Historical Record of Magnetic and Geochemical Signals in Mountain Peat Bogs: A Case Study of the Black Triangle Region (the Izery Mountains, SW Poland)

Peat bogs are effective archives of magnetic particles. The diamagnetic properties of organic matter with a zero or slightly negative value of magnetic susceptibility provide an excellent background to even small amounts of magnetic particles associated with anthropogenic activity. To the best of our knowledge, this is the first record of the technogenic magnetic particle (TMP) and potentially toxic element (PTE) contamination derived from peat archives of the study area. The investigated ombrotrophic peat bog in a historically heavily industrialized area provides an excellent starting point for future studies on the magnetic recorder and/or long-term stability properties of peatlands as archives of industrial activities. The main aim of this work was to assess the extent of overlap between the accumulation of TMPs with PTEs and iron in the peat profile and the periods of anthropogenic activity, using radiocarbon (C) and lead (Pb) dating methods. In peat profiles, an enrichment in PTEs and iron was observed, corresponding to the period of maximum exploitation of lignite and lignite-based power plants in the “Black Triangle” region, as well as the exploitation of metal ores from the eighteenth century to the end of the 1990s in the twentieth century. Local influences related to the operation of the nearby glasswork and the exploitation of local tin and uranium ores were recorded in the peat layers corresponding to the time span 1774–1879 in the form of increased concentrations of As, Cu, Fe, Pb, Se, Sn, Th, Ti, U, and Zr.