Section 1 - Rivers (Erosional River Landforms)

Question 1

Explain the process of making a waterfall

Answer 1

1. They form where a river flows over an area of hard rock followed by an area of soft rock
2. The soft rock is eroded more than the hard rock, creating a step in the river
3. As water goes over the step it erodes more of the softer rock
4. A steep drop is eventually created from the step being eroded, which is called a waterfall

Question 2

How is a gorge created?

Answer 2

1. The waterfall is made
2. The hard rock is eventually undercut by erosion, becomes unsupported and collapses
3. The collapses rocks are swirled around at the bottom of the waterfall and erode the soft rock due to corrasion/abrasion, creating a deep plunge pool
4. Over time, more undercutting will lead to more collapses, causing the waterfall to retreat, leaving behind a steep sides gorge

Question 3

How are V-shaped valleys formed?

Answer 3

In the upper course of the river, the rivers aren’t powerful enough to erode laterally, so they have to erode vertically, creating steep sides, V-shaped valleys

Question 4

What are interlocking Spurs?

Answer 4

The hillsides that interlock with each other (like a zip) as the Tver winds around them

Question 5

Easy way to remember how waterfalls are formed:

Answer 5

Step over the hard rock and plunge into the pool

Question 6

Where are waterfalls and gorges found?

Answer 6

The upper course of a river