Formation Of Rocks

The ground beneath your feet is not as still as it looks. Granite kitchen worktops, the slate on a roof, the limestone in a cathedral and the marble of a statue all began as something else and were made over by heat, pressure, water and time. Geologists group every rock on Earth into just three families, and each family tells the story of how it was born. Learn to read those stories and you can pick up almost any rock and say where it came from.

In this lesson you will see how igneous, sedimentary and metamorphic rocks form, and how the rock cycle links all three so that one rock type can slowly become another. You will also meet permeability, the property that decides whether water soaks through a rock or runs off it. These ideas underpin everything that follows in this unit, from where we mine metals to where groundwater is stored.