Abstract

Usagre (Badajoz, SW Spain) mercury mine was active for an undetermined time until its closure in 1971. The ore exploited in this mine was cinnabar (red HgS), and metallurgy was also performed locally by means of primitive furnaces of the Bustamante type. Since the closure of the mine, reclamation measures have not been carried out at the site, and actual passives include a mine shaft, an accessible descending gallery and a mine dump adjacent to the descending gallery. In the work described here, data from two soil geochemistry surveys were combined and analysed. The surveys were separated by a period of 32years. Measurements of total gaseous mercury (TGM) in the underground mine and its surroundings were also considered. The soil geochemistry included mercury, lead, zinc and copper. The results indicate that soil pollution is mostly related to the trace mineralisations on the surface and they can therefore be interpreted as natural geochemical anomalies. TGM concentrations are extremely high inside the mine but are of very low concern outside the mine.