing some data on epigraphy in the cases that contain marks or graffiti. Only recently, Ch. Carrato has carried out a systematic study for the Galia Narbonensis, while Tremoleda and others have studied the dolia made in the pottery of Ermedàs (Cornellà de Terri, Baix Empordà). In both studies the morphological characteristics of the containers have been systematized in order to create a typology, and the archaeometric characterization of the ceramic pastes has been carried out by V. Martínez Ferreras.
The ‘dolia’. Archaeological Contextualization and Archaeometric Characterization
The present project aims to address the study of the production processes and commercial dissemination of these large containers in the northeast of the province of Hispania Citerior-Tarraconensis in the high-imperial period from a multidisciplinary perspective. The aim is to carry out the archaeological contextualization and the archaeometric characterization of about 50 dolia found in various sites of different entity and functional category, in order to evaluate the productive and commercial system of these large containers. The archaeological settlements under study correspond to:
1) Potteries or dolia manufacturing centres, such as Ermedàs (Cornellà de Terri), el Collet de Sant Antoni (Calonge, Baix Empordà), La Fornaca (Vilassar de Dal, El Maresme), Can Ferrerons (Premià de Mar, El Maresme) and Cal Ros de les Cabres (El Masnou, El Maresme).
2) Winemaking centres in Villae or in rural areas, with the presence of wine processing and storage areas in Dolia, such as Pla de l’Horta (Sarrià de Ter, Girona), Can Ring (Besalú, La Garrotxa) and El Moré (St. Pol de Mar, El Maresme).
3) Urban centres and port cities, where dolia appear both in living spaces and in market and port areas, as would be the case in Emporiae (Escala, Alt Empordà), Iluro (Mataró) and Baetulo (Badalona).
The study includes the chrono-typological contextualization of the dolia selected among the mentioned deposits, and the archeometric characterization of the ceramic slurries using chemical, mineralogical and petrographic analysis techniques. The macroscopic examination of fresh fractures by means of the Olympus SZ61TR micro-stereoscope will allow a first classification of the samples according to the macroscopic characteristics of the pastes. The petrographic study by optical microscopy with polarizing light provides very relevant information about the origin of the containers and, especially, about the technological processes of production: the selection and processing of the raw materials, such as the type of clay and degreaser, the modeling, and the firing. Mineralogical analysis by means of X-Ray Diffraction (XRD) allows us to approach the geological environment of raw material supply, which will respond to the area of origin where the production centre is located. It also provides information on the firing process (temperature and atmosphere inside the furnaces). Finally, chemical analysis by means of X-Ray Fluorescence (XRF) will make it possible to determine the compositional characteristics or reference groups of the productions of the potteries studied, and to associate dolia of habitats and urban centres to some potteries or specific areas.
This is a preliminary, although complete, study on the dolia alto-imperiales of Hispania Citerior-Tarraconensis, which aims to investigate and evaluate, for the first time in archaeological research, the manufacture and marketing of these containers from a multidisciplinary perspective, in order to recognize the producing areas, assess the degree of formal and technological standardization among various sites and productive areas, and the degree of commercial dissemination in the interior of the province and with neighboring Galia Narbonensis.
Dra. Verónica Martínez Ferreras
Investigadora Ramón y Cajal (Ministerio de Ciencia e Innovación). Equip de Recerca Arqueològica i Arqueomètrica de la Universitat de Barcelona. Departament d’Història i Arqueologia, Facultat de Geografia i Història.