Physical Weathering

A weathering process which causes the disintegration of rocks, without chemical interactions. This is also termed mechanical weathering.

Physical weathering can result from several actions, including:
• Abrasion, which wears down the surface of rocks and minerals. This can result from the action of sand particles in wind, or the erosion of riverbanks or beds being worn away due to stones, sand, or other materials, being carried by moving water.
• Freezing of water expands the cracks in rocks where the water is present. The subsequent thawing of the ice relieves the pressure, but with regular freezing and thawing the rock will start to shatter and break apart.
• Animals can burrow, dig and scrape away at rocks and minerals, gradually weakening them, making them more liable to further physical weathering.
• The action of plant roots can also contribute to cracking of soils and minerals as the roots expand through the material.
• Thermal expansion and contraction due to heating and cooling, especially where there is a large different in the temperature range. This creates stress fractures and fissures within rocks and minerals, which can start the disintegration process.