Both life and geological processes get their start in the Archaean era amidst a brew of atmospheric gases that probably includes methane and ammonia but little or no free oxygen. As Earth cools ...

In the Archean, long before rooted land plants were ... Low-latitude glaciations in the Paleoproterozoic era. Nature 386, 262–266 (1997). Farquhar, J., Bao, H. & Thiemans, M.

Scientists think that the very first continents formed between 2.5 billion and 4 billion years ago, during the Archean period. To study this period, researchers often examine rare mineral deposits ...