Sulfur Studies: Early Earth’s air was oxygen-poor

Analyses of ancient sulfide minerals and the modern organisms that create sulfides are giving scientists a better idea of what Earth’s atmosphere and oceans may have been like billions of years ago. The findings may also explain a paradox that has long puzzled solar astronomers.

In one of the new studies, scientists looked at the ratio of isotopes in sulfide particles trapped in diamonds unearthed from a mine in Botswana.