There was a WHOLE LOT of oxygen being produced well prior to the GOE. However, when oxygen-producing organisms died and decomposed, the oxygen they'd produced was consumed. In order for oxygen to build up in the atmosphere due to photosynthesis, reduced organic material had to be buried and sequestered without decomposing (oxidizing) first.
Trust me, I have a background in this shit.
@1: Banded iron formations (results of that rusting) are pretty much the hallmark of the GOE.
Trust me, I have a background in this shit.
@1: Banded iron formations (results of that rusting) are pretty much the hallmark of the GOE.
Wikipedia: First Life (TV series)
Its currently only available on a Region 2 DVD (I got mine from Amazon UK - Scarecrow Video is not onto this one).