Existing comment:
ANCIENT STROMATOLITES BUILT BY CYANOBACTERIA AND BANDED IRON
You can touch rocks that were formed by some of Earth's oldest life. The larger stromatolite is 2.7 billion years old, while the smaller one is 2.3 billion years old. Their ages bracket the Great Oxidation Event (GOE). On the reverse side is a banded iron sample (2.45 billion years old). |