Coastal Landforms

• Coastal landforms resulting from erosion

  • Headlands and bays
  • Cliffs and wave cut platforms
  • Caves, aches, stacks, and stumps
• Coastal landforms resulting from deposition

  • Beaches
  • Sand dunes
  • Spits and bars
• Discordant coastlines occurs where bands of different rock types run perpendicular to the coast
• Cordant coastlines occurs where bands of different rock types run parallel to the coast
• Headlands and bays form on discordant coastlines where the softer rock erodes faster creating a bay

  
• Soft rock erodes quickly forming gentle sloping cliffs but hard rock forms steep cliffs
• Wave cut platforms are created from more resistant cliffs

  A) Wave cut notch

  B) Wave cut platform

  
• Erosion of a headland

  A) Crack

  B) Cave

  C) Arch

  D) Stack

  E) Stump

  
• Beaches are formed from sand and shingle or pebbles
• A sandy beach usually forms in sheltered bays where low-energy constructive waves transport material onto the shore
• Spit

  • Longshore drift transports sediment and continues off mainland and is deposited in shallow water
  • Spits can curve due to a secondary prevailing wind
  • Saltmarshes can form behind a spit if an estuary is present
• Bar

  • A bar is a ridge of sand or single that joins two headlands on either side of a bay
  • It is formed due to longshore drift transporting sediment along the coastline
  • Behind the bar a lagoon is created
• Sand dunes

  • Sand is deposited by the wind around an object such as a rock, forming embryo dunes
  • Over time, vegetation such as marram grass stabilise the sand dunes forming foredunes
  • As the vegetation around the foredunes decomposes nutrients are released and soil begins to form