archaean

¹

/ ɑːˈkɪən /

noun

1. any member of the Archaea , a domain of prokaryotic microorganisms, distinguished from bacteria on molecular phylogenetic grounds and often found in hostile environments, such as volcanic vents and hot springs

Archaean

²

/ ɑːˈkiːən /

adjective

1. of or relating to the highly metamorphosed rocks formed in the early Precambrian era
2. the earlier of two divisions of the Precambrian era, during which the earliest forms of life are assumed to have appeared

Example Sentences

Some of the metamorphic rocks may belong to the older Palaeozoic period, but the greater part of the series is probably Archaean.

From Project Gutenberg

They are known to be pre-Jurassic, but whether they are Palaeozoic or Archaean is uncertain.

From Project Gutenberg

They appear in contact with Archaean, Algonkian or early Palaeozoic rocks.

From Project Gutenberg

The Archaean rocks still solidly underlie the lowest depth he has ever reached.

From Project Gutenberg

As we have no recognisable remains of the animals and plants of the earliest age, we will not linger over the Archaean rocks.

From Project Gutenberg