A Feature of Erosion
- You should be able to provide a discussion on how both erosion and deposition landforms are created.
- My favourite feature of erosion is the waterfall. I think it’s the most straightforward landform to learn and the diagram is relatively easy to draw too.
- Learn off the following 15 SRP’s and you should be able to answer a question regarding an erosion landform on the day of the exam (Leaving Cert).
1. A waterfall is a feature of fluvial erosion and is found in the youthful stage of a river.
2. It is created when a river flows over bands of both hard and soft rock.
3. The river erodes the band of soft rock at a faster rate than it erodes the band of hard rock. This is causes a vertical drop zone along the riverbed. (see figure 1.1)
4. The band of soft rock is eroded by three processes; hydraulic action, abrasion and solution.
5. Hydraulic Action: the force of water removes rocks, soil and sediment from the river bed and river banks.
6. Abrasion: the river uses its load to breakdown the river bed and river banks.
7. Solution: the river itself dissolves the minerals contained in the rocks, gradually breaking them down.
8. These three processes occur simultaneously and at separate rates.
9. A vertical drop will develop along the riverbed overtime.
10. The band of soft rock will deteriorate at a faster rate and will allow a plunge pool to develop due to hydraulic action and abrasion. (see figure 1.2)
11. The aforementioned plunge pool may undercut into the face of the waterfall and an overhang might form.
12. This overhang may collapse due to gravity.
13. The waterfall may withdraw back up stream.
14. A gorge may develop where the waterfall withdraws up stream.
15. An example of a waterfall is Torc Waterfall in Killarney, Co. Kerry. (Try to reference a local waterfall).
- Fluvial Erosion
- Youthful Stage
- Hydraulic Action
- Plunge Pool
Relevant Exam Questions:
- Examine the impact of the processes of erosion on the formation of one fluvial erosion landform you have studied. (2017)
- Explain the formation of one landform of erosion you have studied.
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