- Water: Through the process of hydrolysis and oxidation, water can dissolve and break down rocks.
- Ice: Occurs when water seeps into cracks in rocks and freezes. As it freezes, the water expands and exerts immense pressure on the rocks, causing them to break down.
- Temperature Changes: Extreme variations in temperature can lead to weathering. The expansion of rocks occurs when heated, and the subsequent contraction when they cool can weaken them, causing them to fracture and break down.
- Biological Activity: Roots of plants can penetrate and break apart rocks. Animals, such as burrowing organisms, loosen and break down the soil.
- Chemical Reactions: Minerals within rocks can react chemically with elements found in the atmosphere, including oxygen, carbon dioxide, and water. These chemical reactions can cause the minerals to break down into smaller components, altering the composition and structure of the rocks.
Erosion is the process by which weathered materials are transported from one location to another. The main agents of erosion are:
- Water: Rivers, streams, and other bodies of water can erode soil, sand, and other loose materials.
- Wind: Wind can carry away dust, sand, and small particles, especially in dry environments.
- Ice: In mountainous areas and glaciers, ice can transport debris through the process of ice movement.
- Gravity: Gravity pulls loose materials downhill, causing erosion in the form of landslides and rockfalls.
Deposition is the process of depositing and accumulating eroded materials in new locations. The agents responsible for deposition are the same as those involved in erosion:
- Water: Bodies of water, such as rivers and deltas, form new land through the deposition of sediments.
- Wind: In arid environments, wind can create dunes and other landforms by depositing sand and dust.
- Ice: As glaciers melt, they leave behind deposits of sediments known as moraines.
- Gravity: Through landslides, rockfalls, and avalanches, gravity also contributes to the accumulation of materials.
