Volcanic activity and changes in Earth's mantle is the key to the rise in atmospheric oxygen

June 14, 2020

Roughly 2.4 billion years ago the whole enchilada for Earth changed. It was the time of the Great Oxidation Event (GOE) when photosynthetic bacteria swamped the atmosphere with oxygen and allaying the non- oxygen using organisms to the rim of the Earth.
But there is a perplexing detail about this span which puzzled the scientists. Photosynthetic bacteria were pumping out oxygen long before GOE (hundreds of millions of years before). 
Where did all the oxygen go?
A neoteric study examined this question. The lead author is Shintaro Kadoya, a postdoctoral researcher in Earth and Space Sciences of the University of Washington. The study is entitled " Mantle data imply a decline of oxidizable volcanic gasses could have triggered the Great Oxidation '' It's published in the journal Nature Communications.
The earth's atmosphere, mantle, and life are entangled. 
As living entities appeared on the surface of the Earth, they set off oxygen as a by-product of metabolism. At the outset, oxygen didn't accumulate in the atmosphere. That's due to the volcanoes and the materials it brought up from the mantle. Previously mantle used to release lots of gases mainly hydrogen. Oxygen is highly reactive and doesn't hesitate to combine with hydrogen. This happened with many other gases and materials. Eventually, decreasing the oxygen content in the atmosphere. Hence, those life forms were in a battle of their own.
The 2019 study based on volcanic rocks in Canada and South Africa that were 3.55 billion years old revealed that as time passed, Earth's mantle has become more oxidized.
The recent study involving 2019 researched stated from the evidence collected from the sedimentary rock shows that 2.5 billion years ago, the volcanic cycle had oxidized more materials from the mantle. The ongoing volcanic processes it produced as fewer materials that fused with oxygen. Soon Earth's mantle became more and more oxidized, the oxygen generated by the organisms stored up in the atmosphere.
The mantle, once devoid of any oxygen, was now becoming the reservoir of the same. The oxygen furnished had nowhere except the atmosphere to pile upon. Thus, the Great Oxidation was set forward and cleared the deck for intricate life processes.


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