Landforms of Deposition Flashcards
How are beaches formed?
Formed when constructive waves deposit sediemtn on the shore.
What is a shingle beach like?
Steep and narrow.
Madeup of larger partcles which pile up at steep angles.
What is a sand beach like?
Formed from smaller particles, wide and flat.
What are the associated features of a beach?
Berms, runnels, cusps.
What are berms?
ridges of sand and pebbles (1-2 metres high) found at high tdie marks.
formed by deposition of coarse material at the limit of the swash.
What is a runnel?
Grooves in the sand running parallel to the shore.
Formed by backwash draining to the sea.
What is a cusp?
Crescent shaped indentations that form on beaches of mixed sand and shingle.
Where does a cusp form?
Develop in areas where waves break parallel to the beach and where there is a large tidal range.
Where does a spit form?
Form where the coast suddenly changes direction. e.g. across river mouths.
Process of spit formation
1) LSD- sand and shingle out to sea
2) Recurved from changes to dominant wind/wave
3) New growth- several recurved ends formed/abandoned from regualr changes.
4) Mature Spit- Area behind spit shelted, mudflats/saltmarshes form.
What is a bar?
Where a spit joins two headlands together.
Can occur across a bay or a weak river.
Lagoon forms behind it.
Sand Dunes
Formed when deposited sand is moved up the beach by the wind.
How is a sand dune formed
Pioneer species, stabilizes and blocks more and more sand and is colonised, forming embryo dunes.
Moves up beach, more embryo dunes formed, become smature dune.
What is a salt marsh?
An area of sheltered water.
Silt and mud deposited by river or tide, mudflat forms.
Colonised by salt tolerant vegetation that can stand long periods of submergence.
Plants trap more and more silt and mud. Creates a marsh that is exposed for longer and longer.
