What is the Great Oxygenation Event (GOE)?
Q: What is the Great Oxygenation Event (GOE)?
A: The GOE was the creation of free oxygen in our atmosphere, caused by cyanobacteria doing photosynthesis. It took place over a long period of time, from three billion years ago to about one billion years ago.
Q: How did the GOE happen?
A: Before the GOE, organic matter and dissolved iron chemically captured any free oxygen. When not enough iron remained to capture more oxygen, free oxygen accumulated in the atmosphere, which was the GOE.
Q: What were some consequences of the GOE?
A: Oxygen was toxic to most of Earth's anaerobic inhabitants at the time, so many became extinct. Free oxygen also reacted with atmospheric methane, a greenhouse gas, removing it and causing Huronian glaciation - perhaps the longest snowball Earth episode ever. Free oxygen has been an important part of our atmosphere ever since.
Q: What is stromatolites?
A: Stromatolites are layered structures formed by cyanobacteria that can be found in shallow water environments such as lagoons and tidal pools. They are created when bacteria trap sediment particles within their mucus layers and form mats on top of each other over time.
Q: How did photosynthesis affect Earth before and after the GOE?
A: Photosynthesis was making oxygen both before and after the GOE; however before it all free oxygen would be captured by organic matter or dissolved iron whereas afterwards some free oxygen could accumulate in our atmosphere due to lack of available iron for capturing it all anymore.
Q: When did this event take place?
A: The Great Oxygenation Event took place from three billion years ago to about one billion years ago.
