demonstrate an understanding of the work of a river in eroding, transporting and depositing

•the formation of cliffs is when waves erode a coastline

          •1. undercut by all four forms of erosion 

                    •this forms a cliff notch 

          •2. this leaves the rocks of the cliff unsupported, so that they will eventually collapse 

          •3. collapsed material will be broken up by attrition and removed by waves

                    •the whole process is repeated  

•as the cliff retreats, it will leave behind a gently sloping wave cut platform

          •most are covered by the collapsed rocks from the cliffs which will form beaches

•caves, arches and stacks are formed in one eroding  process  

•bay and headland coastlines form on discordant coasts 

          •the different types of rocks means that it won’t erode at a constant rate causing differential erosion

•the softer less resilient rock erodes first, forming a bay leaving the harder rock projecting out as a headland 

•beaches are formed by the accumulation of sand and shingles 

          •the swash carries the deposits to the collapsed rock of attrition and longshore drifts carries further deposits

•the coarsest material is deposited at the upper limit reached by the swash and the backwash leaves the smallest material last 

•spits are formed when longshore drift is moving sand and shingle along a coastline

          •if there is a break (estuary or river mouth), longshore drift will continue to deposit sand, forcing the beach to grow away from the coast, creating a spit

                    •this will be long and narrow and have one end attached to the coast and one in open water

                              •there may be indents due to change in prevailing wind

                                        •salt marshes usually form behind spits as further deposition occurs and grasses grow

•coastal sand dunes are formed by strong onshore winds at the back of bridges and on spits

          •1. a strong onshore wind dries the sand and transports it inland

          •2. obstacles cause wind to slow and deposit sand

                    •this increases size of the obstacles i.e the dune grows

          •3. now dune forms on seaward side 

          •4. wind blows sand over the top of the dune and deposits it on the leeward side, moving them inland

          •5. salt-tolerant plants colonise between the dune an embryo-dune

          •6. embryo-dune joins up to form fore-dune 

          •7. the sand dune moves inland 

                    •as dunes move away from the sea, the are colonised by new plants 

                              •fixed dunes (at end before the dunes slacks) are the oldest and very stable

                                        •the water table comes to the surface to form small ponds - dune slacks