Coasts: Weathering Processes

What are the three types of weathering?

Mechanical, chemical and biological weathering.

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Mechanical weathering: freeze-thaw explained -

Water expands by 9% in volume when freezing, exerting a force within cracks and fissures; repeated cycles force cracks open and loosen rocks.

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Mechanical weathering: salt crystallisation explained -

The growth of salt crystals in cracks and pore spaces can exert a breaking force, although less than for freeze-thaw.

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Chemical weathering: carbonation explained -

The slow dissolution of limestone due to rainfall (weak carbonic acid, pH 5.6) producing calcium biocarbonate in solution.

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Chemical weathering: hydrolysis explained -

The breakdown of minerals to form new clay minerals, plus materials in solution, due to the effect of Walter and dissolved CO2.

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Chemical weathering: oxidation explained -

The addition of oxygen to minerals, especially iron compounds, which produces iron oxides and increases volume contributing to mechanical breakdown.

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Biological weathering: plant roots explained -

Trees and plants roots growing in cracks and fissures forcing rocks apart.

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Biological weathering: rock boring explained -

Many species of clams and molluscs bore into rock and may also secrete chemicals that dissolve rocks.

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Other cards in this set

Mechanical weathering: freeze-thaw explained -

Water expands by 9% in volume when freezing, exerting a force within cracks and fissures; repeated cycles force cracks open and loosen rocks.

Mechanical weathering: salt crystallisation explained -

Chemical weathering: carbonation explained -

Chemical weathering: hydrolysis explained -

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