pyroclastic

adjective

py·​ro·​clas·​tic ˌpī-rō-ˈkla-stik 

: formed by or involving fragmentation as a result of volcanic or igneous action

Examples of pyroclastic in a Sentence

Recent Examples on the Web

The ash that fell closer to Spurr remained a hazard for years as it was picked up by strong winds. Closer to the volcano, the eruptions produced pyroclastic flows, lahars (mudflows) and lots of volcanic bombs. —Erik Klemetti, Discover Magazine, 23 Oct. 2024

The pair appeared to use the bedroom to hide from the falling pumice during the eruption, which occurred in 79 A.D., and the room's seal caused the pair to be crushed from the volcano's pyroclastic flow. —James Powel, USA TODAY, 13 Aug. 2024

The man and woman died as a result of being buried by hot gas and volcanic matter, also known as pyroclastic flow. —Karen K. Ho, ARTnews.com, 12 Aug. 2024

All evidence points to an earthquake hitting after the first phase of the eruption, but before the pyroclastic flows swept through the city, the researchers say. —Byalex Epshtein, science.org, 18 July 2024

Word History

Etymology

probably from pyro- + clastic

Note: The term was introduced by the English geologist Joseph Beete Jukes (1811-69) in The Student's Manual of Geology, new edition (Edinburgh, 1862), p. 68: "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 so as to form beds of 'rock.' We might call them perhaps 'pyroclastic materials'…." In the index pyroclastic is glossed as "broken from fire."

First Known Use

1862, in the meaning defined above