PRESENTATION OUTLINE
5 Agents of Mechanical Weathering
Animal Actions.
Animals that burrow in the ground loosen and break apart rocks in the soil.
Freezing and Thawing
When water freezes in a crack in a rock it expands. The process of frost wedging widens cracks in sidewalks.
Plant Growth.
Plant roots enter cracks in rocks. As roots grow, they force the cracks apart.
Release of Pressure.
As erosion removes material from the surface of a rock pressure on rock is reduced.
Abrasion
Sand and other rock particles that are carried by wind, water,and ice can wear away rock.
