Once oxygen started to be manufactured by cyanobacteria, why did it take so long to build up to significant levels?
A) initially most of the oxygen escaped into space
B) oxidation of surface rock and ocean minerals occurred
C) initially most of the oxygen produced dissolved in the oceans
D) initially most of the oxygen was converted into water by reaction with hydrogen

Question

Quizplus · Accepted Answer

As the first oxygen produced by cyanobacteria reacted with and oxidized surface rock and minerals in the oceans, it took a long time for the oxygen to build up to significant levels in the atmosphere. This process is known as the Great Oxidation Event and is thought to have taken several hundred million years. Oxygen escaping into space or being converted into water by reaction with hydrogen was not significant factors in the slow buildup of atmospheric oxygen. Some of the oxygen produced initially dissolved in the oceans, but this alone did not explain the slow buildup.

Once Oxygen Started to Be Manufactured by Cyanobacteria, Why Did