Question

What does the presence of rust develops an ancient ocean show? Pick one answer

Oxygen from the earths atmosphere dissolved into the oceans

Anaerobic organisms decreased

Oxygen levels in the sea increased due to photosynthetic bacteria

Oxygen from space traveled into the earth of atmosphere

Answers

GPT-4o mini
The presence of rust developing in an ancient ocean shows that **oxygen levels in the sea increased due to photosynthetic bacteria**. Rust, primarily iron oxide, forms in the presence of oxygen, indicating that there was enough dissolved oxygen in the water, which is typically linked to the activity of photosynthetic organisms.