The Early Oceans

The Early Oceans

1. AS the Earth cooled, water vapour in the atmosphere condensed and fell as rain to make the oceans.

2. Carbon dioxide from the atmosphere dissolved into the oceans, causing the percentage in the atmosphere to drop.

3. Early sea plants used the dissolved carbon dioxide for photosynthesis, and released oxygen into the atmosphere.

4. Some sea animals took in carbon dioxide to make their shells. Shells from dead animals collected on the sea floor and over many years turned into carbonate rocks.