Waterfalls, Gorges and interlocking spurs

Question 1

Where does waterfalls form?

Answer 1

Where a river flows over a an area of hard rock, which sits above an area of soft rocks.

Question 2

How are waterfalls formed

Answer 2

1. As the river flows down, the softer rock is
   eroded by hydraulic action and abrasion
   more than the harder rock.
2. This creates a step in the river
3. As water flows into the step it erodes the
   softer rock even more.
4. A steep drop is eventually made

Question 3

How are gorges made

Answer 3

The hard rock of the waterfall becomes unsupported and collapses
- the materials of the cliff erode the soft rock by
abrasion creating a deep plunge pool
- The water retreats leaving a steep sided gorge

Question 4

Where does interlocking spurs occur

Answer 4

Upper course

Question 5

Why are interlocking spurs formed?

Answer 5

They erode vertically and lack the power to erode laterally, winding around high hill sites