Archaeometallurgical studies on the slags of the Middle Bronze Age copper smelting site S1, Styria, Austria

Abstract

The copper smelting site S1 in the Eisenerzer Ramsau Valley, Styria, is the largest Bronze Age copper smelting site excavated in the Eastern Alps. The site was almost completely excavated from 1992 to 2006 and ten roasting hearths, six double furnaces, a number of pits of variable size, form and function, and three separate slag dumps have been recorded. The use of this smelting site covers the whole period of the Middle Bronze Age from the 16th to the 13th century BC and might extend as far as the 11th century BC. The aim of this archaeometallurgical study is the reconstruction of the smelting process at this site and the discovery of possible diachronic changes or developments in the technology of smelting during the different phases of use. Therefore slags of the different archaeological phases were analysed for their chemical and mineralogical composition. A few slags were analysed with Mössbauer spectroscopy to obtain further information about the conditions during the smelting process. The results of the analyses show that nearly all slags belong to one particular step of the smelting process which was the production of raw copper or copper matte under reducing conditions at temperatures around 1250 °C.