Question

85. What was the Great Oxygenation of the Precambrian and what was its cause? How could it have put the earth's climate into a period of global ice for hundreds of millions of years?

Answer 1

Great Oxygenation of the Precambrian :

Before getting towards the answer let me explain you what is actually Precambrian:

It is also known as the earliest part or the period of the earth history. As its name suggest 'PRE' - 'CAMBRIAN' means it was the era before the CAMBRIAN i.e. the period of the Phanerozoic eon.

Now coming back to the topic

The Great Oxygenation was the event when free oxygen particles were released into the atmosphere. This event occur due to respiration process of Cyanobacteria as we all know that Cyanobacteria undergoes Photosynthesis and releases Oxygen as a waste product.

This whole Apocalypse occurred approx 2.5 billion years ago when earth neither have any plant that undergoes aerobic Respiration nor the animals. It is believed that back at that time earth wasn't the same as it is now.Initially due to the limited amount of Cyanobacteria , oxygen that was produced by them formed the bond with iron but lately when there number increased iron could not cop up with the amount that was being produced!

This whole event resulted in the abundance of the oxygen level in the atmosphere. Some particles started reacting with methane to form carbon dioxide. As we all know that Methane is more potential Green house effecting gas i.e. It keeps the earth warmer, therefore when it started to combine with Oxygen it resulted in lowering the temperature of earth hence the earth climate changed into period of global ice.

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