Researchers have proposed a new theory for how oxygen production was kick-started billions of years ago, when only trace amounts of the gas existed in the Earth’s atmosphere. When continents collided they started a chain reaction, researchers say, that eventually produced a hospitable, oxygen-rich atmosphere. They argue that the tectonic collisions that created the Superia/Sclavia, Nuna, Rodinia, Gondwana and Pangaea supercontinents also formed supermountains, which eroded rapidly, washing vast amounts of nutrients into the oceans. This fuelled explosions of oxygen-producing algae and bacteria [New Scientist].
The Australian researchers say that each collision of tectonic plates caused a bump in oxygen levels, and that studies of modern mountain formation bear out their theory. Other scientists have already shown that the formation and erosion of the Himalayas led to increases in atmospheric oxygen, [study coauthor Charlotte] Allen notes. “Scale up the Himalaya to supercontinental proportions and you have a modern analogue for what we think happened seven major times in earth’s history” [ABC Science]. However, some experts have expressed skepticism regarding the new theory.
