Scientists date world’s oldest rock back to 4.02bn yrs
Canadian scientists have dated the world's oldest rock at 4.02 billion years old. The findings suggest the Earth's earliest crust was largely covered with an oceanic crust-like surface and not continental. The ancient rock is found to contain grains of zircon, which provide accurate dating. "Earth is constantly recycling itself, the crust is being deformed or melted", a researcher said.