Precambrian - relative time from 4.6billion - 542 million years ago
(note: 542 million years ago is the time of the Cambrian explosion)
1. Hadean Eon 4.62-4.00 billion years ago
remarkable event is: Earth collision with Theia at 4.52 billion years ago
2. Archean Eon 4.00-2.50 billion years ago
remarkable: rock land forming, and bacteria evolving in sea between 3.5-2.8 billion years ago
3. Proterozic Eon (age of hidden life)
remarkable: the formation of Rodinia at 1.2 billion years ago and photosynthesis process initiation.