Research Challenges "Whiff" of Oxygen Present in Earth's Deep Past

Recent research by Professor Sarah Slotznick challenges the view that scientists proposed in 2007 of a "whiff" of oxygen present before the Great Oxygenation Event more than 2 billion years ago. Most geological evindence suggests that before this event, atmospheric oxygen levels were low. However, in 2007 researchers reported evidence of trace amounts of oxygen in samples 2.5 billion years old. Newer research now suggests that the study conclusions relied on a methodological error. Using new analysis tools, researchers have challenged this notion and suggested that a series of changes that were present after sediments were deposited on the sea floor were responsible for the oxygen signal.

"Without the whiff of oxygen reported by a series of earlier studies, the scientific community needs to critically re-evaluate its understanding of the first half of Earth's history," says Dr. Slotznick.

You can read more about this research in a Cosmos article: "Rock sample re-writes Earth's early atmospheric history - again".