The Great Oxygenation Event (NOE) began 2.4 billion years ago, during which, from a practical point of view, the amount of atmospheric oxygen changed from zero (thousandth of a percent) to almost the present amount. The level rose to 10 percent in about 400 million years. This event radically changed the direction in which life on Earth could continue to evolve, and that’s when the oxygen-breathing organisms began to gain ground. To this day, it is not clear what could have started this vital process for us. According to one idea (and this is well known), biology itself, many clues point to the fact that long ago, 3.8 billion years ago, there were single cells breathing oxygen, so something else was needed to give impetus to evolution. oxygen production.
at recent days, Chemical sciences According to a research result published in the journal, the decomposition of volcanic gases may have contributed to this transformation in addition to single-celled organisms at the time. The search was done by Chinese Academy of Sciences to explain.
In addition to biological processes, the decomposition of carbon dioxide and water molecules in the atmosphere also increases the amount of atmospheric oxygen, which requires the power of ultraviolet radiation from the sun. Chinese researchers have now come to the conclusion that it is also possible to produce oxygen by breaking down volcanic sulfur dioxide using a recently completed device. Based on geological data, this gas was abundant, moreover, these geological traces also show that a significant photochemical effect (chemical effects caused by light) affected sulfur dioxide at that time, but this process of creating atmospheric oxygen was not taken into account account in mind so far.
According to calculations, larger “pulses” of sulfur dioxide, which are short-lived on a geological time scale, were required in order to create a large amount of oxygen, which would have been ensured by significant volcanic activity. Atmospheric conditions that lasted for a short time and concentrated in areas smaller and richer in oxygen than at the time may have been present on several occasions. The researchers concluded from their experiments that as a result of these processes up to 4.3 percent of our current oxygen level could have been created, but volcanic eruptions at that time would have been much richer in sulfur dioxide, so this is just minimum value.
These periods of a few months or years are the ones that can leave traces even in pre-NOE rocks. The researchers believe that these small, oxygen-rich periods could have started NOE, especially if the tectonic situation at that time, which led to significant volcanic activity, was also taken into account.
This discovery may also have consequences for other planets, so this process must also be taken into account when studying the planet’s atmosphere.
