Geochemical anomalies of trace elements in unremediated soils of Mt. Karczowka, a historic lead mining area in the city of Kielce, Poland

摘要

Concentrations of selected trace elements (Ag, As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) and rare earth elements were determined in 61 samples of surface soils collected from Mt. Karczówka, a historic Pb ore mining area located in the city of Kielce, south-central Poland. Some of these samples were subjected to XRD analyses and Pb stable isotope measurements. The mineral and chemical composition of rock samples were also examined. Mining activity in the study area was conducted mostly during 15th-17th centuries using technologically primitive methods, and was finally ceased in the first half of the 19th century. More than three thousand old shafts, pits and adits occur in the study area and its vicinity. The soils of the study area have not been remediated since the end of the mining operations. The trace elements of the examined surface soils are heterogeneously distributed with lead concentrations in the range of 41-9114 mg/kg and Pb isotopic signatures similar to those of local galena. The results of trace element measurements allowed us to discriminate geochemical anomalies from background levels and to link mineralogy of the host rocks to the origin of anomalous element concentrations. This study shows that elevated levels of elements of geogenic origin have remained in surface soil for two centuries after cessation of mining operations.