Scientists Release Air Trapped 800 Million Years Ago
The team of scientists led by Nigel Blamey found tiny bubbles of air from around 800 million years ago trapped in samples of halite, which is the rock version of table salt. The scientists crushed the samples, releasing the air, which they ran through a machine called a quadrupole mass spectrometer.
The mass spectrometer measured the oxygen content of the prehistoric air and found that the air 800 million years ago was about 10 percent oxygen. This was five times higher than previously thought. Prior theories have estimated that until about 500 million years ago the air was relatively oxygen-free. Now it appears that oxygen was much more abundant much further back in the timeline, and scientists are not sure why.
