Archaeometallurgical Investigations of the Early Iron Age Casting Workshop at Kamieniec. A Preliminary Study

Abstract

This preliminary study characterizes the bronze metalworking on a defensive settlement of the Lusatian culture in former Kamieniec (Chełmno land, Poland) as it is reflected through casting workshop recovered during recent excavations. Among ready products, the ones giving evidence of local metallurgy (e.g. casting moulds and main runners) were also identified. With the shrinkage cavities and dendritic microstructures revealed, the artifacts prove the implementing a casting method by the Lusatian culture metalworkers. The elemental composition indicates application of two main types of bronzes: Cu-Sn and Cu-Pb. Aside these main alloying additions, some natural impurities such as silver, arsenic, antimony and nickel were found which may be attributed to the origin of the ore and casting technology. The collection from Kamieniec was described in terms of its structure and composition. The investigations were made by means of the energy dispersive X-ray fluorescence spectroscopy (ED-XRF), scanning electron microscopy (SEM) coupled with an energy dispersive Xray analysis system (EDS) and optical microscopy (OM). In order to fingerprint either local or non-local profile of the alloys, the ED-XRF data-set was statistically evaluated using a factor analysis (FA).

Bronze Jewellery from the Early Iron Age urn-field in Mała Kępa. An approach to casting technology

“…Nevertheless it was probably an additive used by the Lusatian metalworkers not for economic but rather technological reasons. This, indeed, is the case of the Chełmno group metalworkers where lead-contaminated alloys become common, alongside mainstreamed tin-bronzes [6,8].…”

“…Consequently, the presence of the nail earrings in Mała Kępa may have led towards the model of exchange contacts between societies of the CuyaviaChełmno land region through the South-Eastern cultural passageway. It would also seem meaningful that importing or local imitating of the steppe-styled objects by the Lusatian metalworkers was still a relatively new phenomenon tied into the increasing presence of the Nomads in Central Europe or rather their strong cultural impact on the northern province of the Lusatian culture during Ha D [6,[17][18][19].…”

“…This gave rise to conception that the Chełmno group metalworkers could have been fully aware of the advantages (fluidity and castability) and disadvantages (ductility) of alloying the tin-lead bronze. It is symptomatic that the band ornaments recovered from the casting workshop in Kamieniec render such conception even more likely [6,8]. It is meaningful that both rings were deposited into grave no 38 within the oldest zone of the urn-field in Mała Kępa (with open-ring-like grave agglomeration) and thus it is almost evident that the Chełmno group metalworkers were familiar with such metallurgical know-how during the Late Bronze Age already.…”

“…necklaces), while the lost-wax method was used rather to cast small objects (e.g. nail earrings) and those more advanced in shape, like decorative pendants [3][4][5][6][7][8].…”

Reconstruction of the Casting Technology in the Bronze Age on the Basis of Investigations and Visualisation of Casting Moulds

“…Beeswax patterns were covered with clay, dried and burned in the fire, giving a mould the high-temperature resistance and durability in contact with liquid metal. This method ensured considerable smoothness and the accuracy of pattern reconstruction [5,[14][15]. Moulds were poured with tin bronze or tin-lead bronze, as well as lead bronze.…”