A team of scientists including Carnegie's Dina Bower and Andrew Steele weigh in on whether microstructures found in 3.46 billion-year-old samples of a silica-rich rock called chert found in Western ...

A million years ago, dry seasons became more frequent and forests retreated before the encroaching savanna. Meanwhile, clustered around a nearby lake, our ancient ancestors fashioned stone tools.

The Pilbara region of Western Australia is home to one of the most ancient surviving pieces of Earth’s crust, which has been geologically unchanged since its creation some 3.5 billion years ago. Some ...

Tiny crystals of iron oxide in ancient Australian rocks offer evidence that the Earth’s atmosphere held significant amounts of oxygen far earlier than previously thought, a new study suggests. Large ...

Reconstruction of an ancient marine environment from 3,400-million-year-old rocks in South Africa strengthens the case for the existence of photosynthetic microbes at that time — but adds a fresh ...

Life first appeared on Earth about 3.5 billion years ago, after the planet's formation 4.6 billion years ago. Fossils presumed to be from this period serve as the evidence. However, the authenticity ...

The global ocean covering the Earth 3.4 billion years ago was far cooler than has been thought, according to researchers who analyzed isotope ratios in rocks formed on that ancient ocean floor.

Researchers trying to study the earliest signs of life on Earth have a tall task—it would be easier to find a needle in a haystack. Not much of the rock that formed at the surface of the Earth over ...