Ancient Ocean Chemistry Reveals Clues to Early Life and Great Oxidation Event

New research on 2.75-billion-year-old stromatolites from Zimbabwe provides insights into Earth's early marine environment before the Great Oxidation Event. Led by Dr. Ashley Martin from Northumbria University, a team discovered unusual nitrogen isotope patterns, suggesting a large ammonium reservoir in deep waters, brought to the surface by upwelling. This ammonium, a reduced form of nitrogen, likely supported microbial growth in oxygen-depleted oceans influenced by volcanic activity. The findings, published in Nature Communications, propose that volcanic activity may have fueled early life by providing bioavailable nitrogen. This study enhances our understanding of the conditions that paved the way for the Great Oxidation Event, a pivotal moment when oxygen levels rose in Earth's atmosphere, potentially spurred by the evolution of photosynthesis.