TEST OF PRACTICAL KNOWLEDGE QUESTION With the aid of diagrams, describe the mode of formation of the following features: (a) stack; (b) fold mountalin.

Answer Details

a) Stack Formation:

A stack is a tall column of rock that stands alone in the sea or on a coastline. It is formed by a combination of erosion and weathering.

First, the waves attack the base of a cliff, causing a notch to form. The notch deepens over time as more and more rock is eroded away. Eventually, the weight of the cliff becomes too much for the remaining rock to support, and a piece of the cliff breaks away from the mainland. This piece of rock is then shaped by the waves, forming a narrow pillar or stack. Over time, the stack may erode further and collapse, leaving only a stump or a small rock platform behind.

Diagram of stack formation:

                    ___
            /\     /   \
           /  \   /     \
          /    \ /       \
         /      X         \
        /      / \         \
       /      /   \         \
      /      /     \         \
     /      /       \         \
    /______/_________\_________\
          Cliff           Stack

b) Fold Mountain Formation:

A fold mountain is a type of mountain that is formed by the folding of rock layers due to tectonic activity. These mountains are characterized by their long, narrow shape and can be found all over the world.

The process of fold mountain formation begins when tectonic plates collide. As the plates push against each other, the rocks in the Earth's crust are pushed upwards and downwards. Over time, the rocks in the Earth's crust become deformed and folded, forming a series of ridges and valleys. The pressure and movement of the plates may also cause the rocks to fracture and fault, creating faults and fractures in the rock layers.

Diagram of fold mountain formation:

           _______________
          /               \
         /                 \
        /                   \
       /                     \
      /                       \
     /                         \
    /                           \
   /                             \
  /                               \
 /                                 \
/___________________________________\
            Fold Mountain

In summary, a stack is formed by erosion and weathering, while a fold mountain is formed by the folding of rock layers due to tectonic activity.