| << Chapter < Page | Chapter >> Page > |
Card 18 / 19:
stromatolites
solid, layered rock formations that are thought to be the fossils of oxygen-producing photosynthetic bacteria in rocks that are 3.5 billion years old
| Previous Card | ← Previous Card Button |
| Next Card | → Next Card Button |
| Flip Card | ↑ / ↓ / Return / Space |
Notification Switch
Would you like to follow the 'Astronomy' conversation and receive update notifications?
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|