The formation of the early ocean played a large part in shaping what gases remained in the atmosphere and what gases were carried into the water, to become dissolved into the ocean and surface reservoirs. Scientists think that the Earth's secondary atmosphere may have come to be dominated by N2 because it alone of all the gases comprising the secondary atmosphere does not readily dissolve in water.
Meanwhile, about this time, it is thought that life may have begun on Earth. The early ocean became the repository of many of the waste products of the activity of early life on Earth. Such waste products included iron in the form of pyrite. Pyrite was the result of early bacteria making food for itself along sulphur pathways.
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