extrusive

/ɪkˈstruːsɪv/ (bre, ipa) · /ɪkˈstruːsɪv/ (ame, ipa) · /ik-ˈstrü-siv -ziv/ (ame, mw)

extrusive — adjective

  • extrusivepositive
  • more extrusivecomparative
  • most extrusivesuperlative

1. describing rock that reaches the planet's surface as hot liquid through volcanic

1.形容詞B2
釋義

describing rock that reaches the planet's surface as hot liquid through volcanic activity, then cools into solid stone.

例句

The dark cliffs along Iceland's coast formed from extrusive volcanic rock.

collocation: extrusive volcanic rock

Lava flowing from the Kīlauea volcano turns into extrusive stone as it cools.

同義詞
  • volcanic

    broader term — all extrusive rock is volcanic, but volcanic can also describe eruptions, ash, and gases

  • effusive

    more specific — describes lava that flows out gently rather than exploding; used interchangeably in volcanology for certain rock types

  • eruptive

    emphasises the eruption process rather than the rock's final location

反義詞
  • intrusive

    describes magma that cools and solidifies below the Earth's surface, forming rocks like granite

  • plutonic

    a more specific term for intrusive rock that forms in large underground chambers

文法句型

extrusive + noun (rock, material, stone)

用法筆記

Frequently appears before nouns describing types of stone or volcanic material (extrusive rock, extrusive igneous rock). The opposite term is intrusive, which describes magma that cools slowly below ground.

常見錯誤

❌This extrusive rock came from deep inside the volcano's magma chamber.
✅This extrusive rock formed from lava that reached the surface.
💡Extrusive rock solidifies above ground, NOT inside the volcano.