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.

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 ...

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 ...

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 ...