Mechanical Weathering - GCSE Geography Definition

Mechanical weathering, also known as physical weathering, is the process by which rocks break down into smaller pieces without changing their chemical structure. It occurs due to physical forces, such as changes in temperature, freezing and thawing of water, and the actions of plants and animals. For example, when water gets into cracks in a porous or permeable rock and freezes, it expands and exerts pressure on the rock, causing it to split. Over time, this repetition of expansion and cracking can turn large rocks into smaller ones, sand, or even soil. Mechanical weathering is an important natural process that helps shape the landscape and contributes to the creation of soil that supports plant life.