The dunes of all types advance by the deposition of sand on the steep leeward slip face, which usually develops a sinuous slipface with an angle generally between 32°â€“34° or steeper angles ...
That’s deposition. So, over a long period of time, sediment moves along the coastline in a zig-zag motion. So longshore drift has also helped to create the sand dunes by bringing all this sand ...