Rocks break down into smaller pieces through weathering. Rocks and sediment grinding against each other wear away surfaces. This type of weathering is called abrasion, and it happens as wind and water rush over rocks. The rocks become smoother as rough and jagged edges break off.

What is abrasion caused by?

Abrasions are most commonly caused by falling, skidding, or other types of accidents. Many abrasions occur suddenly and without warning, and may not even be noticed until after the injury. Abrasions typically occur on the extremities, exposed arms and legs, when the skin is scratched against a hard or rough surface.

How does abrasion cause weathering?

Abrasion is another type of mechanical weathering. With abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a slope. ... This contact causes abrasion, which makes the rocks round.