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 ...

But these sorts of rocks have no fossils in them. The rocks that have fossils in them are formed very slowly underwater. Water carries sediment - sand and mud – that settles on the bottom of the lake ...

Potassium-Argon dating is similar to Carbon 14 dating because it uses radioactive decay, measuring the rate of change from an unstable isotope, to a stable one. This method is a little different from ...