Dispersion of metal(loid)s in fluvial sediments: an example from the Linares mining district (southern Spain).

A study of the trace elements distribution in sediments along the main watercourse of the Linares mining district (Jaen, Spain) was carried out. For this purpose, 56 soil samples were collected in the stream channel and floodplain. To obtain a geochemical characterisation of the soil, the pH, organic matter and the silt-clay fraction were measured and 33 elements were analysed. The results derived from these measurements were studied statistically and compared to the reference values for soils standards under two different regulations. This made it possible to recognise the dispersion patterns of the different metals and metalloids associated with the old mining activity of the district and to characterise the effects of the various pollution sources along the watercourse. An elevated Pb content was detected, which was associated with tailings ponds and waste rock dumps. Similarly, high concentrations of As in sediments were identified, which were associated with a smelter located at the headwater of the catchment area. [ABSTRACT FROM AUTHOR]