Volcanic eruptions may have spurred first ‘whiffs’ of oxygen in Earth’s atmosphere

A new analysis of 2.5-billion-year-old rocks from Australia finds that volcanic eruptions may have stimulated population surges of marine microorganisms, creating the first puffs of oxygen into the atmosphere. This would change existing stories of Earth's early atmosphere, which assumed that most changes in the early atmosphere were controlled by geologic or chemical processes.

source https://www.sciencedaily.com/releases/2021/08/210826111724.htm