Depositional landforms

• Beaches


  • The most common coastal depositional landform
  • Form from sediment (sand, shingle, pebbles) deposition from material from cliffs, up the coast, or sediment carried in rivers and sea water
  • Often form in bays or more sheltered areas, as they have lower wave energy, and the reduced water velocity aids gravity settling
  • Sediments like sand get trapped in bays
• Micro-features of beaches


  • High tide ridges called berms
  • Storm beaches at the backshore
  • Offshore ridges or bars
• Clasts (sediment grains) on beaches


  • Get bigger up the profile towards the land, because smaller sediments are removed by wave action, storms throw larger clasts up the beach, and large clasts from cliffs remain towards the back of the beach
  • Tend to get smaller and rounded along beaches, due to the attrition process
• Spits


  • A long narrow strip of land which is formed due to deposition
  • Unique, distinctive landforms, but not very common at all
  • Formed by longshore drift, where waves lose energy (normally due to going into a sheltered area such as behind a headland) and deposit their sediment
  • Require a significant change in the direction/shape of the coastline for the sediments to project outwards into the marine water, rather than follow the coast more
• Examples of spits


  • Spurn Head spit, Holderness Coast
• Formation of hooked or recurved spits


  Prevailing wind changes direction and a secondary wind blows from another direction, hooking the end of the spit
• Sheltered area behind a spit

  Can turn into a salt marsh over time
• Length of a spit


  Influenced by surrounding currents or rivers, e.g. a spit forming in an estuary can be shortened by the current from the river preventing deposition across the bay