Erosion

Question 1

Hydraulic Action

Answer 1

The force of the water pushing against a point or crack in a rock can compress the air in the rock, putting pressure on the surrounding rock face. After a time the rock will break apart and be carried downstream.

Question 2

Attrition

Answer 2

Load is carried in the river and collide together, breaks up into smaller particles. Rough edges become smooth and rounded, they continue to get smaller, eventually becoming particles.

Question 3

Solution/Corrosion

Answer 3

Chemicals in water or the water itself in a river can dissolve minerals in rocks such as chalk and limestone. These dissolved chemicals then travel away down the river.

Question 4

Abrasion

Answer 4

Large rocks on the river bed, being dragged by traction, scraping the river bed, eroding it away. If the boulder gets caught in a swirling current, then it could result in a pothole being formed, where the boulder has been twisted round, creating potholes.