Definitions for "Tephra"
A general term for pyroclastic material ejected from a volcano. It includes ash, dust, bombs, and other types of fragments.
volcanic ash. In the Mediterranean, for example, deep-sea coring produced evidence for the ash fall from the eruption of Theta, and its stratigraphic position provided important information in the construction of a relative chronology.
The name given to pyroclastic materials of all shapes and sizes.