Erosional landforms include V-shaped valleys, interlocking spurs, waterfalls and gorges. Meanders and oxbow lakes use erosional and depositional processes in their creation.
The process of erosionThe wearing away of pieces of rock, soil or other solid materials. can create different landforms. The erosional features are often found in the upper courseThe highest section of a river located in the mountains. of the river.
Waterfalls and gorges
A waterfallA steep drop in a river. is a sudden drop along the river course. It forms when there are horizontal bands of resistant rock (hard rock) positioned over exposed, less resistant rock (soft rock).
The soft rock is eroded quicker than the hard rock and this creates a step.
As erosion continues, the hard rock is undercut forming an overhang.
abrasionWhen rocks carried by the sea water wear away the landscape, eg cliff face/headland. and hydraulic actionErosion caused by the force of river water hitting cracks in the side of the river bank. The air in the cracks becomes compressed and then explodes outwards, breaking off bits of rock. erode to create a plunge poolThe pool of water found at the bottom of a waterfall. It is an erosional feature which has been created by a combination of hydraulic action and the abrasion of the plunging water..
Over time this gets bigger, increasing the size of the overhang until the hard rock is no longer supported and it collapses.
This process continues and the waterfall retreats upstream.
A steep-sided valley is left where the waterfall once was. This is called a gorgeA deep, narrow passage that usually has a river running through it..
V-shaped valleys and interlocking spurs
In the upper course there is more vertical erosionWhen the land is eroded or worn away in a downwards direction, eg a river that is high up will erode vertically because gravity pulls the water downwards.. The river cuts down into the valley to form a narrow, steep-sided V-shaped valley. If there are areas of hard rock which are harder to erode, the river will bend around it. This creates interlocking spurHill that a river meanders around in a V-shaped valley. When viewed from downstream, these spurs appear to be locked together. of land which link together like the teeth of a zip.