archean

adjective

Meaning

Relating to the earliest eon of Earth's history, spanning from approximately 4 billion to 2.5 billion years ago.

Examples

  • The Archean eon is characterized by the formation of the first stable continental crust.
  • Scientists discovered fossilized microbial mats preserved within ancient Archean sedimentary rocks.

Synonyms: ancient, primeval, primordial, pre-Cambrian