Atmospheric sources and sinks of volcanogenic elements in a basaltic volcano (Etna, Italy) S. Calabrese a,⇑ , A. Aiuppa a,b , P. Allard c , E. Bagnato a , S. Bellomo b , L. Brusca b , W. D’Alessandro b , F. Parello a a Dipartimento di Scienze della Terra e del Mare (DiSTeM), Universita ` di Palermo, via Archirafi 36, 90123 Palermo, Italy b Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, via La Malfa 153, 90146 Palermo, Italy c Institut de Physique du Globe, Sorbonne Paris Cite, 1 rue Jussieu, 75238 Paris Cedex 05, France Received 28 November 2010; accepted in revised form 14 September 2011 Abstract This study reports on the first quantitative assessment of the geochemical cycling of volcanogenic elements, from their atmospheric release to their deposition back to the ground. Etna’s emissions and atmospheric depositions were characterised for more than 2 years, providing data on major and trace element abundance in both volcanic aerosols and bulk depositions. Volcanic aerosols were collected from 2004 to 2007, at the summit vents by conventional filtration techniques. Precipitation was collected, from 2006 to 2007, in five rain gauges, at various altitudes around the summit craters. Analytical results for volcanic aerosols showed that the dominant anions were S, Cl, and F, and that the most abundant metals were K, Ca, Mg, Al, Fe, and Ti (1.5–50 lgm 3 ). Minor and trace element concentrations ranged from about 0.001 to 1 lgm 3 . From such analysis, we derived an aerosol mass flux ranging from 3000 to 8000 t a 1 . Most analysed elements had higher concen- trations close to the emission vent, confirming the prevailing volcanic contribution to bulk deposition. Calculated deposition rates were integrated over the whole Etna area, to provide a first estimate of the total deposition fluxes for several major and trace elements. These calculated deposition fluxes ranged from 20 to 80 t a 1 (Al, Fe, Si) to 0.01–0.1 t a 1 (Bi, Cs, Sc, Th, Tl, and U). Comparison between volcanic emissions and atmospheric deposition showed that the amount of trace elements scav- enged from the plume in the surrounding of the volcano ranged from 0.1% to 1% for volatile elements such as As, Bi, Cd, Cs, Cu, Tl, and from 1% to 5% for refractory elements such as Al, Ba, Co, Fe, Ti, Th, U, and V. Consequently, more than 90% of volcanogenic trace elements were dispersed further away, and may cause a regional scale impact. Such a large difference between deposition and emission fluxes at Mt. Etna pointed to relatively high stability and long residence time of aerosols in the plume. Ó 2011 Elsevier Ltd. All rights reserved. 1. INTRODUCTION The anthropogenically perturbed biogeochemical cycles of trace elements are contributed by a variety of natural sources, among which volcanic degassing clearly stands out (Nriagu, 1989). It is no doubt that volcanic emissions are important sources of metal-bearing gases and particles into the atmosphere (Cadle, 1980; Nriagu, 1989; Hinkley et al., 1999; Oppenheimer, 2003; Mather et al., 2003), as demonstrated by metal output inventories evaluated for a number of volcanoes, including Kilauea (Cadle et al., 1973; Crowe et al., 1987; Hinkley et al., 1999), Etna (Buat-Me ´nard and Arnold, 1978; Quisefit et al., 1982; Bergametti et al., 1984; Pennisi et al., 1988; Andres et al., 1993; Toutain et al., 1995; Gauthier and Le Cloarec, 1998; Aiuppa et al., 2003; Allen et al., 2006; Bagnato 0016-7037/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.gca.2011.09.040 ⇑ Corresponding author. Tel.: +39 3494266907; fax: +39 0916168376. E-mail addresses: sergio.calabrese@gmail.com, sergio. calabrese@unipa.it (S. Calabrese). www.elsevier.com/locate/gca Available online at www.sciencedirect.com Geochimica et Cosmochimica Acta 75 (2011) 7401–7425