David Denner discussed the composition of the earth's primitive atmosphere as advocated by evolutionists. He concluded that 'the reason for the widespread adherence to the belief in a primitive reducing atmosphere, in spite of much evidence to the contrary, is the same reason for which it was postulated. If you are to believe many of the theories of chemical evolution at all, you simply have to believe the earth's atmosphere was once radically different from its composition today.
Most geologists accept the assertion that the early earth had a reducing atmosphere.
Lack of obvious Archaean life has popularly been attributed to a hostile environment rich in toxic, reduced volcanic gases. Lack of Archaean sulphates and red beds has similarly been attributed to peculiar atmospheric and hydrospheric compositions. However, there is now substantial evidence against these interdependent concepts. They went on to explain that 'the sedimentary distributions of carbon, sulphur, uranium, and ferric and ferrous iron depend greatly upon ambient oxygen pressure and should reflect any major change in proportion of oxygen in the atmosphere or hydrosphere. The latter is termed organic carbon and is the decay product of living matter.