Surprising Signs of Oxygen on Earth, 2.5 Billion Years Ago

Two teams of astrobiologists studying rock samples from deep underground have concluded that significant traces of oxygen emerged in Earth's atmosphere 50 million to 100 million years earlier than previously thought.

Of course, that's good news for any of us planning a little time machine jaunt back to the volcanic paradise of the planet's early days. But even more importantly, it sheds light on how early organic material might have evolved here on Earth.

Scientists have previously observed that oxygen in the Earth's atmosphere jumped up sharply from very low levels between 2.3 billion and 2.4 billion years ago, in what has been dubbed the Great Oxidation Event.

One explanation for this jump has been that early plant-like organisms had begun to produce oxygen via photosynthesis. However, many scientists think the proto-plants in fact began expelling oxygen much earlier, but that it was largely destroyed in chemical reactions with volcanic gases and rocks.

The new findings give additional credence to that theory, the researchers said:

"What we have now is new evidence for some oxygen in the environment 50 to 100 million years before the big rise of oxygen,"
said (Ariel Anbar, an associate professor at Arizona State University,
Tempe, and leader of one of the research teams). "Our findings strengthen the notion that organisms learned to produce oxygen long before the Great Oxidation Event, and that the rise of oxygen in the atmosphere ultimately was controlled by geological processes."

The study, funded by NASA and the National Science Foundation, brought together teams from five Universities in the United States and Canada, analyzing a .6-mile-long drill core taken from Western Australia.

NASA Research Indicates Oxygen on Earth 2.5 Billion Years Ago [NASA press release]

(Photo:
Eruption in Stromboli, Eolie Islands, Italy.
Credit:Ibcbulk.)