Mechanical Weathering

Mechanical weathering is the process of breaking rocks into smaller pieces without changing their composition.

One common type of mechanical weathering is ice wedging. Imagine water seeping into tiny cracks in a rock. When the temperature drops, the water freezes, expands, and pushes the crack wider. Over time, this cycle of freezing and melting can break the rock apart completely.

Abrasion is another way rocks break down. Picture rocks tumbling down a hill or being carried by a river. As they bump into each other, they rub and wear down into smooth pebbles or even sand. Wind can also blow sand against rocks, chipping off tiny pieces bit by bit.

Plants and animals also help break rocks. A tree’s roots can grow into cracks and slowly force the rock apart as it expands. When burrowing animals, like moles or rabbits, dig through the soil, they break the rocks.

Humans also contribute to mechanical weathering. When we dig, build, or use explosives in construction, we break and reshape rocks, altering the landscape around us.