Billion years ago, shattered quartz reacted with water, providing the necessary conditions for the evolution of photosynthetic microorganisms that produce most of the oxygen in today’s atmosphere.
Quartz is the most common silicate mineral. (Photo: Inverse).
Earthquakes and many other geological processes facilitated reactions that produce oxygen, impacting the evolutionary process of some of the earliest organisms on Earth. Researcher Mark Thiemens from the University of California, San Diego, and his colleagues ground quartz and exposed it to water under chemical conditions similar to those on Earth before oxygen levels rose. They used quartz because it is the simplest and most common silicate mineral, as reported by New Scientist on March 20.
The research team found that fractured surfaces of quartz crystals can react with water to form oxygen molecules and other oxygen-containing compounds like hydrogen peroxide. Also known as free radicals, these molecules are crucial to the early evolutionary process because they can damage DNA and other cellular components, according to researcher Timothy Lyons from the University of California, Riverside. He suggests that life may have developed enzymes early on to counteract the harmful effects of free radicals.
In nature, quartz and some other silicate minerals can be ground down by earthquakes, erosion, or shifting ice. They can then interact with water to produce oxygen molecules. Thiemens and his colleagues estimate that earthquakes alone could produce more than 100 billion times the amount of hydrogen peroxide compared to reactions in the atmosphere, representing another potential source of oxygen.
Adaptations to the oxygen from seismic activity may have helped some organisms survive significant changes in chemical conditions on Earth, associated with the Oxygen Catastrophe. Researchers state that similar geological processes occurring on other celestial bodies, such as dust storms on Mars or tidal fluctuations on Saturn’s moon Enceladus, could also generate oxygen.
Today, oxygen constitutes about one-fifth of the Earth’s atmosphere, largely produced by plants and microorganisms. There was very little oxygen in the atmosphere until it spiked during the Oxygen Catastrophe event, approximately 2.3 to 2.4 billion years ago, due to the rapid proliferation of microorganisms releasing oxygen through photosynthesis.
