Pyroclastic

Pronunciation

• Rhymes: -æstɪk

Origin

From - clastic, from Ancient Greek πῦρ (pur, "fire"), and κλαστός (klastos, "broken").

Full definition of pyroclastic

Adjective

1. (vulcanology) Mostly composed of rock fragments of volcanic origin or comminuted during an eruption.
• 1862, w, The Student's Manual of Geology Chapter Igneous Rocks, The word "ash" is not a very good one to include all the mechanical accompaniments of a subaerial or subaqueous eruption, since ash seems to be restricted to a fine powder, the residuum of combustion. A word is wanting to express all such accompaniments, no matter what their size or condition may be, when they are accumulated in such mass as to form beds of "rock." We might call them perhaps "pyroclastic materials," ...

Derived terms

• pyroclastic flow
• pyroclastic rock
• pyroclastic surge

Noun

1. A rock mostly composed of rock fragments of volcanic origin
• 1897, , The American Naturalist: An Illustrated Magazine of Natural History Chapter General Notes: Geology and Paleontology, The basic volcanics are altered andesites, porphyritic diabases and andesites, and various pyroclastics.