Unique landforms occur at plate margins!

How fold mountains are formed

1. sediment from rivers is deposited in the sea and settles on ocean floor

2. over time = layers of sediment build up

3.  techtonic plate move together and squash sediment upward = fold mountain

An example of fold mountain: THE ALPS

How oceon trenches are formed

At some points, the oceanic crust bends downward and forms a deep-ocean trench.

1.  oceonic crust sinks into mantle = subduction

2. friction when continental and oceanic crust meet

3. form trench as a result/ example of oceon trench: JAPAN TRENCH

CASE STUDY OF FOLD MOUNTAINS : THE ANDES IN PERU

USE: Farming is at high altitude and fields are cut into the steep slopes.

Subsistence farming on terraces  cut into mountainside. potatoes, veg)

The flat area traps water and limits soil erosion - the soil is very thin

Use of animals - llamas

female: wool, milk, meat

male:transport, can carry 25% of their own body weight