Erosion types and erosion features on a coast........

Marine erosion and erosion landforms.

Erosion 

Hydraulic action

Abrasion

Attrition

Solution

Sub-aerial weathering-coastal process not linked to sea-

Freeze thaw- Freeze-thaw weathering can also be called frost shattering. Water may get into a crack in a rock and freeze. As the water turns into ice it expands and causes the crack to open a little. When it thaws the ice melts and changes back to water. Repeated freezing and thawing weakens the rock causing rock to break off.

Biological weathering - Plant seeds get into cracks in rocks and begin growing. As they grow, they exert pressure on the rocks, causing them to fracture.

Chemical weathering- Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.

Exfoliation

The repeated action of heating and cooling rocks causing them to “shed” off layers.

Mass Movement - is the movement of material down hill due to gravity. 

(Landslides- slumping) - rain sinks through porous rocks, prolonged rainfall increases weight of the cliff.Large saturated rocks fall off.

Rock fall- is free rocks on steep cliff fall of a steep cliff face, due to gravity.It is made worse by weathering,which loosens the rock. At the bottom of the cliff the fallen material forms a scree slope.

Soil creep is the slow movement of material down hill due to gravity it occurs on gentle slops.

EROSIONAL LANDFORMS-

Headlands and bays- found on layers of alternating rock. Where less resistant rock meets resistant rock at the coast at right angles.

Formation of bays and headlands after erosion

Softer rock erodes quicker that hardrock , headlands are formed from rock which is more resistant.

Discordant coastline before