text: is it pyroclastic or pyroplastic?   both. also in music ... runt. pioneers of the pyroplastic flow.: 5 piece band from buffalo, ny. provides a biography, pictures, news, and contact information.  ceramic plant personnel, ceramic engineers, ceramic artists, and potters involved with whiteware glaze formulations, glaze development, traditional ceramic body development, firing issues, and pyroplastic deformation.  pyroclastic flows are a common and devastating result of some volcanic eruptions. they are fast-moving fluidized bodies of hot gas, ash and rock (collectively known as tephra) which can travel away from the vent at up to 150 km/h.  the definition of "pyroclastic eruption" is: "lateral flowage of a turbulent mixture of hot gases and unsorted pyroclastic material (volcanic fragments, crystals, ash, pumice, and glass shards) that can move at high speed (50 to 100 miles an hour.) the term also can refer to the deposit so formed." (total of 9 images)