Biology and Geology 3. Secondary Education Coastal features

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Transcript Biology and Geology 3. Secondary Education Coastal features

UNIT
8
Surface process
COASTAL FEATURES
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Erosive coastal features
Cliff
Arch
Cave
Transportation and sedimentary coastal features
Sand spit
Tombolo
Lagoon
Sand
bank
Beach
Marshes
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Cliffs
Cliffs are sharp slopes or
sheer vertical walls
between the land and the
sea.
They are formed as the
result of marine erosion
on rocky coasts.
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Arches
Arches are relief forms caused
by marine abrasion on a cliff.
They normally start from a
cave.
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Caves
Caves are natural
cavities which are
formed by the
wearing away of the
rocks on the coast
due to the effect of
abrasion of the
waves.
They usually form in
areas of the cliff
where the rocks are
softer.
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Tombolos
Mound
Spit
Biology and Geology 3. Secondary Education
These are mounds
which formed part of
the coast before it
was eroded away.
Following this
erosion, they are left
out at sea, but
attached to the coast
by means of a spit of
sand or gravel.
UNIT
8
Coastal features
Spits
These are long, thin sand banks, perpendicular to
the coast and attached to it at one end.
They are formed by the action of coastal currents.
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Sand spit
These are long sandbanks, parallel to the coast and attached to it at one
end.
They are formed by the action of coastal currents.
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Lagoons
Lagoons are bodies
of salt or brackish
water which are
formed on the coast
when a spit or bar
totally or partially
closes off a bay.
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Beaches
These are deposits
of sand or gravel that
are formed on flat
coasts, generally in
bays protected from
the waves.
Biology and Geology 3. Secondary Education
UNIT
8
Coastal features
Marshes
If the sandbanks
close off the estuary
of a river, the fluvial
sediments fill it in,
forming marshy
ground called a
swamp.
Biology and Geology 3. Secondary Education