pyroclastic

Noun

A rock mostly composed of rock fragments of volcanic origin

Japanese Meaning

火山起源の岩石断片から主に成る岩石、すなわち火山噴出物から構成された火山性岩石

The geologist carefully examined a pyroclastic to determine its formation history.

地質学者は生成史を解明するために、火山砕屑岩を慎重に調べた。

Sense（1）

A rock mostly composed of rock fragments of volcanic origin

The basic volcanics are altered andesites, porphyritic diabases and andesites, and various pyroclastics.

pyroclastics

（ plural ）