ABOVE: 3.42-billion-year-old chert veins (dark gray) in rocks at the Barberton Greenstone Belt in South Africa
AXEL HOFMANN
Researchers have discovered fossilized cell remnants in rock that roughly 3.4 billion years ago was a hydrothermal vein—a crack in bedrock containing superheated water. The microfossils, described today (July 14) in Science Advances, support the theory that such veins were breeding grounds for Earth’s earliest lifeforms, as well as the idea that primitive microbes were methane producers.
“On the basis of very detailed chemical analyses [the] filamentous . . . structures are interpreted as methane-cycling microbes,” Malcolm Walter, an astrobiologist at the Australian Centre for Astrobiology who was not involved in the study, writes in an email to The Scientist. “This is a significant addition to the very rare early Archean microfossil record.”
Hydrothermal veins in rock contain magma-heated ground water that rises to the surface as hot springs or geysers on land ...
