The spread of technical innovations such as iron smelting required the availability of natural resources, first of all iron ores, and manual skills along with social acceptability and necessity. The project investigated the beginnings of iron smelting in the area of the Przeworsk culture (Poland) based on the hypothesis that the earliest stages of local and regional iron production coincide with the emergence of the Przeworsk culture within the 2nd century BC.
Research
The project tried to understand iron smelting in its cultural spread, by integrating technical and socio-economic aspects framing the spread of this innovation. Thereby the spread of iron smelting is understood as a recursive learning process, involving a relative potential for change resulting from technical solutions and adaptations.
Two spatial scales were integrated within the project: A comparative statistical analysis of grave goods for different regions in Poland allowed deriving conclusions on the spatial distribution of early iron objects on a meso to macro scale. The catchment of the Widawa River served as a case study region. In the surrounding of the present day town of Namyslow a cluster of Przeworsk sites, whose archeological finds point to early iron smelting was investigated by conducting own field research. Therefore manuscripts and excavation files of previous excavations were reviewed and moreover geomagnetic measurements, a survey and a small scale excavation were conducted. Furthermore, the landscape evolution was reconstructed dating first human impact to the Bronze Age. Iron slags and bog iron ore samples were geochemical and mineralogical analysed in order to derive information on the suitability of local bog iron ores as raw material and the efficiency of the smelting processes in local bloomery furnaces.
Results
The crystalline mineralogical composition of local bog iron ores is dominated by quartz and goethite. Fayalite, wüstite and quartz represent the main minerals of the analysed slags. The ores show an iron content of max. 45.4 mass% Fe (64.9 mass% Fe2O3), while iron contents in the slags vary between 37.9 and 56.0 mass% Fe (48.7 and 72.0 mass% FeO). Iron slags from the study area show a typical fayalite-dominated mineralogical composition, which points to process temperatures above 1200 °C. Concentrations of manganese and phosphorus point to the exploitation of bog iron ores as raw material for iron smelting and not to the utilisation of ores from iron gangue minerals.
The mineralogical composition of the ores is, as typical for bog iron ores, dominated by goethite. The iron–silicon ratio is highly variable and represents different bog iron ore formation stages.
The results from the Widawa catchment point to an onset of iron production in the Roman Iron Age: and consequently 400 years later than expected. However it cannot be excluded, that small-scale iron smelting started with a low intensity already during the Pre-Roman Iron Age; but yet archaeological evidence do not allow resolving this phase.
Overall, there is hardly any evidence of iron smelting for the pre-Roman Iron Age in Poland. Therefore, the question of iron objects in pre-Roman Przeworsk culture seems to be one of the social relations, the communication and exchange networks both on intracultural and in particular on the intercultural level (above all to the La Tène culture) and is not the result of a pronounced local or regional iron production.
Finally, the question of the technology transfer to the area of the Przeworsk culture is examined and an alternative explanation to the communis opinio, which derives the introduction of iron smelting technique from the La Tène culture is formulated: Results point to a linkage of technology transfer with Elbgermanic groups during the transition to the Roman imperial period. This development seems to be a supraregional phenomenon of the transformation phase from the La Tène period to the Roman imperial period in Central Europe.
Parts of the project have been presented at major international conferences and workshops and in several articles, e.g.: