iron

Researchers: Half of iron atoms in some cores were processed by microbes 2.5 bya/Clark Johnson 2.5 billion years ago? That’s the theory here: These ancient deposits, up to 150 meters deep, were begging for explanation, says Johnson. Scientists thought the iron had entered the ocean from hot, mineral-rich water released at mid-ocean vents that then precipitated to the ocean floor. Now Johnson and Li, who is currently at Nanjing University in China, show that half of the iron in banded iron was metabolized by ancient bacteria living along the continental shelves. More. … Biologists say this process “is really deep in the tree of life, but we’ve had little evidence from the rock record until now,” Johnson says. “These ancient Read More ›