pyroclastic

/ˌpaɪroʊˈklæstɪk/
adjective
  1. Relating to or consisting of fragments of rock and lava ejected by a volcanic eruption.
    • Scientists study pyroclastic deposits to learn about past eruptions.
    • The pyroclastic flow from the volcano destroyed everything in its path.
    • The hikers were warned about the danger of pyroclastic surges near the active crater.