It is believed that the Earth's atmosphere is initially white, anoxic, and about 2.43–2.45 billion years oldBack
In order to clarify these data, researchers from the United States, Great Britain and Denmark analyzed the composition of marine sedimentary rocks from South Africa, dating back to the Paleoproterozoic — from2.5 to 1.6 billion years.
Next, they reconstructed changes in redox conditions in the ocean of that period from isotopic signatures of sulfur, iron, and carbon to determine oxygen levels in the ancient atmosphere.
It turned out that the initial enrichmentoxygen occurred about 2.43 billion years ago. But then O2 levels fell and rose again and again before becoming a permanent component of the Earth's atmosphere about 2.22 billion years ago.
These findings help explain four widespread glaciations that occurred at the same time as the Great Oxidation Event, some of which likely covered the entire Earth with ice for millions of years.
Research text
Read more
The first accurate map of the world was created. What's wrong with everyone else?
Researchers plunged for the first time to the deepest sunken ship
Algorithm has discovered a new mysterious layer inside the Earth