MINERALOGY AND CHEMISTRY OF SOLID AEROSOLS EMITTED FROM MOUNT ETNA

Aerosols were sampled at Mount Etna over a five-month period in 1985, enclosing the March-July south upper flank eruption. Collection was pe rformed 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 technique s (XRF, PIXE and AAS). Aerosol mineralogy has also been investigated b y means of SEM. The analysed elements are emitted with enrichments coh erent with the known models dealing with their degree of volatility in magmatic conditions. Sulfuric acid-particle reactions in the summit p lume and high-temperature fractionation phenomena cause large discrepa ncies in the mineralogy and chemistry of particles emitted from the su mmit craters and lateral vents.