COASTS! Flashcards
what is the littoral zone?
a series of sub-zones to represent the features of the wider coastline from sea to land
sub-zones of the littoral zone:
foreshore
nearshore
backshore
offshore
what do concordant coastlines have?
alternating bands of hard and soft rock parallel to the coast
what kind of cliff profile do bedding planes that dip towards the sea create?
gentle
types of coastline:
discordant
concordant
names of coastlines:
concordant (aka Pacific coasts)
discordant (aka Atlantic coasts)
what is the dip?
the angle that the rock layer forms with the horizontal bedding plane
what is an example of a rock type in Dorset is most resistant to erosion?
Portland limestone
what are Dalmatian coasts?
made up of offshore islands and coastal inlets running parallel to the coast eg. Lulworth Cove, SW Dorset coastline
which kind of rock is most susceptible to erosion and weathering?
sedimentary
bedrock lithology:
igneous eg. basalt, granite
sedimentary eg. limestone, chalk
metamorphic eg. slate, marble
what are typical plants that colonise embryo and foredunes?
sea rocket and sea crouch- have deep roots and can tolerate high concentrations of salt
which type of dune plant can withstand high concentrations of salt from seawater?
halophyte
which are some mobile dunes nearer the sea?
yellow dunes
foredunes
embryo dunes
bedrock lithology:
the physical properties of different rocks
igneous rocks:
form from the crystallisation of magma
sedimentary rocks:
form from build up, compacting and hardening of sediments into layers over time by lithification
metamorphic rocks
formed from the change in the structure of sedimentary and igneous rocks, caused by variations in heat and pressure
types of wave:
constructive waves
destructive waves
what are the processes of erosion that affect coastal landscapes?
hydraulic action
abrasion
attrition
corrosion
corrosion:
when there is a chemical reaction between the seawater and susceptible rocks
abrasion:
where pieces of rock are picked up by waves and hit against the bed, beach or cliffs
hydraulic power:
where the force of the waves hitting against other rock causes the rock to break down
attrition:
where pieces of bedload are hit against one another
erosion of headland -> landforms:
cave
arch
stack
stump
formation of wave cut platforms:
erosion causes a wave-cut notch to form
erosion of the wave-cut notch causes the rock above it to collapse
waves wash away the collapsed material and begin eroding the cliff again
multiple collapsing events lead to the cliff retreating leaving behind a wave-cut platform
examples of coastal landforms created by the erosion of headlands:
cave
stack
arch