Proterozoic ocean chemistry and evolution: a bioinorganic bridge?

Abstract in brief

• During the Proterozoic Eon, Earth's oceans were generally oxygen-rich at the surface but contained sulfide-rich, or euxinic, conditions at depth, impacting marine chemistry.
• These redox conditions likely caused a shortage of vital trace metals in the oceans, which could have limited processes like nitrogen cycling, primary productivity, and the spread of eukaryotic algae.
• Understanding these ocean chemistry and redox dynamics helps explain key patterns in Earth’s biological and evolutionary history during the Proterozoic period.]