Remember Tephra
Tephra Technical Terms
Tephra: A collective, general term for any and all clastic materials, regardless of size or composition, ejected from a vent during a volcanic eruption and transported through the air; including ash [volcanic; < 2 mm], blocks [volcanic; > 64 mm], cinders [volcanic; 2 – 64 mm], lapilli [2 - 76 mm & specific gravity > 2.0], pumice [> 2 mm & specific gravity < 1.0], and scoria [> 2 mm & specific gravity < 2.0]. Tephra, unlike many volcaniclastic terms, does not denote properties of composition, vesicularity, or grain size. SW