Volcanic smoke clouds

Particulate matter obtained from the smoke clouds associated with eruptions of the volcano Syrtlingur off the south coast of Iceland were examined using an AMR Probescope. This instrument provided information on the morphology and chemical content of individual micron-sized particles of the smoke. A variety of particle compositions were observed. They included particles containing primarily Si, Ca + Si, Si + Ca + Fe, Cr + S/Cl, Fe/Ni + Cl, etc. Both nickel and chromium were strongly evident even though these elements occur in trace quantities in the magma. Results are interpreted in terms of particle formation by a process of selective vaporization from the magma and subsequent condensation from the vapor phase.