When a researcher picks up an object — whether it’s a scrap of leather from a dig site, a fossil from a museum drawer or a newly fallen meteorite — their first question might be, “What is this thing?” ...

Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4.6 billion years. Mountains have been built and eroded, continents and oceans have moved ...

Paleolithic hunters built mammoth traps in what is now Mexico some 14,700 years ago. An unknown sea creature left footprints in sand some 550 million years ago, making them the oldest known footprints ...

We address the timing of Quaternary events using a relative dating technique that has a temporal range greater than that of some common absolute dating techniques. Originally, many of the sample types ...