ABSTRACT

Aerosols were sampled at Mount Etna over a five-month period in 1985, enclosing the March-July south upper flank eruption. Collection was performed both at effusive vents by manual sampling during the eruption, and in the summit plume by means of an automatic collector during and after the eruption. The automatic collector allows a regular sampling in the difficult-to-reach summit area. Aerosols were analysed for S, Cl, and some metallic elements by 3 complementary analytical techniques (XRF, PIXE and AAS). Aerosol mineralogy has also been investigated by means of SEM. The analysed elements are emitted with enrichments coherent with the known models dealing with their degree of volatility in magmatic conditions. Sulfuric acid-particle reactions in the summit plume and high-temperature fractionation phenomena cause large discrepancies in the mineralogy and chemistry of particles emitted from the summit craters and lateral vents.