Mineralogical and geochemical spatial analyses of a waste-rock dump at the Libiola Fe–Cu sulphide mine (Eastern Liguria, Italy)

• Published in: Environmental earth sciences 2010-07, Vol.61 (1), p.187-199
• Main Authors: Marescotti, Pietro, Azzali, Eva, Servida, Diego, Carbone, Cristina, Grieco, Giovanni, De Capitani, Luisa, Lucchetti, Gabriella
• Format: Article
• Language: English
• Subjects: Acid mine drainage; Acidification; Acidity; Basalt; Biogeosciences; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental perception; Environmental Science and Engineering; Exact sciences and technology; Geochemistry; Geology; Geostatistics; Hydrology/Water Resources; Lithology; Mineralogy; Mines; Original Article; Pollution, environment geology; Pyrite; Rocks; Spatial analysis; Sulfides; Terrestrial Pollution
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-009-0335-7

In this work, we investigated a 3 ha sulphide-bearing waste-rock dump (Libiola Mine, Italy) using mineralogical, geochemical, and geostatistical analyses. The dumped materials were highly heterogeneous in grain size and lithology and varied both laterally and vertically. Other than the host rock of the ore, basalts and serpentinites, the dumped materials contained high amounts of low-grade chalcopyrite- and pyrite-rich mineralisations. Due to these characteristics and to the absence of minerals able to neutralise acidity, this waste-rock dump can be classified as an acid mine drainage (AMD) producer. The study confirms that AMD is still active and, in the best scenario, can persist for up to 6.17 × 10 3 years. The consequences of this process are of serious environmental concern as it involves strong acidification of the circulating waters, the release of potentially toxic metals into the soil, streams and rivers and the precipitation of huge quantities of secondary Fe-oxides and Fe-oxyhydroxides.