臼きゅう状じょう火か山ざん

noun

pyroclastic cone

A volcanic landform built from ejected fragments around a vent; a technical term in volcanology.

• 臼きゅう状じょう火か山ざんは、噴ふん火かで放ほう出しゅつされた岩がん片ぺんが積つもってできる。

  A pyroclastic cone is formed by the accumulation of rock fragments ejected during an eruption.