Rock record shows signs of oxidation 200 million years earlier than previously thought
OXYGEN’S ORIGINS The first whiff of oxygen in Earth’s oceans came 200 million years earlier than previously known, new research finds. The oxygen-breathing organisms responsible were probably the forebears of modern cyanobacteria, shown.
The first oxygen-producing life-forms appeared hundreds of millions of years earlier than previously known, new evidence suggests.
Analyzing iron and uranium embedded inside primeval rocks, researchers discovered that shallow seawater contained whiffs of dissolved oxygen around 3.2 billion years ago. The new date places the appearance of Earth’s oxygen around 200 million years earlier than previous studies, the researchers report online August 24 in Earth and Planetary Science Letters.