Ancient mineral particles may have fuelled the rise of Earth’s oxygen

The research offers a new understanding of how O2 became abundant in Earth’s atmosphere and provides a glimpse into the conditions needed for complex life to develop in distant worlds. 

Researchers from the University of Leeds argue that as the algae and plants perished, they would have been eaten by microorganisms. This process, known as decomposition, depletes the atmosphere of O2. 

Assuming the total atmospheric O2 is a balance between this depletion and photosynthesis (where O2 is gained), the researchers believe the former process must have been reduced or stopped for its levels to rise.

They claim that this was made possible by a process known as mineral-organic carbon preservation. Simply put, this happens when iron-containing minerals from the oceans attach to dead algae and plants, preventing them from decomposing. The overall outcome allowed O2 levels to rise unrestricted.

Light microscope image of marine organic matter collected with a plankton net

 “Scientists have known for many years that mineral particles can bind with dead algae and plants…shielding them from the decay process,” said lead author Professor Caroline Peacock in a press release.

“But whether mineral particles helped fuel the rise of atmospheric oxygen had never been tested,” she explained.