第だい四よん紀き

noun

Quaternary period

Geological term for the most recent period of the Cenozoic era, spanning from about 2.58 million years ago to the present.

• 第だい四よん紀きは氷ひょう河が時じ代だいとも呼よばれる。

  The Quaternary period is also called the Ice Age.

• 第だい四よん紀きの地ち層そうから多おおくの化か石せきが発はっ見けんされている。

  Many fossils have been discovered from Quaternary strata.