ignimbrite

American  

[ig-nim-brahyt] / ˈɪg nɪmˌbraɪt /

noun

Petrology.

1. a fine-grained volcanic rock consisting mainly of welded shards of feldspar and quartz.

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ignimbrite British  

/ ˈɪɡnɪmˌbraɪt /

noun

1. Also called: welded tuft.  a rock formed by the deposition at high temperature and the consolidation of a nuée ardente or other type of ash flow, being a complicated mixture of volcanic materials welded together by heat, hot gases, and pressure See tuft

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ignimbrite Scientific  

/ ĭg′nĭm-brīt′ /

1. A volcanic rock formed by the consolidation of volcanic ash and other material ejected by an explosive volcanic eruption.

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Etymology

Origin of ignimbrite

1932; < Latin ign ( is ) fire + imbr-, stem of imber rain, shower + -ite ¹

Explanation

Ignimbrite is a type of rock born from one of the most violent events on Earth: explosive volcanic eruptions. It forms when a fast-moving flow of hot ash, gas, and volcanic glass shards spreads across the ground and solidifies. The roots of the word ignimbrite include igni, meaning "fire," and imbr, meaning "rain" or "storm cloud." The -ite suffix is used in names of rocks and minerals. The geologist who named the rock in 1932 wanted to capture the terrifying nature of how these rocks form — raining down from a fiery cloud. The cloud is called a pyroclastic flow, and it rushes down a mountain as a scorchingly hot mixture of particles, dumping a thick layer of incredibly hot debris that fuses together into hard rock.

Example Sentences

So far, the team has found four previously unrecognized ignimbrite units at Sour Creek, suggesting at least four eruptive pulses.

From Scientific American • May 19, 2023

Groundmass crystallisation and cooling rates of lava-like ignimbrites: the Grey’s Landing ignimbrite, southern Idaho, USA.

From Nature • Dec. 12, 2017