pyroclastic

American  

[pahy-ruh-klas-tik] / ˌpaɪ rəˈklæs tɪk /

adjective

Geology.

1. composed chiefly of fragments of volcanic origin, as agglomerate, tuff, and certain other rocks; volcaniclastic.

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pyroclastic British  

/ ˌpaɪrəʊˈklæstɪk /

adjective

1. (of rocks) formed from the solid fragments ejected during a volcanic eruption

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pyroclastic Scientific  

/ pī′rō-klăs′tĭk /

1. Composed chiefly of rock fragments of explosive origin, especially those associated with explosive volcanic eruptions. Volcanic ash, obsidian, and pumice are examples of pyroclastic materials.

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Etymology

Origin of pyroclastic

First recorded in 1885–90; pyro- + clastic

Example Sentences

The rise and collapse of the eruption column presaged a series of pyroclastic surges, the fourth of which killed everyone in its path in Pompeii.

From The Wall Street Journal • Jan. 2, 2026

The temperature of the pyroclastic flows that buried Herculaneum and Pompeii was several hundreds of degrees Celsius, hot enough to easily burn and destroy soft tissue.

From Salon • Mar. 4, 2025

Experts believe the ash cloud turned the man's brain into glass because the pyroclastic flow would not have reached high enough temperatures or cooled quickly enough.

From BBC • Feb. 27, 2025

Researchers interpret the volcano to be a vast shield made of layered accumulations of pyroclastic materials, lavas, and ice, the latter resulting from repeated buildups of snow and glaciers on its flanks through time.

From Science Daily • Mar. 13, 2024

The pyroclastic surge, Jess realized, the fiery hurricane wind packed with poisonous gas and ash.

From "I Survived the Eruption of Mount St. Helens, 1980" by Lauren Tarshis