Ancient source of oxygen for life hidden deep in the earth's crust

Scientists at Newcastle University have discovered an oxygen source that may have influenced the evolution of life before the advent of photosynthesis.

The pioneering research project, led by Newcastle University’s School of Natural and Environmental Sciences and published today in Character Communications, has discovered a mechanism that can generate hydrogen peroxide from rocks during the movement of geological faults.

While at high concentrations, hydrogen peroxide can be harmful to life, it can also provide a useful source of oxygen for microbes. This additional source of oxygen may have influenced early evolution, and probably even origin.

In tectonically active regions, the movement of the Earth’s crust not only generates earthquakes, but riddles the subsoil with cracks and fractures lined with highly reactive rock surfaces containing many imperfections or flaws. Water can then infiltrate and react with these faults on the newly fractured rock.

In the lab, graduate student Jordan Stone simulated these conditions by crushing granite, basalt and peridotite, sorts of rocks that would have been present in the early earth’s crust. These were then added to water in well-controlled oxygen-free foods at varying temperatures.

Experiments have shown that substantial amounts of hydrogen peroxide – and therefore, potentially oxygen – were only generated at temperatures close to the boiling point of water. Importantly, the temperature of hydrogen peroxide formation overlaps with the growth ranges of some of the most heat-loving microbes on Earth called hyperthermophiles, including evolutionary ancient microbes using oxygen near the root of the plant. universal tree of life.

Lead author Jordan Stone, who conducted this research as part of his MRes in Environmental Geosciences, said: “While previous research have suggested that small amounts of hydrogen peroxide and other oxidants can be formed by stressing or crushing rocks in the absence of oxygen, this is the first study to show the vital importance of temperatures to maximize hydrogen peroxide generation.”

Principal researcher Dr. Lecturer Jon Telling added: “This research shows that faults in crushed rock and minerals can nt behave very differently from how you would expect more “perfect” mineral surfaces to react. All of these mechanochemical reactions must generate hydrogen peroxide, and therefore oxygen is water, crushed rocks and high temperatures.”

The work has was supported by grants from the Pure Environmental Exploration Council (NERC) and the British Isles Space Agency. A major new follow-up project led by Dr. Jon Telling, funded by NERC, is underway to determine the importance of this mechanism in supporting life below Earth.

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