Ejecta

Mt. St Helens eruption plume on 22 July 1980, showing ejecta in the form of pyroclastic material (ash)

Ejecta (from Latin 'things thrown out'; singular ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials (tephra) that came out of a volcanic explosion and magma eruption volcanic vent, or crater, has traveled through the air or under water, and fell back on the ground surface or on the ocean floor.