Historical metallurgical activities and environment pollution at the substratum level of the Main Market Square in Krakow

The main purpose of the interdisciplinary research described in the present paper is to determine the characteristics of ground environment changes in the Main Market Square area, and to compare these with analyses of metal artefacts. The elemental composition of metal artefacts and the degree of contamination of archaeological layers make it possible to consider both as specific indicators, including being geoindicators that are helpful in establishing the chronology of layers. Metal-artefact samples come from archaeological layers originating from different parts of the Great Weigh House. Layers were sampled, both in this region and also in a neighbouring area at the entrance to Bracka Street — trench A. They were collected from an area of archaeological excavations, which were carried out in the years 2005–2010, reaching down to a depth of 4 meters. All artefacts come primarily from cultural layers and structures - probably linked to workshops in the early medieval settlement which functioned in the area of the Main Market Square in the 12^th and early 13^th century. However, archaeological analysis of historical material allowed us to more precisely date metal arte-facts to the turn of the fourteenth and fifteenth centuries, which was confirmed by analysis of the radiocarbon age of a sample from Room R of the Great Scales, from layer 109. Average concentrations (mg/kg) of Pb of 128454 and Cu of 108610 were determined in this sample to the AAS, which significantly exceeded of the most concentration values characteristic of the layers from the Great Weigh House.