Many of the world's highest mountain ranges are fold
mountains. They began to form millions of years ago when plates pushed together.
The Himalayas and Alps are chains of fold mountains. Some mountains, such as
Mount Everest, are still growing in this way.
If pressure builds up under the Earth's surface, brittle
rocks in the crust may crack. Cracks in rocks are called faults. If two faults
occur close together, the chunk of crust between them may be pushed up or slip
down below the surrounding rock. Chunks that are pushed up are called block
mountains or horsts. A low area between two horsts is called a rift valley.

The most famous rift valley is the Rift Valley in East
Africa. The Rhine Valley in Germany and Death Valley in the USA are also rift
valleys.
In some areas, currents of magma under the crust flow
together from opposite directions. The pressure may squeeze the crust and make
it buckle and form folds such as those shown here:

The Alps are a young fold mountain belt (30-40 million years
old) spread over parts of: France, Italy and Switzerland. The area was covered
in glaciers during the last ice age and they have left behind features such as
pyramid-shaped mountain peaks, U-shaped valleys and long, ribbon lakes. As
altitude (height) increases, the climate becomes colder and this affects land
use:

- Farming
is traditionally carried out on the valley floors where the soils are
deeper and more fertile. On the sunnier south-facing sides, fruit can be
grown. In the winter, farmers keep their animals on the valley floor until
the snow melt in the spring means they can be moved back onto higher
pastures.
- With
its central location in Europe, tourism is now a major industry. There are many places in the Alps which
tourists are attracted to visit, such as Chamonix and St Moritz. Sports
such as skiing and sledging are popular in the winter, whilst hiking and
climbing are popular in the summer when there isn't any snow. The money
brought into Alps have helped improve transport links, with many new roads,
railway lines and cable cars being built. At 16.4km (10.2 miles) long, the
St. Gotthard Tunnel is the third-longest road tunnel in the world.
- Many
of the Alpine slopes up to 1,800m are covered with coniferous trees. Their
wood is used for: fuel, building material and paper making. In Switzerland,
the wood is also used to make cuckoo clocks.
- The
fast-flowing rivers fed by snowmelt and high mountain gorges which are
easy to dam make the Alps a great place to generate hydro-electric power
which can be used by local industries.
The Alps are a challenging place to live however because:
- the
steep mountain slopes make it difficult to build houses and roads on;
- there
is little flat land to farm on;
- heavy
snowfall can make travelling difficult during the winter;
- areas can be at risk from sudden snowfalls from
mountain sides called avalanches.
|