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