Magnetometry and ground-penetrating radar surveys applied to tracing potential collectors of mining-derived pollutants in coastal sediments (Piscinas Bay, Montevecchio mining area, SW Sardinia)
Dispersion of pollutants from mining areas can result in risks to human health. The dynamic interaction of geological processes can generate complex situations that favor enrichment in toxic elements by sedimentary and diagenetic mechanisms. In order to explore the distribution of iron-rich minerals in coastal and river sediments, a geophysical campaign was performed along the outlet of the Piscinas and Naracauli Rivers that drain two abandoned mining areas in SW Sardinia. Both rivers flow into the Mediterranean Sea, a bay where fluvial, marine, and eolian processes interact. The geophysical campaign comprised magnetometry and ground-penetrating radar surveys. Magnetic properties were controlled by means of magnetic susceptibility measurements along the beach and dune areas, through sampling of surface sediments, natural outcrops and trenches, and considering different grain size intervals. Results indicate enrichment in ferromagnetic minerals at the leeside of dunes and berms. Sedimentological interpretation is supported by means of ground-penetrating radar. Due to both sedimentary and diagenetic processes, the 100- to 300-μm fraction of fine sands exhibits high susceptibility. Implied tenors of toxic elements in the magnetite may represent a serious hazard to environmental and health security. The results inferred from magnetic anomalies support the applicability of the geophysical approach in order to locate high concentrations of iron-rich particles both at surface and below ground and the usefulness of joint evaluation of magnetic susceptibility and ground-penetrating radar in order to characterize the sedimentary and geomorphology-controlled magnetite distribution.
KeywordsPotentially toxic elements Environmental magnetism Magnetometry Magnetic susceptibility Ground-penetrating radar Mining wastes Sardinia
This work has been supported by Università degli studi di Cagliari and Geotransfer Research Group from Universidad de Zaragoza. Authors want to acknowledge suggestions from three anonymous reviewers.
- Alloway BJ (1990) Heavy metals in soils. John Wiley and Sons Inc, New YorkGoogle Scholar
- Biddau R, da Pelo S, Dadea C (2001) The abandoned mining area of Montevecchio-Ingurtosu. Rend Semin Fac Sci Uni Cagliari 71(fasc. 2):109–123Google Scholar
- Cavinato A, Zuffardi P (1948) Geologia della miniera di Montevecchio. Notizie sull’industria del Piombo e dello Zinco in Italia, 1. Montevecchio Società Italiana del Piombo e dello Zinco, pp 427–464Google Scholar
- Chessa A, Fanfani L, Zuddas P (1995) Heavy metal speciation in abandoned mine tailings. In: Wilken RD, Forstner U, Knockel, A (Eds) International conference on heavy metals in the environment. Hamburg. CEP Consultants, Edinburgh, pp 5–8Google Scholar
- Cornell R, Schwertmann U (2003) The Iron Oxides. Structure, properties, reactions, occurrence and uses. 2nd edn. Wiley VCH, GmbH&Co, KGaAGoogle Scholar
- Di Gregorio F, Ferrara C, Ibba A (1997) Geoenvironmental characteristic and human impact in a transitional system in SW Sardinia (Italy). In: 6th EUCC conference 2–6 June 1997, NaplesGoogle Scholar
- Dube A, Zbytniewski R, Kowalkowski T, Cukrowska E, Buszewski B (2001) Adsorption and migration of heavy metals in soil. Pol J Environ Stud 10(1):1–10Google Scholar
- Durza O, Dlapa P (2006) Lead contents and magnetic susceptibility in alluvial soils of Stiavnica brook. Contr. Geophys. and Geodesy, 36, SPEC.ISS., 81–88Google Scholar
- Gómez-García C, Martín Hernández F, López García JA, Martínez Pagán P, Manteca JOI, Carmona C (2015) Rock magnetic characterization of the mine tailings in Portman Bay (Murcia, Spain) and its contribution to the understanding of the bay infilling process. J Appl Geophys 120:48–59CrossRefGoogle Scholar
- Lilliu G (1986) Le miniere ed i minatori di Sardegna. Consiglio Regionale della Sardegna. Pizzi (ed), Milano, Cagliari 1986, pp 7–18Google Scholar
- Petrovsky E, Kapicka A, Jordanova N, Knab M, Hoffmann V (2000) Low-field magnetic susceptibility: a proxy method of estimating increased pollution of different environmental systems. Environ Geol 39(3–4):312–318Google Scholar
- Stara P, Rizzo R, Tanca GA (1996) Iglesiente e Arburese. In: EMSA (ed) Miniere e Minerali. Ente Minerario Sardo, CagliariGoogle Scholar