Wherever you are now, there are rocks below you. Even
if you are standing on the beach, digging in the garden, swimming in the
sea or rowing across a river, there are rocks somewhere beneath your feet.
are many different rocks, from soft mudstone and crumbly sandstone to
hard granite. Some rock splits in sheets - like slate. Some rocks are
rare and valuable - like gold and diamonds.
But why, if there are rocks everywhere, are they often covered in earth
and stones? Rocks break down. Ice cracks them. Water tumbles them. They
are rubbed together. They break into smaller and smaller bits. These small
bits mix with the remains of plants and animals to make earth or soil.
Sandy soil has big bits in it. Water passes through it easily. The big
bits are stopped by a sieve. Clay soil has tiny bits in it. It holds water.
Its tiny bits pass easily through a sieve.
We can use rocks and soils in different ways. Hard rocks are good for
building. Loam - a mixture of clay and sandy soil - is good for growing