Consecuencias hidrogeológicas del cese de actividades mineras. El caso del

Abstract

The general drainage gallery of the Linares mining district was designed to minimize elevation cost from dewatering the deepest levels of the underground works. Following the mining closure and the flooding of the mining voids, this gallery (the so-called "socavón") is draining by gravity groundwater resources of the Linares batolith. In addition, an exploitation of these resources is taking place by pumping directly from old shafts, some of them connected through the gallery. The gallery discharge has been monitored during a year as well as the physico-chemical characteristics of the water. The flow averages 60 I/s and both the electrical conductivity and temperature of the water are quite stable. Flow variations suggest a relatively quick response to the infiltration inputs as well as the effect of pumpings. E.C. values point out to an homogeneous process of mineralisation of groundwater, which can be attributed to sulphide oxidation buffered by carbonates. The groundwater balance of the batolith is at present equilibrated. The increasing in pumping is likely to be accompanied by the progressive exhaustion of the gallery flow