Sedimentological and geochemical traces of metallurgical activity in the Świślina River valley (central Poland) at the Doły Biskupie site

Abstract

Prehistoric and historic iron metallurgy in the Holy Cross Mountains in central Poland developed along with human Przeworsk Culture activity (during the Roman period) and within the boundaries of the Old-Polish Industrial District (OPID) during the Middle Ages and during recent centuries. At the Świślina catchment, there are many archaeological sites showing intense prehistoric metallurgical activity. The later medieval and modern iron industry was significantly smaller. At the Doły Biskupie site, slags and microscopic iron spherules (hammerscales) were found in alluvia. The microscopic spherules separation method (MSS) enabled analysis of these small artefacts created during iron ore smelting and forging. Iron spherules were detected in floodplain sediments, which are characterized by increased content of trace elements. The presence of these artefacts in shallow sediment layers in the confluence section of the river may be an indicator of archaeologically confirmed prehistoric metallurgical activity in the catchment area. Study of these residues enabled an attempt to reconstruct the river valley environment during the prehistoric and historical period. The MSS method can be used to detect iron spherules in alluvia in other river catchments, confirming the presence of yet-undiscovered bloomery sites.