Eon Archean Eon

Time runs left (older) → right (younger) · Hover a card for details

First stable crust, earliest life, stromatolites (4031-2500 Ma).

4.03 Ga – 2.50 Ga · 1.53 Ga duration

Axis labels in Ma (millions of years ago) · Click a card for details

Archean Eon 4

4031 Ma – 4000 Ma Acasta Gneiss Oldest confirmed rocks on Earth The Acasta Gneiss of northwestern Canada (~4.0 Ga) are the oldest known intact crustal rocks.
3800 Ma – 3700 Ma First Life Earliest evidence of life Chemical signatures suggest life existed by at least 3.7 Ga, likely chemosynthetic bacteria near hydrothermal vents.
3500 Ma – 3000 Ma First Continents Cratons stabilise First stable continental nuclei (cratons) form, beginning long-term accumulation of continental crust.
3500 Ma First Stromatolites Photosynthetic mats appear Layered structures built by cyanobacterial mats — oldest confirmed photosynthetic life, found in Pilbara, Australia.