Landforms Of Depostition

Question 1

Spit

Answer 1

Longshore drift moves material along the coastline. A spit forms when the material is deposited.

Question 2

Bar

Answer 2

A ridge of sand or shingle which forms across the mouth of a river or entrance to a bay or harbour. Longshore drift transports sediment and deposits it.

Question 3

Tombolo

Answer 3

Change in the shape of the headland results in the formation of a spit.
The spit grows out from the mainland and joins to an island creating a tombolo.

Question 4

Storm beach

Answer 4

At the back of the beach, very powerful waves during storm conditions may deposit larger material forming a storm beach.

Question 5

Cuspate foreland

Answer 5

Formed when longshore drift comes from both ways.

Question 6

Breakpoint bar

Answer 6

Ridges of sediment with crests generally running parallel to the coast which form where steep destructive waves break.

Question 7

Berm

Answer 7

Smaller ridges that develop at the position of the average high tide marks resulting from deposition.

Question 8

Ridges and runnels

Answer 8

Occur in sand. They form parallel to the shore in the foreshore zone. Ridges are raised above the shore, either side of a runnel. They form as a simple drainage route for water.

Question 9

Cusps

Answer 9

Beach cusps are made up of various grades of sediment in an arc pattern. The horns are made up of coarser materials and the embayment contains all the finer grade sediment.

Question 10

Barrier islands

Answer 10

Narrow nearshore or offshore deposits of sand or sediments that are parallel to the coastline. The islands are separated from the mainland by a shallow lagoon. They are often found in chains and are separated by narrow tidal inlets. Glaciers melted after the last ice age, the sea levels rose and the contained sediment from the ice was released. Rising water pushed the sediment towards the land and was deposited in shallow areas just off the coast. Waves then continued to bring in sediment and build up the islands.

Question 11

What 5 things do you need to form a sand dune?

Answer 11

• large supply of dry sand
• large tidal range (sand has longed to dry/ wet sand cannot be picked up)
• gently sloping beach
• onshore winds that are 15kph + (sand picked up and blown by wind- saltation)
• object/obstacle (forms a windbreak, slowing down sand)

Question 12

How is a sand dune formed?

Answer 12

Sand piles up by and object and turns into an ever increasing wind break.
Sand piles into a dune at the back of the beach.
Sand is pushed over the dune crest, falling down the steeper windward slope.
The dune moves steadily inland.
Pioneer plants colonise the dunes.
Roots eventually hold sand in place.
New sand dunes build up behind the first dune.

Question 13

3 features of new/embryo dunes

Answer 13

• continually moving sand (covers up pioneers, no anchor points for roots, very abrasive to plant tissue)
• very little freshwater (rainwater rapidly percolates through coarse sand, no organic matter to retain water, salt from sea spray makes it hard for plants to absorb water)
• very few nutrients (there is no dead organic matter being recycled in the sand)

Question 14

Name 2 pioneer species for sand dunes

Answer 14

Sand couch grass

Lyme grass

Question 15

How are pioneer species adapted to live on sand dunes? 3 adaptions

Answer 15

• tolerant of salt (live closer to sea)
• waxy leaf coating (retains water)
• rolled leaves (reduces transpiration)

Question 16

Give 2 adaptions of marram grass for living on sand dunes

Answer 16

• can grow up to 1m per year (doesn’t get covered by new sand)
• can spread sideways up to 3m per year (helps to trap sand and keep it in one place)

Question 17

4 ways that conditions change moving inland on sand dunes

Answer 17

• exposure (wind) decreases
• less salt water, more fresh water so plants don’t have to be specialist
• more nutrients inland as more organic matter in soil
• very little sand movement as vegetation covers the dune

Question 18

Name the main plant on a mobile dune

Answer 18

Marram grass

Question 19

Name the plants found on semi fixed dunes

Answer 19

Many plants beside marram grass

Question 20

Name the plants found on fixed dunes

Answer 20

Marram grass is sparse

Many species of plants are present

Question 21

What plants are found in dune slacks

Answer 21

Short vegetation due to rabbits

Question 22

What plants are found in the climax of a sand dune?

Answer 22

Scrub and woodland

Question 23

What is succession?

Answer 23

Where primary succession takes place, only a few species can cope (pioneer species). Gradually over time conditions change and become more favourable to a wider range of vegetation types. The end stage is the climatic climax community, it is a community of vegetation adapted to the climate of the area.

Question 24

How is a salt marsh formed?

Answer 24

• Salt marshes start as mud flats
• in areas of sheltered water, sediment clumps together and sinks (flocculation)
• as plants arrive, their roots make mudflats more stable
• as the mudflats build up, plants can grow there and create a salt marsh habitat

Question 25

Where do salt marshes develop?

Answer 25

On depositional coasts where tidal action is fairly gentle.
E.g. Estuaries, enclosed bays, behind barrier islands, low energy coastlines
There must be very little wave action or fine particulate cannot build up.

Question 26

What sort of plants are salt marshes dominates by?

Answer 26

Halophytic (salt tolerant) plants

Question 27

Give 3 examples of salt marsh pioneer species

Answer 27

Glasswort
Cord grass (spartina)
Eel grass

Question 28

Give examples of how pioneer species are adapted to live in a salt marsh

Answer 28

Roots help to consolidate and bind mud
Spartina roots are 2m long and anchor the sediment
The upper parts trap more sediment 1-2cm/yr
When plants die the roots stay in the mud and hold it together

Question 29

What sort of plants are found in a salt marsh when mud height increases

Answer 29

Salt marsh grass

Sea aster

Question 30

As mud grows even higher on the salt marsh what is the vegetation like?

Answer 30

More species taking up more space and less bare ground. The muddy shore spends more time emersed (out of water). The plants grow bigger and exist is greater abundance.

Question 31

What plants are found at the top of the salt marsh?

Answer 31

(Damp)
Rush
Sedge 
(Dry)
Red fescue
If there's freshwater at the top of the marsh, it can develop into scrub and eventually forest.