Definition of clastic in English:



  • Denoting rocks composed of broken pieces of older rocks.

    ‘a group of clastic sediments such as conglomerates’
    • ‘In contrast, the Cambrian clastic rocks are characterized by a paucity of these zircons, suggesting a significant difference between Neoproterozoic and Cambrian drainage systems.’
    • ‘The Allouez Conglomerate is composed mainly of red-colored clastic rocks with lesser amounts of sandstone and siltstone.’
    • ‘Mechanical deposition, by water or wind, produces clastic rocks composed of broken fragments, generally of silicate minerals and small pieces of rock: sandstones and conglomerates.’
    • ‘The upper unit consists of red continental clastic rocks of presumed Pcrmo-Triassic age, overlain by Triassic carbonate rocks.’
    • ‘No volcanic or clastic sedimentary rocks were obtained from Cavalli Seamount.’


Late 19th century: from French clastique, from Greek klastos ‘broken in pieces’.