> planets are big, atmospheres are big, and life is small;
And time is long.
The consensus is still that the oxygenation of Earth's atmosphere took "at least 400 million years". A lot of that is due to the "great rust", i.e. minerals that would take oxygen out of the air had to first exhaust their capacity to oxidise. This took "nearly a billion years".
Iron ore deposits are from the seabed of this period.
And time is long.
The consensus is still that the oxygenation of Earth's atmosphere took "at least 400 million years". A lot of that is due to the "great rust", i.e. minerals that would take oxygen out of the air had to first exhaust their capacity to oxidise. This took "nearly a billion years".
Iron ore deposits are from the seabed of this period.
See:
https://en.wikipedia.org/wiki/Great_Oxidation_Event
https://en.wikipedia.org/wiki/Banded_iron_formation