Geography - Costal landforms

Rock Type (Hard or soft rock) and Geological structures influence costal landforms.

Headlands are formed where there's a band of hard/resistant rock, which is eroded very slowly. Bays are formed where there's a band of soft rock that is much eaiser to erode - This created a sheeltered area where depostion occurs which forms a beach.

In a headland if theres a weakness it can get eroded by Hydraulic action & Abrasion which forms a Cave and if there are two back-to-back caves then it breaks through and becomes an Arch, which is eroded and becomes much bigger. Weathering attacks the roof of the arch and causes it to collapse leaving a Stack, which is eroded and collapses becoming a Stump.

When waves break against the cliff erosion occurs at the high-tide line forming a Wave Cut Notch and over time deepens undercutting the cliff the overlying cliff then collapses. This will over time cause the cliff to retreat and a genty sloping rocky platform - Wave Cut Platform is formed.

Beaches : found in sheltered areas- like bays. 

• Made from depostion of sediment over time.
• Sandy beaches are formed in areas with low energy waves. 
• Pebble beaches are formed in areas with higher energy coasts as the sand has been washed away.

Sand dunes 

• Embryo dunes form around obstacles, like rocks.
• Dunes develop and plants grow on top which stableizes the dune turning into Fore dunes and Tall Yellow Dunes.
• As plants decompose the sand becomes more fertile which means more plants grow on it.
• Ponds/ Dune Stacks form in the depressions.

Spits and Bars 

• Longshore drift carries sand along the coast but as the coastline changes a spit forms out to sea.
• but its faced with change in wind and wave direction which causes it to curve at the edge.
• Saltmarshes are found in sheltered areas behind spits. 

Bars occur when the spit grows all the way accros the bay