Definition of pyroclastic in English:

pyroclastic

adjective

Geology
  • Relating to, consisting of, or denoting fragments of rock erupted by a volcano.

    ‘pyroclastic material’
    • ‘In practice pyroclastic and volcaniclastic rocks include all the products of extrusive volcanic activity except lava flows.’
    • ‘Two main types of pyroclastic surges occurred at Taapaca Volcanic Complex.’
    • ‘Stratovolcanoes are formed of alternating layers of pyroclastic materials and subordinate lavas.’
    • ‘Samples of pyroclastic rocks were examined in thin section.’
    • ‘Erosion of old lava dome complexes has resulted in deep valleys that dissect pyroclastic and volcanoclastic fans.’

plural noun

Geology
  • Pyroclastic fragments.

    ‘the eruption of lavas and pyroclastics’
    • ‘Voluminous quantities of Late Ordovician to Wenlockian felsic pyroclastics and lava flows record the extensive volcanism associated with the collision and deformation.’

Pronunciation:

pyroclastic

/ˌpʌɪrə(ʊ)ˈklastɪk/