Comparative hydrochemical study in two sectors with abandoned metallic sulfide mines: Linares – La Carolina mining district (Jaén)

The Linares-La Carolina abandoned sulfide mines are partially flooded at present and the demand of water resources have led to the pumping of groundwater directly from the old shafts. There is a scarce mobilisation of heavy metals into the waters in the Linares area, which are characterized by net alkaline conditions (pH values from 6.7 to 8.2). Nevertheless, acid mine drainage is detected in La Carolina mining district, where pH values range from 3.4 to 7.3 and mine waters are characterized by a wide range of mineralization (from 300 mS/cm to 5500 mS/cm, approximately). In addition, Fe and Mn reach tens of mg/l, not only in acid mine drainage adits but also in some alkaline waters. These different hydrochemical types are interpreted as being due to the influence of the particular lithologies and hydrodynamic conditions of these mine