Weathering and Erosion - Part 1 PDF
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Uploaded by Mr Wight
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Summary
These notes explain weathering and erosion processes. They detail how physical and chemical processes break down rocks, including factors like temperature changes, water, ice, salts, and the role of plants and glaciers. The notes also discuss erosion as the removal of weathered particles.
Full Transcript
Weathering and erosion Weathering • The physical and chemical processes that break rocks down Physical weathering • Weathering can happen because of: • • • • • Temperature change Water and ice Crystallization of salts Wind Living plants Temperature • Solids expand when they are heated and con...
Weathering and erosion Weathering • The physical and chemical processes that break rocks down Physical weathering • Weathering can happen because of: • • • • • Temperature change Water and ice Crystallization of salts Wind Living plants Temperature • Solids expand when they are heated and contract when they are cooled. • The same happens with rocks except this can crack rocks Ice and water • Can split rocks by freezing water • As the ice expands it widens cracks in rocks Salts • As salts crystalise in rocks they weather them Glaciers • They are like frozen rivers of ice that move along valleys very slowly • As they move, the ice scrapes pieces off the surrounding rocks, forming valleys that are U shaped Water • Water running or washing over rock can also wear them away Wind • Fine particles of rock carried blast the rock surface Plants • Plants growing through rocks can split them Chemical weathering • Involves water and chemicals in the water and air reacting with the rock and changing it • E.g. dolerite reacting with Oxygen. The iron in it forms Rust and as it does it doesn’t hold the dolerite together acid • Acid rain which contains dissolved acids can dissolve the rock Erosion • Small particles of rock broken off by weathering can be carried away by water, wind and ice • The removal of rock particles is called erosion
