A WORLD OF ROCK

We live on the surface of giant ball of rock, the Earth. The oldest rocks discovered so far on our planet are in northwestern Canada. They are about 4 billion years old. Other rocks are much more recent, and new rocks are forming all the time.

Rocks develop in different ways from hot,melted rock, from the fossil remains of animals and plants that solidify into rock over millions of years, and by the action of heat and pressure on ancient rocks inside the earth.

no rocks, however tough, last forever. They are worn away over time by water, wind and other powerful force of erosion. The earth's rocks are full of extremely valuable burried tressure. They give us preciuos stones, precious metals and vital resources such as iron and coal.

Source : Rocks and fossils [Margaret Hynes]