Discordant Coastlines
The name Discordant coastline is given when there are bands of diffing rock type that run perpendicular to the coast at a right angle.
Headlands and bays occur on discordant coastlines due to the variation in rocktype hard rock outcrops named headlands and soft erroded rock forming bays between two headlines.
As the soft rock consisting of such types clays, sand and gravels are more resistant to erosion the rate of erosion is therefore faster. Erosion occurs between two headlands of harder more resistant rock and gently sweeping bays are formed. Studland and Swanage bays are examples.
The harder rock such as limestone and chalk, are more resistant to erosion and so erosion rates are alot slower, and the headland outcrops against soft rock formed bays make this example clear.
Headlands such as Pveril Point and Durlston Head are examples. Caves, arches, stacks and stumps form in the headlands.
Click play button the see how headlands and bays are formed.
Headlands & Bays animation
Quiz
Erosion rates
The alternate bands of hard and soft rock cause the differential rates of erosion forming the very irregular coastline of headlands and bays.
As waves enter shallower water towards the headland, this influence causes the wave fronts to bend and refract. Due to the refraction of these waves the waves energy is more concentrated towards the headlands, disipating as it reaches the bays.
Overtime erosional landforms occur in headlands. Erosion and weathering causes Caves, Arches, Stacks and Stumps to form.
Famous landform features in Britain include: