Investigation of contaminant metal dispersal from a disused mine site at Tyndrum, Scotland, using concentration gradients and stable Pb isotope ratios

Results are presented for a study of Pb and Zn concentrations and stable Pb isotope ratios for mining wastes, river sediments and 210Pb-dated peat cores from the vicinity of a derelict Pb/Zn mine at Tyndrum in central Scotland. Mining was carried out at Tyndrum between 1741 and 1862 and the original waste dumps were reworked between 1916 and 1925. Little remains of the original buildings and workings and the contemporary distribution and dispersion pathways of the residual waste are poorly defined. The mine and ore processing waste dumps were readily identified as highly polluted, barren areas, with concentrations of up to 21 and 3.4% Pb and Zn, respectively. The Pb in the waste was characterised by a 206Pb/ 207Pb atom ratio of 1.146±0.004 and a 208Pb/ 207Pb ratio of 2.432±0.007. Significant quantities of waste were also found along riverbanks and in river channel sediments in the vicinity of the mine, with concentrations of up to 5.22% Pb and 2.35% Zn. Concentrations of Pb and Zn in river channel sediments decreased markedly with increasing distance downriver from the mining area. However, the decrease in Pb concentrations in the