Land Formations Flashcards
how are bays formed?
bays are formed on discordant coasts so their are multiple types of rocks. This means some rocks will erode faster than others (differential erosion). Overtime the softer rock such as clay will noticeable be eroded back quicker than the harder rock like limestone forming bays of softer rocks and headlands made of harder rocks
how are headlands formed?
headlands are formed on discordant coasts so their are multiple types of rocks. This means some rocks will erode faster than others (differential erosion). Overtime the softer rock such as clay will noticeable be eroded back quicker whilst the harder rock like limestone will be eroded away much slower forming bays of softer rocks and headlands made of harder rocks
how are caves formed?
caves happen when there are cracks that have formed along the fault lines in the rock. Water forces its way into the cracks and through hydraulic action and abrasion the rocks get eroded away until cracks become caves.
how are arches formed?
caves happen when there are cracks that have formed along the fault lines in the rock. Water forces its way into the cracks and through hydraulic action and abrasion the rocks get eroded away until cracks become caves. If this cave occurs on a headland then the cave keeps getting eroded away until breaks through to the other side forming an arch.
how are stacks formed?
give an example of a stack
caves happen when there are cracks that have formed along the fault lines in the rock. Water forces its way into the cracks and through hydraulic action and abrasion the rocks get eroded away until cracks become caves. If this cave occurs on a headland then the cave keeps getting eroded away until breaks through to the other side forming an arch. This arch keeps getting bigger as sea erodes away rock at the base until it can no longer support the top or the arch meaning the top collapses into the sea . This leaves a headland and a stack (tall pillar of rock)
old harry rock in the Isle of Purbeck in Dorset
how are stumps formed?
caves happen when there are cracks that have formed along the fault lines in the rock. Water forces its way into the cracks and through hydraulic action and abrasion the rocks get eroded away until cracks become caves. If this cave occurs on a headland then the cave keeps getting eroded away until breaks through to the other side forming an arch. This arch keeps getting bigger as sea erodes away rock at the base until it can no longer support the top or the arch meaning the top collapses into the sea . This leaves a headland and a stack (tall pillar of rock). The stack is attacked at the base until its weakened and eventually collapses to a stump.
how is a wave cut platform formed?
through hydraulic action abrasion and solution waves erode away at the bottom of the cliff forming a wave cut notch. This keeps getting bigger until the overhang becomes to great and due to the force of gravity it collapses into the sea and the cliff face retreats. This process repeated forms a wave cut platform
how is a spit formed?
a spit is formed when winds cause waves to hit the coast at an oblique angle creating a longshore drift. When sediment carried by longshore drifts hite the edge of a headland it is deposited and added on the the end. This repeated process forms a spit. If there is a river or estuary behind the spit then their currents stop the spit from continueing to grow to far out to sea. Also often salt marshes will form behind a spit
how is a bar formed?
how are salt marshes often formed?
how is the curved end of a spit often formed?
spits are often curved due to changes in wind direction
what is longshore drift?
when winds push the waves to hit the beach at a oblique angle. The swash of these waves moves sediment downshore whilst the back wash falls straight back down at a angle thats perpendicular to the coast. This creates a zig zag movement. This repeated process transports sediment.
What do steeper cliffs often indicate about the type of rock?
It’s harder rock
How are dunes formed?
