Coastal weathering and erosion

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  • Created by: Jess
  • Created on: 10-06-13 19:21

Weathering is the breakdown of rocks where they are, erosion is when rocks are broken down and carried away by soemthing, e.g. seawater.

Rock is broken down by mechanical and chemical weathering.

1) Mechanical weathering is the breakdown of rock without changing its chemical composition. There's one main type of mechanical weathering that affects coasts- freeze-thaw weathering.

It happens when the temperature alternates about and below 0 degrees ( the freezing point of water). Water gets into cracks in the rock, e.g. granite. When the water freezes it expands, which puts pressure on the rock. When the water thaws it contracts, which releases the pressure on the rock. Repeated freezing and thawing widens the cracks and causes the rock to break up.

2) Chemical weathering is the breakdown of rock by chaning its chemical composition. Carbonation weathering is a type of chemical weathering that happens in warm and wet conditions:

Rainwater has carbon dioxidedissolved in it, which makes it a…

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