1. Plural of ignimbrite; rock formations composed of volcanic ash, pumice, and rock fragments that were deposited by fast-moving pyroclastic flows.
Usage: geology; technical term; typically used in plural or as a mass noun

Examples

• The ignimbrites in the volcanic region show evidence of extreme heat and pressure during deposition.
• Geologists studied the ignimbrites to understand the eruption history of the ancient volcano.
• These ignimbrites contain pumice fragments that indicate a violent explosive eruption.
• The thick layers of ignimbrites suggest multiple pyroclastic flow events occurred in succession.
• Ignimbrites are commonly found in areas with a history of caldera-forming eruptions.