coasts Flashcards
disconcordant
-right angle to the coastline
-different rock types
-creates headlands and bays
concordant
-parallel to the coastline
-one type of rock
A spit
A spit is an extension of the headland by long shore drift
A tombolo
forms when long shore drift connects sediment to an island
A bar
forms because there is no river flow between headlands so longshore drift deposits sediment continually
mass movement
is a vertical(movement of material (saturated with water)
-the shifting of rocks and loose material down a slope, it happens when the forcee of gravity on a slope is greater than the force supporting it
mechanical weathering
the breakdown of rock without changing its chemical composition
chemical weathering
the breakdown of rock by changing its chemical composition. occurs when warm and wet
biological weathering
the breakdown of rock by living things e.g plant roots break down rocks by growing into cracks on their surface and pushing them apart
constructive waves
-strong swash which transports sand up the beach
-the backwash is weaker so dosent take a lot of material back down the coast
-deposit more material than they erode
destructive waves
-create a steep beach profile
-weak swash
strong backwash, eroding sand from the beach
how do waves erode the cliff to form wave-cut platforms?
1) waves cause most erosion at the foot of a cliff
2) forms a wave-cut notch, enlarged as erosion continues
3) rock above notch becomes unstable eventually colapses
4)collapsed material is washed away new wave-cut notch starts to form
5)repeated collapsing results in cliff retreating
What are headlands eroded to form
1) crack
2)cave
3) arch
4) stack
5)stump
Crack
Large crack, opened by hydraulic action
Cove
Crack grows into a cave by hydraulic action and abrasion
