ORIGIN OF ACCRETIONARY LAPILLI FROM THE POMPEII AND AVELLINO DEPOSITS OF VESUVIUS.

Accretionary lapilli from the Pompeii and Avellino Plinian ash deposits of Vesuvius consist of centimeter-sized spheroids composed of glass, crystal, and lithic fragments of submillimeter size. No recent detailed studies by modern techniques have been published on accretionary lapilli. We have used the scanning electron microscope (SEM) in conjunction with energy-dispersive spectral analysis (EDS) to investigate the textural and chemical variation along traverses from the core to the rim of lapilli from Vesuvius.