Lapilli

Lapilli (sg.: lapillus) is a size classification of tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. Lapilli is Latin for "little stones". It consists of fresh pumice or scoria, volcanic glass such as Pele’s hair, lithic fragments of rock or crystal or as ash aggregates such as accretionary lapilli, cored accretionary lapilli, ash pellets or ash coated clasts.

By definition lapilli range from 2 to 64 mm (0.08 to 2.52 in) in diameter. A pyroclastic particle greater than 64 mm in diameter is known as a volcanic bomb when molten, or a volcanic block when solid. Pyroclastic material with particles less than 2 mm in diameter is referred to as volcanic ash.

This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.